Food and nutrition
Fruit
Fungi
Gene expression
Gene regulation
Gene therapy
Genetic inheritance
Genetic mutations
Genetic tools
Gymnosperms
Homeostasis
Human development
Human evolution
Human impact on the biosphere
Human reproduction
Immunity
Infectious diseases
Insects
Lichen
Metabolism
Mitosis and Meiosis
Molecular transport
Mollusks
Muscular system
Nervous system

Smithsonian: Algae research
A general description of Algae and a look at the Smithsonian's collection and preservation of algae species.

UC Berkeley: Green Algae
UC Berkeley's biology website on algae. Includes information about algae in the fossil record, life history and ecology, systematics, and morphology.

Red tide fact sheet
Red Tide poisoning and symptoms. Learn how the toxins are amplified through the food chain.

Centers for Disease Control and Prevention: Chlamydia
Fact sheet on Chlamydia, its symptoms, treatment, and its prevention.

Tree of Life Web Project
An overview of angiosperms evolutionary history and characteristics. Includes information from the fossil record and phylogenic relationships in the angiosperm evolutionary tree.

UC Berkeley: Intro to angiosperms
UC Berkeley's biology website on angiosperms. Includes information about angiosperms in the fossil record, systematics, and morphology.

Angiosperms
A description of monocots and dicots, leaf arrangement, flower structure and arrangement for multiple flowers, and fruits.

Seed evolution
A comprehensive look at seed evolution with plenty of visuals. Check out the phylogenic trees and examples of what the earliest seeds looked like.

ANTHOPHYTA Life Cycle
Angiosperm life cycle and reproduction. Gives a visual walkthrough of the stages of the life cycle as well as quiz at the end to test what you've learned.

Animal Behavior Society Web Site
The Animal Behavior Society is a non-profit scientific society, founded to encourage and promote the study of animal behavior. Read essays on animal behavior and click on "articles" to see an up-to-date list of articles on animal behavior.

Association for the Study of Animal Behaviour
ASAB is an organization created for the promotion of the study of animal behavior.

Behavioral Ecology
A journal that covers work in the field of behavioral ecology. Use the search function to learn more about the behavior of your favorite animal.

Association of Zoos & Aquariums
AZA is dedicated to the advancement of animal care, wildlife conservation, and education. Go to the "resource center" to learn about animal behavior and conservation efforts.

Social Animals and Human Customs
Social animals, from insects to great apes, reveal how human customs and traditions evolved.

Social intelligence: from brain to culture
A collection of papers from the speakers at the discussion meeting on 'Social intelligence: from brain to culture' will be published in a special issue of Philosophical Transactions of the Royal Society B: Biological Sciences

Periodic Table of the Elements
An interactive periodic table from the Los Alamos National Laboratory. It provides the atomic and mass numbers of every known element, as well as histories of their discovery and their biological significance.

WebElements
The Scholar Edition of this site provides an interactive periodic table linked to a wealth of information.

Caloric Confusion
The fascinating story of how researchers used isotopes to determine how accurately subjects reported their food intake. This is on a PBS NOVA site.

Marie and Pierre Curie and the Discovery of spontaneous radioactivity
This essay on the Nobel Foundation site describes the Curies' research on radioactivity. The couple shared the Nobel Prize in Physics in 1903 and Marie won the Nobel Prize in Biology in 1911.

Marvelous Molecules
The NY Hall of Science provides these examples of familiar organic molecules.

A Close Look at Water
An excellent introduction to the structure and properties of water from Northland College.

How Ionic Compounds Dissolve
Animation from Northland College illustrates dissolution of salt in water.

Hydrogen Bonding of Water
An animation by John L.Giannini of St. Olaf College.

Properties of Water
Text and 3-D models created by the Academic Computing Facility at New York University. You'll need to download a 3-D viewer to get the full effect.

The Biology of Water
Part of an online tutorial from the University of Arizona.

The Nature of Water
From the Environment Canada site, an excellent introduction to water's unique properties and its role in living organisms and ecosystems.

Water Science for Schools
A collection of resources from the U.S. Geological Survey. The Water Basics is a good place to start.

pH and Indicators
A concise explanation of the pH scale by Gondar Design. You'll also want to visit their page on acids.

Big Molecules
A set of interactive multiple-choice questions that serve as a tutorial on organic molecules. This is part of The Biology Project at the University of Arizona.

Fire and Spice
This feature article from the General Chemistry Online site describes how the shape of organic molecules is related to our perception of flavor.

Macromolecules of Life
Text and animation by June B. Steinberg.

The Biology of Carbon
Text and 3-D models created by the Academic Computing Facility at New York University. You'll need to download a 3-D viewer to get the full effect.

Biochemistry of Carbohydrates
Part of the Medical Biochemistry site. It's somewhat technical.

What Is Cellulose?
Here's an illustrated answer at General Chemistry Online from Frostburg State University. The site is searchable and filled with information about both organic and inorganic molecules.

Why Beans Give You Gas
The Discovery Channel Online site provides an answer. Turns out it's the carbohydrates.

Biochemistry of Lipids
Part of the Medical Biochemistry site.

Cholesterol
An animated lesson about the structure and function of this best known sterol. It is designed to supplement an biochemistry textbook.

Cyberlipid Center
The "Description" section of this cite describes the various types of lipids and their biological functions.

Sugars and Fats
From The Chemistry of Health, a chapter about the role of sugars and fats in body structure and function.

Amino Acid Basics
An interactive tutorial about the structure of amino acids and their role in proteins.

Biology of Amino Acids
Part of the Medical Biochemistry site. See also Peptides and Proteins on the same site.

Aspartame, a Sweet-Tasting Dipeptide
D. Eric Walters of the Finch University of Health Sciences, Chicago Medical School, explains how this sweetener was discovered and how it is metabolized. If you have the Chime plug-in, check out the link to the Chime-enhanced site.

Proteins Are the Body's Worker Molecules
From an online book about structural biology, an illustrated chapter about the structure and function of proteins.

Proteins and Proteonomics
Multimedia resources from the Rediscovering Biology site, a project of the Annenberg Foundation and the Corporation for Public Broadcasting.

RCSB Protein Data Bank
llustrated information about the structure and function of proteins. Be sure to check out "Molecule of the Month" features.

Does eating turkey make you sleepy?
Role of tryptophan and carbohydrate chemistry.

Discover How Proteins Function
A resource from the Genetic Science Learning Center site provided by the Eccles Institute of Human Genetics at the University of Utah.

Science Friday: Protein Folding
This is a link to a RealAudio file of a 1998 Science Friday discussion of the study of protein folding and the role of protein folding in disease.

Biosphere 2
Center for research, outreach, teaching and life-long learning about Earth

A Big Ball of Life
Biosphere basics from Geography4Kids.com

The encyclopedia of earth
Online encyclopedia with information and links regarding the biosphere.

Atlas of the Biosphere
Website on the biosphere with a maps section and a schematics section. The Maps section contains geographically explicit data broken down into four general categories: Humans, Land Use, Ecosystems, and Water Resources. Follow the menus to reach your dataset of interest. The Schematics section looks at the various resource flows and pools that make up individual Earth systems.

The Earth's Biosphere
Website administered by the University Corporation for Atmospheric Research (UCAR), containing a wealth of information on the biosphere.

Visible Earth: Biosphere
Biosphere basics from Geography4Kids.com

Just One Biosphere
Current, detailed environmental news and information about global warming, renewable energy, conservation, recycling and global environmental issues.

Biosphere: How Life Alters Climate
A discussion of climate changes and interactions among the biosphere's ecosystems.

To Know Ourselves
Information about the Human Genome Project: the goals, tools, and social implications.

A Revolution in Progress: Human Genetics and Medical Research
An online exhibit from the Museum of Medical Research. It covers basic human genetics, cutting-edge technology, and ethical questions.

The Human Genome Project: Exploring Our Molecular Selves
Video, animation, and a downloadable booklet describe how and why the human genome was sequenced. The animation of gene mapping and sequencing is particularly useful.

Gene Therapy - Human Genome Project
Describes gene therapy, how it works, and other items regarding gene therapy.

Cracking the Code of Life
PBS's NOVA provides this site filled with interviews, interactions, and information about the human genome.

Biotechnology Industry Organization—Bioethics
An industry site filled with breaking news and fact sheets about the use of genetic engineering.

American Journal of Bioethics Online
News, book reviews, and informative special features about gene technology and other controversial issues.

Cloned and Genetically-Modified Animals
Article from the Center for Genetics and Society.

The Next Pig Thing
A Mother Jones article about the controversy over genetically engineered "Enviropigs."

Harvest of Fear
A PBS Frontline site about the fight over genetically modified foods.

Jefferson's Blood
DNA evidence suggests that Thomas Jefferson fathered at least one child of the slave Sally Hennings. Learn all about the science, history, and controversy on the PBS Frontline site.

Labor and Delivery
Collection of useful articles and illustrations about labor and delivery from the Discovery Health Channel.

American College of Obstetricians and Gynecologists
A professional organization site that provides informative patient pamphlets and research updates.

Fetal Alcohol Syndrome
Personal stories, photos, a fact sheet, and lots of links to other sites that drive home the risks of drinking while you are pregnant.

March of Dimes
The leading organization dedicated to prevention of birth defects. It is an excellent source of information on how to have a healthy baby.

Thalidomide Victims Association of Canada
Web site of a charitable organization. It provides a good historical account of the use and effects of thalidomide, as well as information about the renewed use of this drug.

Thalidomide
This tutorial by Alex Lingham at Bristol University School of Chemistry covers the chemical structure of thalidomide, its tragic teratogenic effects, and its re-emergence as a drug for leprosy and AIDS.

Windows on the Womb
Illustrated information about prenatal testing and monitoring from PBS's NOVA: Life's Greatest Miracle.

National Institute of Child Health and Development
This government site is filled with information about child development.

Lifeblood
A portion from The Heart: An Online Exploration from the Franklin Institute. This covers the basics.

Molecule of the Month: Serum Albumin
A Protein Data Bank profile of the most plentiful blood protein.

A Summary Study of Blood
This is an article from Micscape, the magazine for amateur microscopists. It's relatively jargon free and includes some nice micrographs of blood cells.

Red Gold: The Epic Story of Blood
A PBS site designed to supplement a television program. It is a beautiful site filled with accessible tests, animation, and graphics.

Molecule of the Month: Hemoglobin
A profile of the most important respiratory pigment is provided by the Protein Data Bank site.

Life Cycle of the Erythrocyte
An informative text page for an Anatomy and Physiology course at Union County College.

Genes and Blood Type
A description of the roles of the components of blood and of human blood types. It is provided by the University of Utah's Genetic Science Learning Center.

About Blood and Cellular Therapies
Information about who donates blood, the most common blood types in the United States, how donated blood is used, and screening for blood-borne diseases. This is on the American Association of Blood Banks site.

The Nobel Prize in Physiology or Medicine 1930
This page on the Nobel Foundation site honors the work of Karl Landsteiner, who won the 1930 prize for the discovery and description of ABO blood types.

Blood Typing Game
Put your knowledge of blood types to work by playing this game on the Nobel Foundation site.

Molecule of the Month: Thrombin
A Protein Data Bank profile of this vital component of the clotting pathway.

Blood Coagulation
This part of the Medical Biochemistry site describes the biochemistry of hemostasis in great detail.

National Heart, Blood, Lung Institute - Blood Diseases and Resources
Information about sickle-cell anemia, blood transfusions, and more from this U.S. government institute.

Sickle Cell Disease Association of America
A site filled with educational and support material, a glossary, and access to the latest research.

Aplastic Anemia Foundation
Aplastic anemias are relatively rare diseases that occur when the bone marrow stops making enough healthy red blood cells. Visit this foundation's site to learn more.

Leukemia Society of America
Home page of a nonprofit foundation dedicated to curing leukemia, lymphoma, Hodgkin's disease, and myeloma. Their educational materials describe these diseases and their treatment in detail.

CancerQuest
A resource site designed to teach the public about the processes that causes cancer, as well as how it is detected and treated.

Oncolink
A searchable source of cancer information provided by the University of Pennsylvania Cancer Center.

American Cancer Society
Another great source of information about cancer.

Cell Biology and Cancer
Multimedia resources from the Rediscovering Biology site, a project of the Annenberg Foundation and the Corporation for Public Broadcasting.

Molecule of the Month: p53 Tumor Suppressor
The Protein Data Bank site describes the structure and function of this important regulatory protein.

National Cancer Institute on Smoking and Cancer
Provides questions and answers regarding smoking and cancer.

Mayo Clinic
Examines cancer and provides useful information.

Medicinenet Colon Cancer Information
Provides multimedia material on colon cancer

Causes and Prevention of Cancer
A document by Bruce Ames, director of the National Institute of Environmental Health Sciences Center. It describes how DNA can be damaged, how this damage can lead to cancer, and what can be done to prevent this from happening.

Chemotherapy and You; A Guide to self-help during Cancer Treatment
National Cancer Institure site provides information about how to cope with chemotherapy.

Treating and Preventing Cancer with Vaccines
National Cancer Institute site provides information about cancer vaccines.

Project Zero: The Project to End Prostate Cancer
A wealth of information about prostate cancer and treatment options.

Skin Cancer Updates
Extensive information is provided on this site, courtesy of the American Academy of Dermatology.

An Introduction to Skin Cancer
A Hawaiian site that will convince you to limit your time in the sun, or at least use a sun block. You can also access relevant news and check on the daily UV forecast for cities throughout the United States.

National Cancer Institute on Colon Cancer
Provides a wealth of information on colon cancer.

The Heart and Circulatory System
A historical account of how we came to understand human circulation and a discussion of the various types of circulatory systems in animals. This is from the Access Excellence site.

Cardiovascular System
Part of a training course developed at Emory University. It is beautifully illustrated.

Heart Information Center
The Texas Heart Institute provides information and interactions that cover the biology of the heart and circulatory system.

The Heart: An Online Exploration
A wonderful online exhibit from the Franklin Institute that covers all aspects of the human circulatory system.

Introduction to Anatomy - Circulatory System & Blood
Lecture notes for a course from the Centre for Human Biology, University of Leeds (UK).

WISC-Online
Animated overview of systemic and pulmonary circulation.

American College of Cardiology
The American College of Cardiology is the major professional organization for cardiologists. Visit this site for the clinical statements and to access the latest information about cardiology research.

Medline Plus High Blood Pressure
A collection of pamphlets, tutorials, and other materials from government agencies medical associations.

American Heart Association
This nonprofit health foundation provides a wealth of information about cardiovascular disease and its treatment.

Vital Signs: Understanding Cardiovascular Disease
An online exhibit from the Howard Hughes Medical Institute.

State-of-the-Art in Artificial Hearts
An Access Excellence interview with cardiothoracic surgeon Mehmet Oz, MD, about advances in artificial hearts.

Lymphatic System
This is part of a training module developed at Emory University and is beautifully illustrated.

Lymph and Immunity
Discussion of the lymphatic system and immunity from Maricopa College faculty pages.

Lymphatic System: Spleen and Other Organs
A section from a Veterinary Histology course at Virginia-Maryland Regional College of Veterinary Medicine.

Henrietta's Dance
From John's Hopkins Magazine, an excellent article about Henrietta Lacks, the importance of HeLa cells, and the ethical questions raised by how the cell line was developed.

Glossary of Genetic Terms
A wonderful illustrated dictionary with audio pronunciations, from the National Human Genome Research Institute.

The Cell Cycle & Mitosis Tutorial
This exercise is designed to introduce you to the events that occur in the cell cycle and the process of mitosis. This is part of The Biology Project, an interactive resource for learning biology at the University of Arizona.

Mitosis
Interactive Mitosis Tutorial

Online Onion Root Tips
An online simulation of an experiment in which the cells of an onion root tip are examined to determine the time spent in different parts of the cell cycle. This is also part of The Biology Project from the University of Arizona.

Animated Cell Cycle
From the Cells Alive site, a looped animation shows the basic cycle and allows you to see what happens at checkpoints.

The 'Immortal' Story Of One Woman's Cells
In The Immortal Life of Henrietta Lacks, author Rebecca Skloot tells the story of Henrietta Lacks' 'immortal cells'—cells taken from a tumor on her cervix and kept alive to multiply in laboratories around the world—and how Lacks' children discovered their connection to the cells.

Membrane Structure
A page from a cell biology site by Dr. Gwen Childs at the University of Arkansas.

Gallery of Membrane Proteins
Profiles of the roles of some interesting membrane proteins from Bill Wimley at Tulane University Medical Center.

Cell Membrane Tutorial
From the Biology Project site at the University of Arizona. A series of multiple choice questions serve as a tutorial that covers membrane structure and function.

The Fluid-Mosaic Membrane Model as a Scientific Fact
This page explains the model and describes the studies that led to its acceptance.

New Clues to How RNA Exits the Nucleus
A research report from the Howard Hughes Medical Institute.

The Nucleus
A guide from the Cell Biology Program at the University of Texas Medical Branch.

Golgi Complex: Structure and Function
Information from the Cell Biology Program at the University of Texas Medical Branch.

Endoplasmic Reticulum: Structure and Function
A page from a cell biology site by Dr. Gwen Childs at the University of Arkansas.

How the Scanning Electron Microscope Works
A presentation from the Boston Museum of Science.

How Lysosomes and Peroxisomes Are Produced
Information from the Cell Biology Program at the University of Texas Medical Branch.

Mitochondrion Reconstructed by Electron Tomography
This page links you to QuickTime movies demonstrating the process of electron tomography and the results from three-dimensional reconstruction of a mitochondrion. It is provided by the National Center for Microscopy and Imaging Research.

Mitochondria: Architecture Dictates Function
A page from a cell biology site by Dr. Gwen Childs at the University of Arkansas.

Mitochondria Research Society
The Mitochondria Research Society (MRS) is a nonprofit international organization dedicated to promoting research on the basic science of mitochondria and mitochondrial disease.

The Secrets of a Cell's Skeleton at 8-Angstrom Resolution
A report about how Berkeley Lab researchers are using electron microscopy to study cytoskeletal components.

Cytoskeleton Tutorial
From the University of Arizona. Covers components, internal motility, external motility, and a quiz.

Microtubules
Structure and function of microtubules.

Keeping Warm: Evolution to the Rescue
Mitochondria don't just make ATP, they generate heat. How much heat varies and may be an adaptation to life in a cool climate.

Inside A Cell
An interactive introduction to the components of an animal cell from the University of Utah's Genetic Science Learning Center.

Inside the Cell
An excellent educational resource provided by the National Institute of General Medical Sciences. It includes drawings, micrographs, and hypertext glossary terms.

Cell Basics
The Cell: Down to Basics

What Is a Cell?
You'll find the answer to this question and much more in this primer from the National Center for Biotechnology.

Cells Alive
This site deals with all types of cells. Rich in graphics and video, the site also has links to other cellular and microbiology information.

CancerQuest: Cell Structure
This is part of an educational site about cancer. It provides a jargon-free introduction to a human cell and its components.

Virtual Cell Animation Collection
A collection of cell animations developed to introduce students to new concepts in cellular processes.

Prokaryotes, Eukaryotes, & Viruses Tutorial
An illustrated tutorial from the University of Arizona. It covers the differences between these groups and the basic structure of each.

Structure and Function of Organelles
Information from the MIT Biology HyperTextBook.

The Micropolitan Museum
A beautiful collection of micrographs arranged as a virtual museum. It is part of the Microscopy-UK site.

Dennis Kunkel, Microscopy - Education
Microscopist Dennis Kunkel provides a wonderful education section filled with beautiful micrographs. You can also search his site for micrographs of particular cell organelles.

Microscopy
Provides basic information on the most commom microscopy techniques.

Cell Biology Animation
Provides animations of key biological processes, cell function overview and its anatomy, concept of gene expression as well as principle of evolution.

Cystic Fibrosis
Information from the Merck-Manual Home Edition.

CFTR - cystic fibrosis transmembrane conductance regulator
NIH information about the CFTR gene and cystic fibrosis

Cystic Fibrosis Foundation
Visit this site to learn more about cystic fibrosis and the attempts to develop a treatment for this disease.

Glossary of Genetic Terms
A wonderful illustrated dictionary with audio pronunciations, from the National Human Genome Research Institute.

Karyotyping Activity
A simulation of human karyotyping using digital images of chromosomes from actual human genetic studies. It is part of The Biology Project at the University of Arizona.

Human Karyotypes for Teaching
A resource provided by ZooWeb and the Wisconsin State Laboratory of Hygiene. It includes normal male and female karyotypes as well as karyotypes of individuals with Turner's syndrome and with various trisomies.

National Down Syndrome Society—Welcome to NDSS
Detailed information about Down Syndrome

BRCA1 and BRCA2: Cancer Risk and Genetic Testing - National Cancer Institute
BRCA1 and BRCA2: Cancer Risk and Genetic Testing

BRCA gene test for breast cancer - MayoClinic.com
BRCA gene test for breast cancer

NCBI Human Genome Resources
Wondering what genes are on chromosome 18? Visit this site to "browse your genome" and find out.

New Methods in Karyotyping
Students at the University of Arizona created this online presentation about spectral karyotyping.

What Can Our Chromosomes Tell Us?
A page from the Genetic Science Learning Center from the University of Utah and the Utah Museum of Natural History.

The Meaning of Sex, Genes, and Gender
From the Howard Hughes Medical Institute BioInteractive site, lectures, animation, and articles about the evolution of the Y chromosome and human sex determination.

NOVA: How Sex Is Determined
This interaction allows you to follow the development of male and female embryos. It's part of PBS's NOVA: Life's Greatest Miracle site.

SRY: Sex determination—Genes and Disease—NCBI Bookshelf
Analysis of individuals has revealed some of the molecules involved in sex determination, including one called SRY

Klinefelter Syndrome Causes, Symptoms, Diagnosis, and Prognosis
Information about Klinefelter's Syndrome

Klinefelter's Syndrome: MedlinePlus
NIH website focused on Klinefelter's Syndrome

PBS: Cnidarians
Learn some interesting facts about cnidarians and watch videos of cnidarians in action. Click on "Going Deeper" to watch a video of the discovery of a new species of jellyfish

Cnidarian Basics
An introduction to cnidarians with simple figures and a look at cnidarian morphology.

UC Berkeley: Intro to Cnidarians
UC Berkeley's biology website on cnidarians. Includes information about cnidarians in the fossil record, life history and ecology, systematics, and morphology.

Jelly fish: links, info, and photos
An informative website on jellyfish. Includes a look at the rise of jellyfish in oceans, a gallery of jellyfish, and an up to date list of articles on jellyfish

Coral reef formation
Learn about the three stages of coral reefs, fringing, barrier and atoll, and how each is formed.

NOAA's Coral Reef Information System (CoRIS) - What are Coral Reefs?
Discussion of coral reefs and the phylum Cnidaria

Oceanic Research Group: Echinoderms
Introduction to echinoderms, their vascular system, habitat and other characteristics. Includes pictures of sea stars, urchins, sea cucumbers, and feather stars.

United States Geological Survey: Sea Lamprey in the Great Lakes
A look at the lamprey's invasion in the Great Lakes. Learn about how their invasion was ecologically damaging and what's been done to control their population.

UC Berkeley: Introduction to the chondrichthyes
UC Berkeley's biology website on chrondrichthyes (cartilaginous fish). Includes information about chondrichthyes in the fossil record, life history and ecology, systematics, and morphology.

BBC Animals
Find your favourite animals, where and how they live, the latest news about them and who's filming them right now.

Declining Amphibian Population Task Force
DAPTF's mission is to determine the extant of amphibians' decline and to promote means by which this decline can be stopped. Learn about the decline of amphibians, the destruction of their habitat and why they matter.

All About Reptiles
A short introduction to reptiles with photo galleries of snakes and lizards. Browse through the up-to-date list of articles about reptiles to learn more.

The Life of Mammals
David Attenborough presents a wildlife series devoted to mammals. Includes highlights, webcams, quizzes and video clips.

Your Digestive System and How It Works
Information from the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health.

Human Anatomy Online: Digestive System
An interactive, multimedia introduction to the human digestive system.

Fundamental Physiology and Anatomy of the Digestive System
This section from the Pathophysiology of the Digestive System hypertextbook provides a good overview.

Digestive System
This is part of a training module developed at Emory University and is beautifully illustrated.

Running through the Human Digestive System
An excerpt from the book Anatomy and Physiology for Dummies. It?s a good overview of the digestive process.

The American Dental Association
This professional organization provides basic information as well as research reports.

Pregastric Digestion
Information about taste, saliva, chewing, and the function of the esophagus from the Pathophysiology of the Digestive System hypertextbook.

Physiology of Taste
A jargon-free explanation by Michael Berry.

Sympathetic nervous control of gastric motility
Sympathetic nervous control of gastric motility and interaction with vagal activity

Irritable Bowel Syndrome
Information concerning irritable bowel syndrome from NIH

Irritable bowel syndrome - MayoClinic.com
Information concerning irritable bowel syndrome from Mayo Clinic

Research in the News: Ulcers
This page from the NIH Education site describes how researchers established the role of bacterial infection in pyloric ulcers.

Small Intestine
More from Pathophysiology of the Digestive System hypertextbook.

Molecule of the Month: Trypsin
Trypsin carries out the tricky task of digesting dietary proteins. This Protein Data Bank profile describes trypsin's structure and explains why it doesn't digest your intestinal lining as well.

Fats and Ols in Human Nutrition
This report covers the metabolic role of fats and oils, as well as their digestion and absorption. It is provided by the Food and Agriculture Organization of the United Nations and the World Health Organization.

The Liver: Introduction and Index
A section from thePathophysiology of the Digestive System hypertextbook; provided by Colorado State University.

The Large Intestine
More from Pathophysiology of the Digestive System hypertextbook.

American Society for Gastrointestinal Endoscopy
Provides information and services related to endoscopy

Control of Digestive System Function
This section of the Pathophysiology of the Digestive System hypertextbook covers the nerves that innervate the digestive system and control of gastric motility. See also The Stomach.

GERD (Gastroesophageal Reflux Disease)
Contains information about GERD (acid reflux)

Morphometry of myenteric neurons in stomach
PubMed information about stomach neurons

Biochemistry of Nucleic Acids
Part of the Medical Biochemistry site.

The DNA Molecule Is Shaped Like a Twisted Ladder
A segment from "DNA from the Beginning," a multimedia-rich resource from the Dolan DNA Learning Center at Cold Spring Harbor Laboratory.

The Molecules of Life
An interactive document provided by the Laboratory of Molecular Biophysics at the University of Oxford. It describes the structure and function of DNA and proteins.

Molecule of the Month: Transfer RNA
This illustrated "Molecule of the Month" feature on the Protein Data Bank site describes the structure and function of transfer RNA.

Molecule of the Month: DNA
An illustrated description of the structure and function of DNA, from the Protein Data Bank Web site.

The Structure of the DNA Molecule
From Access Excellence, this page gives a brief history of the experiments that clarified the importance and structure of DNA. For a detailed description of the Hershey-Chase experiments, visit Experiments that Inspire on the same site.

DNA and Mutations
Understanding DNA and mutations from UC Berkeley

DNA Structure Tutorial
This is an interactive page about DNA. You can spin a molecule of DNA, identify its components, and make it replicate. You'll need to have the Chime plug-in, which is available via a link from the site.

The Secret of Life
From PBS, a supplement to a television show about the discovery of DNA. It includes video of an interview with James Watson.

DNA Interactive
The Howard Hughes Medical Center provides animation of DNA and interviews with the scientists who study its structure and function.

Composition of Life
From the NY Times, a Flash animation about of the role of DNA.

DNA Anatomy
A beautiful tutorial.

Introduction to DNA Structure
Lots of graphics illustrate the major structural features of DNA. The material is provided by the Biology Learning Center at the University of Arizona.

TIME 100: James Watson & Francis Crick
The TIME 100 profile of Watson and Crick

DNA Structure and Function
Excellent discussion of DNA structure and function, with additional links

Center for Cancer Research: replication and cancer
A study that looks at checkpoints in the cell cycle that respond to DNA damage and the inability of cancerous cells to respond to these cues.

DNA Polymerase and non-natural DNA
Looks at the new methods scientists have devised for stitching together artificial DNA parts. Learn about super DNA that's made up of non-natural bases and has potential use in medical and technological applications.

DNA Replication
Contains abundant information and links regarding DNA replication

A Science Odyssey: You Try It: DNA Workshop
PBS DNA replication workshop

Cell Biology Animation by John Kyrk
A detailed animation of DNA replication that allows you to go through the steps at your own pace.

Meselson and Stahl: The art of DNA replication
The story of Meselson and Stahl's partnership. Learn about the two scientists responsible for what's been called the most beautiful experiment in biology.

DNA Replication - St. Olaf College—A private liberal arts college
DNA replication animation

DNA Replication Fork - Harvard Home
Animation of a DNA replication fork

Synthetic Opiates and Opiods
This Museum of Medical Research exhibit describes how and why researchers created synthetic opiates.

Addiction's Path
Information from the Society for Neuroscience.

Why Can't the Brain Shake Cocaine
A research review from The Scientist.

The Science of Addiction
The Science of Addiction from the National Institute on Drug Abuse (NIDA)

Alcohol News & Addiction News & Illegal Drugs News
Contains numerous links to information regarding drugs and addiction from the Medical News Today site.

National Institute on Drug Abuse
This government Web site provides up-to-the minute information about drug abuse and addiction.

Addiction - A Whole New View
What we know about addiction, where the cravings 'live' in the brain and mind.

The Limits of Love
Research with mice suggests that cocaine addiction interferes with hormones involved in maternal behavior.

Ohio State: Oldest complex organic molecules isolated
An article about the discovery of the oldest complex organic molecules inside fossils.

Carnegie Institution: Learning to Live With Oxygen
Scientists discovered evidence that microbes adapted to living with oxygen 2.71 billion years ago.

Early Oxygen
Discussion of banded iron formations and oxygen in the earth's atmosphere

Caltech: Early oceans
New evidence found in the oil fields of Oman explains the evolution of single-celled organisms to multicellular organisms.

National Geographic: Early life, pictures, timeline
A look at modern landscapes could give us glimpses of what early earth may have looked like. Included is a slide show of some modern landscapes and videos of what primordial earth may have looked like.

2-Billion-Year-Old 'Window' to Planet's Past Found
Banded rock layers hint at past climate conditions

Earth's First 3.7 billion years
Lecture discussing the early history of earth

Ecosystems
Ecosystems and biomes on our planet.

Ecosystems, Biomes, and Habitats
Living Things: Habitats & Ecosystems

NatureWorks: Ecosystems
Major parts of the ecosystem

Endangered Ecosystems
Teaching activities and teaching resources from Scholastic

Scientific Facts on Ecosystem Change
Discusses how ecosystems change

Ecosystems – US Environmental Protection Agency
EPA website with numerous links discussing ecosystems

Millennium Ecosystem Assessment
The Millennium Ecosystem Assessment assessed the consequences of ecosystem change for human well-being.

Nature Conservancy News Room – The Millennium Ecosystem Assessment
Nature Conservancy press release regarding the Millennium Ecosystem Assessment, with numerous links

Biomes and Ecosystems
Multimedia tour of biomes and ecosystems

Environmental Biology Sequence – Ecosystems
Marietta College webpage discussing environmental biology and ecosystems

Endocrine System
This is part of a training program developed at Emory University. Use the links at the top to delve deeper into the subject. The hypertext terms link to definitions.

Pathophysiology of the Endocrine System
Visit this site for information about the mechanisms of hormone action, as well as specific glands. This is part of a biomedical hypertextbook from Colorado State University.

Endocrine System
This section of Human Anatomy Online describes the major endocrine glands and their functions. It provides a good introductory overview.

The Endocrine Society
Visit this professional society site to learn about the latest advances in endocrinology.

Molecule of the Month: Estrogen Receptor
Estrogen is a steroid hormone and this Protein Data Bank article describes how the hormone's effects are mediated by the receptor inside the nucleus.

Martin Rodbell: Discovering How Cells Respond to Signals
An online exhibit from NIH's Museum of Medical Research. Rodbell discovered that the messages from peptide hormones are transduced.

Steroid Hormones and Receptors
This and Receptors for Peptide Hormones are two sections on the Medical Biochemistry site.

Hypothalamus and Pituitary Gland
A section from the Pathophysiology of the Endocrine System site.

Molecule of the Month: Growth Hormone
Visit this site to learn about the structure of this key hormone and how it interacts with receptors on cell membranes.

Acromegaly
Extensive information about this pituitary disorder in which excess somatotropin is produced. It is provided by the National Institute of Diabetes and Digestive and Kidney Disease.

Table of Vertebrate Hormones
The structure and function of the various hormones are covered in great detail on this part of the Medical Biochemistry site.

Stress System Malfunction Could Lead to Serious Life-Threatening Disease
This NIH backgrounder explains how stress can alter normal hormonal feedback systems.

Adrenal fatigue: Is there such a thing? – MayoClinic.com
Mayo Clinic discussion of adrenal fatigue syndrome

NRDC: Endocrine Disruptors
National Resources Defense Council discussion of endocrine disruptors

American Thyroid Association
This site provides patient information, guidelines for physicians, and a research section about thyroid disorders.

Thyroid Disorders
Comprehensive and up-to-date information about hormone disorders from The Diabetes and Hormone Center of the Pacific.

Steroids of the Adrenal Cortex
This and Regulation of Adrenal Steroid Synthesis are part of the Medical Biochemistry site.

National Adrenal Diseases Foundation
This nonprofit organization provides information about diseases of the adrenal glands and the latest research into their treatment.

NIDDK Health Information
The National Institute of Diabetes and Digestive and Kidney Diseases provides information about diabetes and many other endocrine disorders.

Is diabetes a public-health disorder?
Article from US National Library of Medicine magazine.

American Diabetes Association
This nonprofit health organization provides diabetes research, information, and advocacy.

The Nobel Prize in Physiology or Medicine 1986
This page on the Nobel Institute Site honors Stanley Cohen and Rita Levi-Montalcini for their discoveries of growth factors. The press release summarizes their research.

Melatonin
A tutorial that includes a 3D model of the molecule (you'll need the Chime plug-in). It was created by Salinthip Thipayang at the Imperial College, London, U.K.

Hormone Control: The Hypothalamus
A page from the Brain Tours on the Psycheducation.org site.

Environmental Agents: Endocrine Disruptors
NIEHS discussion of endocrine disruptors

Estrogen Dominance
Discussion of estrogen dominance

Panic Attacks and Biochemistry: The HPA Axis (what?)
Article on the HPA axis and panic attacks

Evidence Supporting Biological Evolution
A chapter from the National Academy of Sciences online version of "Evolution and Creationism."

Fossil Horses in Hyperspace
A terrific virtual exhibit about the fossil record of horses, from the Florida Museum.

Evolution and the Fossil Record
An extensive online brochure from the American Geological Institute.

Vertebrate Flight Exhibit
An exhibit from the University of California Berkeley Museum of Paleontology. It provides an example of convergent evolution among the pterosaurs (extinct reptiles), birds, and bats.

The Beast of Bodin Moor
An interactive exercise in which you must use comparative anatomy to determine the identity of a mysterious beast.

The Embryonic Zoo
From this page, you can download and compare videos of "morphing" pig, human, chick, and fish embryos. They are from the NOVA special "Odyssey of Life."

Evolution: Library: Whale Evolution
PBS website on whale evolution

Evidence for Evolution: the Origin of Whales
The story of the origin of whales is one of evolution's most fascinating tales and one of the best examples scientists have of natural selection.

Evolution and Phylogenetics
Text, animation, and images describe the molecular approach to understanding evolutionary relationships. This resource was created by the Annenberg Foundation and the Corporation for Public Broadcasting.

Malaria, Algae, Amoeba, and You: Unraveling Eukaryotic Relationships
An article from Actionbioscience.org about how new discoveries are altering our understanding of the relationships between eukaryotes.

Earth on the Edge
Bill Moyers and PBS take a look at the condition of the five ecosystems on which all life most heavily depends: freshwater, agriculture, forests, grasslands, and coastal ecosystems.

The Sixth Extinction
An article by Niles Eldredge, Ph.D., on the Actionbioscience.org site.

PBS Evolution Library
PBS website containing numerous links on evolution

A History of Evolutionary Thought
Profiles of scientists and thinkers who contributed to our understanding of evolution.

A Chronology of Evolution
From Access Excellence, a useful timeline of the discoveries that led to the modern understanding of evolution.

The Darwin-Wallace 1858 Paper
The paper and other interesting related documents are provided by the University of Maryland.

Ernst Mayr: Genetics and Speciation
MAYR, GENETICS, AND SPECIATION BEFORE 1950

Songbird Shows How Evolution Works
A BBC News feature about speciation in warblers.

American Dietetic Association
A wealth of information about food and nutrition, as well as career advice for potential dieticians.

USDA Food and Nutrition Information
Visit this U.S. government site for dietary guidelines, booklets about food pyramids, and lots of additional public education materials organized by topic.

Vegetarian Nutrition
A collection of links compiled by the USDA.

International Food Policy Research Institute
IFPRI's 2020 vision to provide sufficient and nutritious food to all people.

UN Food and Agriculture Organization
A smorgasbord of information about the world food situation. The site includes documents, databases, and news.

Malnutrition
A look at the physiology and effects of malnutrition by pediatrician; onthe e-Medicine site.

Unraveling the Enigma of Vitamin D
From the National Academy of Sciences, the story of how scientists learned to fight rickets and came to understand the role of vitamin D in controlling the body's calcium level.

The Killer in Your Yard
The Audubon Magazine guide to home pesticide use.

Vitamins and Minerals
A collection of links compiled by the USDA.

The Biology of Obesity
From the part of the Howard Hughes Medical Institute site you can link to a RealVideo presentation about obesity by Dr. Jeffrey Friedman, who studies the role of lepin.

Obesity Could Break Your Heart
A Why Files feature explains the health risks of obesity.

Burn Rate
Learn how many calories you'll burn in a session of archery, running, or other activity. The calculator is provided by the Discovery Health Channel.

Health Weight Planner (BMI calculator)
A tool from the Mayo Clinic for those who wish to lose weight.

U.S. EPA Pesticide Programs
This U.S. government site has information for pest control professionals and the general public. The "Concerned Citizen" section is a good place to start.

Fruit Facts
An list of fruits and their properties. Simply click on the fruit about which you'd like to learn.

Major types of fruits
A breakdown of the different types of fruits and their characteristics. Includes accompanying drawings.

USDA: How to buy fresh fruits
The USDA's guide to buying fresh fruit. Discusses Wholesomeness, nutritive value, labeling and quality. Includes advice for different fruit types.

UC Berkeley: Into to Fungi
UC Berkeley's biology website on fungi. Includes information about fungi in the fossil record, life history and ecology, systematics, and morphology.

An overview of fungi and their uses
A look at the different types of fungi with plenty of accompanying pictures. Also includes information about healing mushrooms, hallucinogenic mushrooms, and the truffle.

Truffles: Treasure in the ground
Truffles, the delicious but expensive mushroom. Learn how truffle farmers find these treasures.

Fungi Perfecti: a biography of Paul Stamets
Paul Stamets has been a dedicated mycologist for over thirty years

Edible Mushrooms
Mushroom Council's website promoting edible fungi and their nutritional properties. Click on "Care and Handling" to learn about safety measures for handling mushrooms.

Fungal Infections
Information on fungal infections, symptoms, diagnosis, and clinical trials. Includes the latest news on fungal infections.

Variations to Mendel's First Law of Genetics
Information for a class in Intermediate Genetics at North Dakota State University in Fargo.

Sickle Cell Anemia
Complete information on Sickle Cell Anemia from the National Library of Medicine.

Blood Types Tutorial
A tutorial from The Biology Project at the University of Arizona.

Pleiotropic Effects and Lethal Genes
Information from Intermediate Genetics at North Dakota State University in Fargo.

Quantitative Genetics
Information about continuous variation and its causes, from Intermediate Genetics at North Dakota State University in Fargo.

Summary of gene regulation in Eukaryotes
Discover how DNA transcription gets regulated. This site covers introns, exons, promoters, and includes helpful figures.

Gene control
This article highlights research into the specific triggers of DNA repair. This research might lead to drugs that could boost DNA repair and help thwart cancer.

BBC news: Rethinking Junk DNA
A report on how "junk" DNA, or DNA that doesn't code for anything, might actually serve a very important function.

Dartmouth College: A video demonstration of how the lac operon works
Watch a step-by-step video demonstration of the Lactose operon works in an E-coli cell.

HIV medicine inhibits protease
A look at HIV's resistance to drugs that inhibit protease. A new study that looks at how the virus' develops resistance to protease inhibitors may help in the fight for better HIV drugs.

The University of Utah's overview of gene therapy with interactive animations
The University of Utah's overview of gene therapy with interactive animations. See gene therapy in action in a case study of Cystic Fibrosis.

The Glimmering Promise of Gene Therapy
An article on gene therapy's beginnings and its rise in prominence as a potential treatment for the most horrendous human diseases.

MendelWeb
Mendel's paper "Experiments in Plant Hybridization" is now available on the Web. (It is in English, though the original German version is available as well.) MendelWeb also has some discussion questions and hopes to have homework assignments based on the classic paper.

Glossary of Genetic Terms
A wonderful illustrated dictionary with audio pronunciations, from the National Human Genome Research Institute.

Mendel's First Law
Information for a class in Intermediate Genetics at North Dakota State University in Fargo.

Punnett Squares
An interactive interface to figure out genetic probabilities using Punnett squares

Mendel's Second Law
Information for a class in Intermediate Genetics at North Dakota State University in Fargo.

Dihybrid Cross Problem Set
Interactive problems that serve as a tutorial. This is part of The Biology Project from the University of Arizona.

Linkage
Illustrated notes from a U.K. medical school course.

Understanding Gene Testing
A U.S. Department of Health and Human Services publication that explains basic genetics, genetic testing, the link between genes and cancer, etc.

Beyond Discovery: The Path from Research to Human Benefit
From the National Academy of Science's site, an excellent series of articles about gene testing.

Mendelian Laws Apply to Human Beings
Hemophilia is used to introduce the concept of pedigrees and human genetic analysis in this portion of the DNA From the Beginning site. It includes animation and video interviews.

Human Chromosome Launchpad
A source of links to genetic information organized by chromosome. It's provided by Oakridge National Laboratory.

Color Blindness Problem Set
A problem set is based on a question received from a woman who is red-green color blind. She wanted to know how she inherited her color blindness. This is part of the Human Biology section of The Biology Project.

Human Gene Mutation Database
This searchable database shows which genes have been linked to a given disease and provides references to the journal in which each link was first reported.

Online Mendelian Inheritance in Man
Though this huge searchable database is primarily used by researchers, you can use it to find descriptions and references for any human disease with a known genetic link.

Phenylketonuria Home Page
A resource for those interested in the screening and treatment of PKU. This autosomal recessive metabolic disorder can lead to mental retardation if it is not caught early, but it is treatable and is commonly screened for at birth. While you are there, check out "The Discovery of PKU" for the fascinating story of PKU's discovery.

National Organization for Albinism and Hyperpigmentation
Here's a lot of information about human albinism, an autosomal recessive disorder. Their "report" section is particularly useful.

Huntington's Disease Society of America
National nonprofit organization provides information about this fatal autosomal dominant disorder that manifests itself in middle age.

A Pedigree of Hemophilia in the Royal Families of Europe
Detailed explanation of hemophilia based on the pedigree analysis of the Royal family.

Genetic Pathology Gallery
This site shows karyotypes of various human chromosome abnormalities.

Chromosome Deletion Outreach
A set of notes by a support group for families dealing with chromosome disorders. It provides excellent illustrated descriptions of chromosomes and the abnormalities that can arise.

Fragile X
Information from the Society for Neuroscience about how Fragile X affects the nervous system.

FRAXA Research Foundation
A page devoted to Fragile X syndrome, a duplication that is the leading cause of inherited mental retardation. There is a photo gallery of children with the syndrome, as well as information on its cause and on the diagnostic tests and treatment that are currently available.

National Down Syndrome Society
The NDSS supports research and works to increase public awareness about Down Syndrome. The site provides basic educational material, research reports, and referral services.

Turner Syndrome Society
TSS is an non-profit organization founded to encourage medical research, the dissemination of state-of-the-art Turner Syndrome information, and social support services to individuals, families, physicians, and the general public.

Restriction Enzymes Background Paper
An Access Excellence page that covers these amazing molecular scissors in great detail.

Molecule of the Month: Restriction Enzymes
Illustrated information about the structure and function of restriction enzymes, from the Protein Data Bank site.

Molecular Genetics: Piecing It Together
A primer from the National Center for Biotechnology Information. It covers DNA isolation, cloning, PCR, sequencing, and more.

What the Heck Is PCR?
A simple explanation aimed at the public. It is one of a series of articles by John Brown at the University of Kansas.

Polymerase Chain Reaction
PCR basics from the Dolan DNA Learning Center.

Current Sequencing Technologies
Information from the Primer on Molecular Genetics.

Gel Electrophoresis
Gel electrophoresis is used to detect differences in the length of DNA molecules. This interactive animation on the Genetic Science Learning Center site shows you how its done.

Ohio State University: Gymnosperms
An introduction to gymnosperms: ginkgoes, cycads and pines

The Gymnosperm Database
A source of information on gymnosperms. Click on site map and choose between cycads, ginkgoes, conifers, and gnetophytes.

UC Berkeley: Introduction to the Cycads
UC Berkeley's biology website on cycads. Includes information about cycads during the Jurassic Period, their life history and ecology, systematics, and morphology.

Palm and Cycad Association of Australia
Articles on cycads and links for different genera of cycads.

Gymnosperms.org
A list of gnetophore families and genera. Browse the pictures to see what the different genera look like.

Herbs at a glance: ginkgoes
An introduction to ginkgoes and its medicinal use.

Physiological Homeostasis
A series of pages designed to explain the concept to a layperson. This is part of the Biology Online site.

Of Pools, Balance, Equilibria, and Homeostasis
Introductory section for an online physiology course from the University of Vermont.

Cleavage--How Are the Building Blocks of the Embryo Produced?
This is one of the many informative articles from the University of Calgary's Dynamic Development.

From Sperm and Egg to Embryo
Detailed information about fertilization and development from the University of Calgary's Dynamic Development.

The Thin Blue Line
An online exhibit from the National Insitute of Health about the history of pregnancy testing.

HCG Pregnancy Test
An animation created to accompany an immunology textbook illustrates how antibodies are used to test for a hormone synthesized during pregnancy.

The Visible Embryo
A media-rich tutorial about the first four weeks of human development, from University of California at San Francisco.

Embryo Development Overview
This site from the University of Pennsylvania Health System lets you view human development from conception to week 38, either as a series of still images, or as a movie. It also provides information about what characterizes each stage and links to pages about eye and ear development.

Embryo Images
Scanning EM images and diagrams of normal and abnormal development in mice and humans.

Pregnancy Week by Week
A section of the Pregnancy.about.com site.

Medline Plus Fetal Development
A page from the MEDLINEplus Medical Encyclopedia. It describes development week by week. Hypertext links go to additional information and to graphics.

Cloning Conundrum
The Why Files site tackles the issue of human cloning.

The Roots of Aging
An article from Life Extension magazine about a study of aging and the latest research reports.

Does Chromosome 4 Hold the Secret to Human Longevity?
A research report from the Howard Hughes Medical Institute.

National Institute on Aging
Information includes many online pamphlets about the causes and health effects of aging.

Beyond the Myths of Aging
An article from the Harvard Public Health Review about how life expectancy and quality of life can affect life expectancy and quality of life.

North American Menopause Society
Web site of a scientific nonprofit organization devoted to promoting women's health during midlife and beyond through an understanding of menopause.

Secret Life of the Brain: Aging Brain
Part of the PBS site for the series "Secrets of the Brain." This episode covers Alzheimer's disease and normal aging.

Becoming Human
News, multimedia, and more provide a journey through the story of human evolution.

Rediscovering Biology: Human Evolution
Multimedia resources from the Rediscovering Biology site, a project of the Annenberg Foundation and the Corporation for Public Broadcasting.

Human Evolution
A chapter from the National Academy of Sciences online version of "Evolution and Creationism."

Human Evolution: Fossil Evidence in 3D
Rotatable images of human fossils, from the University of California, Santa Barbara.

Smithsonian Institution Human Origins Program
Information about ongoing research, a "tour" of human ancestors, and an "ask-a-researcher" section.

Origins of Modern Humans
Interview with evolutionary biologist Douglas J. Futuyma.

Globio
Ongoing programme to map the past, current and future impacts of human activities on the biosphere

Climate Change
Information on climate change from the U.S. EPA

Global Warming: Early Warning Signs
Map illustrates the local consequences of global warming.

Human Anatomy Online: Male Reproductive System
Mouse over the parts of the male reproductive system to learn their functions.

Male Reproductive System
This is part of a training module developed at Emory University and is beautifully illustrated.

Images of the Sperm—Van Leeuwenhoek and Homunculi
Visit this page for a historical perspective on our understanding of sperm and spermatogenesis.

Testicular Transplant First
A 2002 BBC news article.

Project Aware
This web site provides information about menopause symptoms and the various therapies that can alleviate them.

Human Anatomy Online: Female Reproductive Function
Mouse over the parts of the female reproductive system for brief descriptions of their functions.

Female Reproductive System
This is part of a training module developed at Emory University and is beautifully illustrated.

The Ovarian and Uterine Cycles
Animations show how oocytes develop and the cyclic changes in the uterus.

Fertilization
Provides information on the events that lead to fertilization.

Causes of painful intercourse
Information on painful intercourse

Anatomy of the Penis, Mechanics of Intercourse
Detailed explanation on mechanics of intercourse in men with illustrations.

FDA Birth Control Guide
Descriptions of birth control methods and failure rates from clinical trials are provided by the U.S. Food and Drug Administration.

Birth Control Problem Set
A tutorial quiz from The Biology Project at the University of Arizona.

A Patient's Guide to Male Infertility
This area of the Atlanta Reproductive Health Center's site provides a detailed description of male reproductive physiology, including the role of hormones. (See the section entitled "Male Reproductive Physiology," below the section about assessment of male fertility.)

Science Friday - Fertility Treatments/Multiple Births
Visit this page to download a RealAudio file of a National Public Radio discussion about the science and ethics of new reproduction technologies.

Resolve: The National Infertility Association
An organization that provides education and advocacy for people faced with infertility.

Making Babies
This PBS Frontline site includes interviews with fertility experts and video of two high-tech procedures.

The Truth about Impotence
A PBS NOVA site provides print information about this common malfunction of the male reproductive system and the various treatment options.

Immunization, Vaccines and Biologicals
The World Health Organization provides this comprehensive resource.

Edward Jenner and the Discovery of Vaccination
An exhibit from the University of South Carolina.

Molecule of the Month: Lysozyme
Illustrated information about lysozyme structure and function, from the Protein Data Bank Web site.

Innate (Nonspecific) Immunity
A section from Microbiology and Immunology Online from the University of South Carolina Medical Center.

Complement
A section from Microbiology and Immunology Online from the University of South Carolina Medical Center.

Anatomy of a Splinter
A multimedia explanation of inflammatory response from the Cells Alive site.

Defending the Body from Within
Part of the BioInteractive Museum from the Howard Hughes Medical Institute.

Understanding the Immune System
Patient information from the National Cancer Institute.

Molecule of the Month: Antibodies
Illustrated information about antibody structure and function, from the Protein Data Bank Web site.

How Lymphocytes Produce Antibody
From the Cells Alive site, this page includes a micrograph, text explanation, and animation of antibody production.

What the Heck Is an Antibody?
Here you'll find an accessible answer.

Understanding the Immune System
Information from the National Cancer Institute on the Immune System.

The Immune System
Introductory overview from the National Institute of Allergy and Infectious Diseases.

What the Heck Is an MHC Molecule?
A straightforward text introduction to the role of MHC molecules and the meaning of histocompatibility.

Immunoglobulins: Structure and Function
A section from Microbiology and Immunology Online from the University of South Carolina Medical Center.

Cloning an Army of T Cells for Immune Defense
An highly technical animation from the Howard Hughes Medical Institute.

Cellular Immunity
Cellular immunity animation

The Nobel Prize in Physiology or Medicine 1996
This page on the Nobel Institute site honors Peter C. Doherty and Rolf M. Zinkernagel, who showed that T-cells respond to a combination of MHC markers and foreign antigen.

The Cytotoxic T Lymphocyte
This page on the Cells Alive site provides a great movie of a cytotoxic T lymphocyte attacking and killing a virus-infected cell. See also Apoptosis: Dance of Death on the same site.

The Vaccine Page
News about vaccines and an annotated database of vaccine resources on the Internet.

Immunization
A section from Microbiology and Immunology Online from the University of South Carolina Medical Center.

Influenza Vaccine
The American Academy of Family Physicians provides information about the risks and benefits of flu shots.

Fighting Back
An interactive game introduces you to immune system function. Use the Help Me button to get the instructions, then fight that virus! This is provided by PBS's NOVA series.

What the Heck Is an Allergy?
An introductory article from the Bugs in the News site.

American Academy of Allergy, Asthma, and Immunology
This medical organization site provides research news and a patient/public resource center with brochures about allergy, asthma, and related subjects.

Poison Ivy: An Exaggerated Immune Response to Nothing Much
The response to poison ivy is used to explain a variety of immune processes. From the University of Massachusetts at Amherst.

Primary Immunodeficiency
This brochure from the National Institute of Child Health and Development describes the normal immune system and the genetics, symptoms, and treatment of PI.

AIDS, HIV, and the Immune System
A good text introduction to AIDS and how it affects the immune system, from the Bugs in the News site.

Molecule of the Month: Caspases
Capsases are protein-slicing enzymes that spring into action during apoptosis.

Xenotransplantation
Pros and cons of using animal organs to save human lives.

Heart Transplantation
Latest news and information about heart transplanation from the National Institutes of Health.

Emerging Infectious Disease
Animation, images, and video from Rediscovering Biology, a project of the Annenberg Foundation and the Corporation for Public Broadcasting.

NOVA: BioTerror
PBS's NOVA online reviews the past -- and the unfolding -- history of biowarfare and bioterrorism.

Bad Bug Book
The Food and Drug Administration provides this guide to foodborne pathogens and natural toxins.

Centers for Disease Control and Prevention
Online source for credible health information

The Big Picture Book of Viruses
Pictures and information about viruses, from Tulane University.

Institute for Molecular Virology
Includes a "Virus of the Month" profile, news about viruses, and computer models and animation of viruses. It's from the University of Wisconsin.

An Electronic Introduction to Molecular Virology
A tutorial from the University of Cape Town in South Africa. It covers both the basics and the more esoteric details.

Mad Cow Comes to Town
From the Why Files site, a review of what is known about prion diseases and an assessment of the latest threat in the United States.

Microbes: What They Do and How Antibiotics Change Them
The author argues that antibiotics and antibacterials are making microbes tougher.

Intimate Strangers: Unseen Life on Earth
A PBS site about the systematics, ecological importance, and dangers of microbes.

Introduction to Bacterial Structure
Material from an online textbook from the University of Wisconsin-Madison.

Infectious Disease Animations
From Howard Hughes Medical Institute, animation of infection and multiplication by E.coli and Salmonella, and of bacterial conjugation.

Bacterial Divide and Multiply
Information and a movie about bacterial growth and its limits. It's from the marvelous Cells Alive site.

Laboratory of Molecular Parasitology
Information and a video of trypanosomes from this lab at Rockefeller University.

Parasitic Disease Information
This U.S. government site provides a wealth of information about diseases caused by protistans.

Malaria Foundation International
This nonprofit organization provides travel advisories, information about malaria projects, and lots of links.

HIV in Action
Animation created by a neurobiologist and AIDS researcher at the University of Iowa College of Medicine. It's on PBS's NOVA site.

Human Immunodeficiency Virus (HIV) Infection
A page from the Cells Alive site that explains in step-by-step fashion the mechanism of infection.

HIV Knowledge Base
A comprehensive, on-line textbook of HIV disease from the University of California San Francisco and San Francisco General Hospital.

World AIDS Day Photo Gallery
This photo essay from the World Bank Group puts a human face on the African AIDS epidemic.

Simulating the Spread of HIV
This "Web lab" from the University of Arizona Biology Project simulates the potential spread of HIV through a population.

FamilyDoctor.org: Sexually Transmitted Diseases
A collection of pamplets and other educational resources provided by the American Academy of Family Physicians.

STD Prevention
The CDC's Division of Sexually Transmitted Diseases.

Sexually Transmitted Diseases Problem Set
A tutorial quiz from The Biology Project at the University of Arizona.

Secrets of the Dead: The Syphilis Enigma
From PBS, a supplement to a television program about the origins and spread of syphilis.

Genital Warts
A pamphlet from the American Academy of Dermatology with some graphic images.

Pubic Lice
Photos and information from medical associations and government agencies. This site also has information on most other STDs.

Pandemic Influenza
CDC's website lists the phases of the Influenza (Flu) pandemic.

Site dedicated to the handling of scorpions
Interested in keeping a scorpion as a pet? Learn about what scorpions eat, how to recreate their natural habitat, and how to handle a scorpion. Click on "Bug Club" to learn about keeping various insects as pets.

Australian Museum: insect fact sheet and resources
The Australian Museum has information on insect metamorphosis, bites and stings, insects as pets, and an informative insect fact sheet. Click on "Conservation and Biodiversity" to learn about conservation efforts for endangered insect species in Australia.

Iowa state university: entomology webpage
Learn about beetles, butterflies, mosquitoes, grasshoppers, and other insects through pictures. Links to articles accompany some of the pictures.

Site featuring insect related news articles
Features insect related articles. Click on right-side menu to look at galleries of different insects. Click on "Secret Weapons" to learn about defense mechanisms of various insects.

Bugbios
A site dedicated to the promotion of insects. Information on insects classes with many accompanying pictures.

Lichens of North America
A website that offers beautiful photos of Lichens in North America and their importance in nature. Learn about how humans have used lichen and the various places in North America where they grow.

Lichen overview
An illustrated look at the biology of lichen. Click on "Lichenland Main Door" to learn how to identify lichen by their physical characteristics.

Lichens survive in space
The results of an experiment by the European Space Agency show that lichens are adepts at surviving in open space.

UC Berkeley: Intro to Lichens
UC Berkeley's biology website on lichens. Includes information about lichens in the fossil record, life history and ecology, systematics, and morphology.

Lichen Biomonitoring
Lichens are good biomonitors: they serve as good indicators of air quality.

Lichen Lore, lichens in history
Some interesting facts about lichens and their practical uses. Includes photos and some fun questions.

How will forest management practices affect lichens
How does forest management affect lichens in the Pacific Northwest? Click "Questions" to find out. "Last Best Lichen Places" has a list of the best places where you can see lichens.

American Bryological and Lichenological Society
A group dedicated to the study of bryophytes and lichen and is one of the oldest botanical organizations in the United States. Click "Publications" to see an up-to-date list of publications on lichens and bryophytes.

Basic Energy Concepts
A section from the microtextbook by Timothy Paustian at the University of Wisconsin-Madison.

Molecule of the Month: ATP
An illustrated article about the structure and function of ATP from Bristol University in the U.K.

What the Heck Is an Enzyme?
One of a series of "What the Heck?" articles from the University of Kansas. This one provides an introduction to enzyme function.

No LFS, No Cry
A team of Japanese scientists have described the enzyme pathway that causes people to tear in response to onions.

Molecule of the Month: Glycolytic Enzymes
The reactions of glycolysis don't proceed on their own. Each reaction is catalyzed by an enzyme. This review of the enzymes will help you understand glycolysis, and give you a better grasp of the types of reactions that occur in all cells.

Introduction to Enzymes
Worthington Biochemical Corporation, a commercial supplier of enzymes, explains the importance of these proteins in life processes.

The Chemistry of Health
An online book describes how biochemistry relates to human health. There's information about metabolism, enzyme action, and loads of additional subjects.

The Citric Acid Cycle
An animated online lesson designed to supplement a biochemistry text.

Glycolysis
This page from the Medical Biochemistry site covers a variety of glycolysis-related topics.

Mitochondrial Mysteries Demystified
An excellent multimedia presentation. This covers mitochondrial structure, the TCA cycle, coupled reactions, ATP synthesis, and the whole grand process. It was created at Taylor University.

Oxidative Phosphorylation
An animated online lesson designed to supplement a biochemistry text. It describes both substrate-level phosphorylation and oxidative phosphorylation.

Mechanism of Mitochondrial Electron Transport and Proton Pumping
A detailed animation accompanied by a text explanation, both by Steve Berg of Winona State University.

Glycolysis Tutorial
An excellent step-by-step animation from Northland College.

Cytochrome Oxidase
From the Protein Data Bank, Molecule of the Month. A description of the molecule that controls the last step of aerobic respiration.

Glycolysis
This page from the Medical Biochemistry site covers metabolism of carbohydrates.

Glycogen Phosphorylase
This Molecule of the Month is the enzyme that releases sugar from glycogen as the first step in making it ready for entry into glycolysis.

Pharmacology of Colchicine
Information about this spindle-stopping chemical.

Interactive Mitosis Tutorial
A Shockwave tutorial from San Diego State University that includes an interactive animation and a movie of mitosis in a plant cell.

Mitosis
Animation and text from the Molecular Biology Notebook.

Mitosis
A Flash tutorial that takes you step by step through the stages of the cell cycle.

Animal Cell Mitosis
An interaction from the Cells Alive site.

The Cytokinetic Mafia Home Page
Visit this site for movies of cytokinesis in a variety of organisms.

The Radiation Information Network
Idaho State University provides this marvelous link page. All material available via the links from this Web site has been reviewed and is believed to represent the current consensus of the facts on radiation and radiation protection.

Meiosis Tutorial
A tutorial quiz provided by The Biology Project at the University of Arizona.

Osmosis and Osmoregulation
From Gondar Designs Biology site, overview of osmosis and how it affects living organisms.

Osmosis
From Colorado State University's Portrait of a Cell site. Includes a rather complex simulation.

Membrane Transport Tutorial
An animated tutorial covers osmosis, diffusion, facilitated diffusion, and active transport.

Phagocytosis
From the Cells Alive site, a description and time-lapse video.

Overview of mollusks
An quick and straightforward overview of mollusks. Includes a look at the different classes of mollusks and some interesting facts about each.

Pictorial guide of mollusk shells
A comprehensive guide to mollusk shells and mollusk morphologies, courtesy of the Smithsonian Institution Libraries.

Zebra Mussels
USDA Invasive species website

The Cephalopod Page
Overview of cephalopods with recent articles. Click on the FAQ link to answer any questions you may have about cephalopods.

BBC fact sheet on snails
Fact sheet on the common garden snail. Includes information about the garden snail's diet, behavior, and reproduction.

Muscular System
Part of a training course developed at Emory University. It is beautifully illustrated. Use the links near the top of the page to go to the other sections of this module.

Lumen Dissector Muscle List
An interactive resource that will teach you the locations of each muscle in the human body. You can also choose to identify the muscles of various body regions.

Muscle Biochemistry
A very detailed description of the organization of the sarcomere and how the components interact to allow movement. From the Medical Biochemistry site.

Muscle Physiology
Most aspects of muscle physiology are covered on the University of San Diego site.

Muscle Physiology
A chapter from a physiology course at the University of Vermont.

Molecule of the Month: Myosin
llustrated information from the Protein Data Bank site.

Mechanism of Filament Sliding
A good animation of the events that cause muscle contraction. It was designed as a supplement to a neurobiology textbook.

Actin Myosin Crossbridge 3D Animation
From San Diego State University. A cool animation with a key to all the components.

Myosin Motor Units
Visit this site to learn more about ongoing research into movements that involve the protein myosin. The researchers at this University of Arizona lab study myosin mutants and have provided a wonderfully accessible description of their work.

From Sausages to Wrinkles
The story of the discovery and uses of botulinum toxin. This is an ExPSAy Protein spotlight article.

Anabolic Steroid Abuse
A report from the National Clearinghouse on Alcohol and Drug Information.

Androstenedione and Its Effects on Strength Training
The Nicholas Institute of Sports Medicine and Athletic Trauma evaluates the value and side effects of androstenedione.

Creatine, The Next Ergogenic Supplement?
A review article from the SportsScience site. It explains how creatine works in the body, its effects on performance and body composition, and the known side effects.

Society for Neuroscience
A useful source of information about the physiology of the nervous system and the latest research.

Neurobiology
Multimedia resources from the Rediscovering Biology site, a project of the Annenberg Foundation and the Corporation for Public Broadcasting.

Types of Neurons (Nerve Cells)
A highly accessible introduction to the structure of the neuron. It includes a quiz about the parts of the neuron and a link to a gallery of neurons. This is all part of a marvelous resource called Neuroscience for Kids.

Basic Neuronal Functioning
A tutorial covering, among other things, the structure of the neuron, and the physical factors involved in the action potential. Processes like diffusion demonstrated by simple animation.

Molecule of the Month: Potassium Channels
The flow of potassium across the neuron membrane is controlled by these vital channel proteins. This is one of the many protein profiles on the Protein Data Bank site.

Channel Gating during an Action Potential
A good animation of the events that occur during an action potential. It was designed as a supplement to a neurobiology textbook.

Understanding the Transmission of Nerve Impulses
An except from the Anatomy and Physiology for Dummies book.

Lights, Camera, Action Potential!
An excellent introduction from Neuroscience for Kids, courtesy of the University of Washington.

Molecule of the Month: Acetylcholinesterase
A profile of an enzyme that removes neurotransmitter from the synapse between a nerve cell and a muscle cell, and a discussion of what happens if the enzyme is destroyed or defective.

Calcium and Nerve Impulses
Researchers at Woods Hole Marine Biological Laboratory are studying the role of calcium in nerve cell function.

Making Connections - The Synapse
A highly accessible introduction to the function of the chemical synapse. It's well illustrated and includes rudimentary animations. See also The Synapse - Up Close and Personal and Neurotransmitters and Neuroactive Peptides.

How Do Nerve Cells Communicate Messages?
The answer, as you know, is by means of chemical synapses. Visit this page for a short straightforward article about synaptic transmission and neurotransmitters.

Groups of Nerves
This interactive page from the American Medical Association teaches the function of the various spinal nerves.

Divisions of the Nervous System
This page describes the functional divisions of the nervous system. It is from Neuroscience for Kids.

Nervous System
This is part of a training module developed at Emory University. Use the links near the top of the page to get deeper into the subject. Hypertext terms are linked to definitions.

The Nervous System
Information on the nervous system from Maricopa Community College webpage

Virtual Anatomy Textbook: The Nervous System
An excellent multimedia tool from the University of Illinois. It covers the central nervous system, the peripheral nervous system, and microanatomy of the nervous system.

Effects of Mercury on the Nervous System
From Neuroscience For Kids, a page about the hazards mercury poses to the nervous system.

The Autonomic Nervous System
An excellent introduction to the function of sympathetic and parasympathetic nerves from Neuroscience for Kids.

Spinal Cord Repair
This "Brain Briefing" from the Society for Neuroscience describes the latest research on spinal cord injury and repair.

Brainy Women
A Harvard Magazine article about the research of some female neuroscientists.

The Whole Brain Atlas
Lots of images of normal and abnormal brains. The section entitled "Top 100 Brain Structures" allows you to bring up a labeled diagram that shows the structure of interest.

The Charles A. Dana Foundation
This philanthropic foundation supports research on the brain and brain disorders.

The Ventricular System and CSF
Colorful illustrations, photos, and basic information from Neuroscience for Kids.

Secret Life of the Brain
A PBS site in support of this series about recent discoveries in brain research.

Lobes of the Brain
A colorful introduction to the location and function of the lobes of the human brain. It includes a quiz and some interesting links.

The Brain: Right down the Middle
This page uses an illustration of a sagittal section as the jumping-off point for an introduction to brain anatomy. It's from Neuroscience for Kids.

Sleep and learning
Society for Neuroscience article

American Academy of Neurology
Visit this medical association site for the extensive collection of patient information and brochures.

Multiple Sclerosis
Comprehensive information on multiple sclerosis, a disease that destroys the body's myelin sheaths from the National Institute of Neurological Disorders and Stroke.

National Institute of Mental Health
This government Web site provides up-to-the minute information about Alzheimer's disease and other mental disorders. There is a wealth of information here, so take some time to explore the site.

Alzheimer Brain Tour
This portion of Harvard's Whole Brain Atlas is an online tour of the brain of a woman with Alzheimer's disease.

Mirror Neurons
A PBS report on mirror neurons: "A recently discovered system in the brain may help explain why we humans can get so worked up watching other people."

Gallery of Neurons
A slide gallery of neurons. Take a look at what spinal cord neurons, cerebral cortex neurons, and cerebellum neurons look like.

The discovery of the neuron.
The story of the discovery of the neuron. Learn about the contributors to the field of neuroscience.

Alzheimer's Association
Learn about this Alzheimers, a debilitating disease that affects an estimated 4.5 million Americans. Learn about what's being done about this disease and what potential treatments for Alzheimers are on the horizon.

Kimball's Biology Pages
An overview of the synapse. Covers excitatory synapses, inhibitory synapses, and neurotransmitters.

University of Texas at Austin
A look at some common neurotransmitters and their functions. Click "drug interference" to see how drugs interfere with neurotransmitters function and click "Understanding addiction" to learn about how addiction occurs.

Mayo Clinic
The Mayo Clinic's webpage devoted to depression, which scientists believe may be caused by imbalances in neurotransmitters. Learn about depression and its contributing factors.

Intro to transpiration and its atmospheric effects
Water cycle and transpiration. Learn about transpiration and the atmospheric factors affecting this process. Click "evaporation" to visit the accompanying webpage that explains the ecological importance of evaporation and its part in the water cycle.

Phytoremediation: a case study
A case study of phytoremdiation in Fort Worth, Texas. Read about how effective phytoremediation was in this case and the results of the case study.

Phytoremediation overview
A site that looks at phytoremediation, the use of plants to collect toxins in the ground. Learn how plant transpiration can be used in efforts to clean the environment.

Plant Nutrients
An overview of important plant nutrients and soil texture and pH.

The Fertilizer Institute
TFI promotes the use of fertilizer and represents the fertilizer industry. Click on "facts&stats" to see videos about fertilizers role in maintaining healthy soils.

Types of Roots
About root types and functions

Life over Time
A virtual tour through the Chicago Field Museum. It stretches from the earliest cells to early humans.

History of Life
Introductory chapter to the Biodiversity and Conservation Hypertextbook by Peter Bryant.

The Origin of the Universe, Earth, and Life
A chapter from the National Academy of Sciences online version of "Evolution and Creationism."

The Cosmic Clock
Refined cosmic clock to determine the age of the Milky way.

From Primordial Soup to the Prebiotic Beach
An Access Excellence interview with Stanley Miller, the scientist whose study of the synthesis of organic compounds under the conditions that existed on early Earth is described in your text.

Were Bacteria the First Forms of Life on Earth?
An article from the Actionbioscience.org site tackles the question of how life began.

Environmental Literacy Council: pH Scale and Acid Rain
This site gives a brief description of the pH scale and defines acid rain. It includes links about the history of the pH scale and the pH of common substances.

Environment Protection Agency: pH scale summary and links
The EPA's website on pH gives a short description of the pH scale and discusses the effects of acid rain and how to reduce them. You can also find out about the local acid rain projects in your area.

Importance of soil pH
This webpage is part of Nasa's website on soil. Learn about the importance of soil pH in agriculture and the soil pH required to grow various crops.

Water Properties: pH
A pH scale that places some household liquids and water of various acidity in relation to each other. Click on the links at the bottom to learn about some common water measurements.

pH Scale: Information and Quiz
A quick overview of the pH scale. Take the quiz to test your understanding of the pH scale.

Arizona State University: Why study photosynthesis
This website lays out the role photosynthesis plays in our lives and its importance to the environment, our health and energy production. Also, Dr. Gust discusses the relevance of photosynthesis to electronics and medicine.

Photosynthesis as an energy source for humans
An article about the possibility of imitating nature to produce renewable energy without harming the environment.

Union of Concerned Scientists: Solar energy as an alternative energy resource
A comprehensive explanation of solar energy and its many applications. Learn about solar heat collection, solar paneling on buildings, and the future of solar power.

NASA: summary of the electromagnetic spectrum
A look at the electromagnetic spectrum, the different kinds of waves and the way we sense them, and the electromagnetic spectrum from space.

Chlorophyll and health
An informative site on what foods are chlorophyll rich and what beneficial properties chlorophyll have for our diets. Also, learn about the effects of cooking chlorophyll.

BBC news: The oldest evidence of photosynthesis on Earth
An article about an important finding that scientists claim to be the oldest evidence of photosynthesis.

Jane Goodall Institute
The Jane Goodall Institute has information about primates and their habitats. Click on "chimpanzee central" to learn all about our close relatives.

Smithsonian: Great Apes and other Primates
The Smithsonian National Zoo's website has information about great apes and other primates. Includes information about primate cognizance and habitat conservation.

University of Arizona: Primate features
What makes a primate a primate? Learn about primate skeletal features, evolution, and behavior.

Smithsonian: Human Ancestry
The Smithsonian Human Origins Program. Click on "The Hall of Human Ancestors" to learn about five million years of human evolution.

The Cave of Lascaux: Paleolithic art
The Cave of Lascaux, one of the most famous sites of prehistoric art. Click on "Virtual visit" to see beautiful pictures of the art.

National Geographic: Japanese Macaque culture
Japanese Macaques have been observed exhibiting cultural behavior of their own. Learn about the behavioral traditions that get passed down from generation to generation.

World's oldest organism
Scientists claim 250 million old bacteria trapped in suspended animation are the world's oldest living things.

Disarming Harmful bacteria
Learn about a new approach for disarming bacteria that may prove more effective than antibiotics.

Probiotics
A definition of probiotics and its health benefits.

UC Berkley website: general description of bacteria
UC Berkeley's biology website on bacteria. Includes information about bacteria in the fossil record, life history and ecology, systematics, and morphology.

UC Berkley website: general description of archaea
UC Berkeley's biology website on archaea. Includes information about archaea in the fossil record, life history and ecology, systematics, and morphology.

FDA: Antibiotic resistance
FDA's website on antibiotics and drug resistance in bacteria. Click on "Animated videos" to watch how antimicrobial resistance develops and spreads among bacteria.

NOVA: interview with an extremophile biologist
NOVA interview with Diana Northup, a microbiologist who's fascinated by extremophiles, organisms that live in environments that would kill most organisms.

The Respiratory System
An interactive page from the American Medical Association's patient education section.

Respiratory System
This is part of a training module developed at Emory University and is beautifully illustrated.

Introductory Anatomy - Respiratory System
Lecture notes for a course from the Centre for Human Biology, University of Leeds (UK).

Molecule of the Month: Carbonic Anhydrase
A profile of the enzyme that catalyzes the conversion of carbon dioxide to carbonic acid and bicarbonate ions.

American Lung Association
Information about lung disease, including tobacco-induced disease. You can subscribe to their e-mail publication on lung health and learn about programs and events in your area.

Breath of Life
A National Library of Medicine exhibit about asthma.

Respiratory Problems
Health Information Topics for Respiratory Problems

CT Lung Fly Through
A high-tech look at the lung. It is an MPEG animation created from CT scans. The lungs are in blue and the green spot is a tumor.

How we breath
WebMD site on how the lungs work

The Lungs
An exhibit from the Science Museum of Minnesota shows lung anatomy and the normal respiratory cycle.

Molecule of the Month: Hemoglobin
A profile of the most important respiratory pigment is provided by the Protein Data Bank site.

Blood Gases
A menu with information about the physiology of gas exchange and the role of the respiratory system in acid-base physiology. This is part of the Blood Gases Computer Program Manual, by B. Argyle, M.D.

CDC Tobacco Information and Prevention Source
This government source provides information about the health effects of tobacco use and how to quit smoking.

Smoking and Cancer
Visit this Oncolink page to keep abreast of the latest discoveries related to smoking and its health effects.

Environmental Tobacco Smoke and Lung Development Activity
A data collection and analysis activity from the University of Arizona's Biology Project site.

Becoming a Scientist
What does it take to be a scientist? On this portion of the Howard Hughes Medical Institute, scientists discuss their experiences. You can read transcripts or watch video.

Findings
An online magazine that profiles scientists doing cutting-edge biology and chemistry research

People Doing Science
NIH provides this archive filled with profiles of scientists and others in science-related careers.

Timelinescience
A guide to the scientific discoveries of the past thousand years.

Animal Diversity Web
A terrific resource from the University of Michigan. It covers only the Animalia kingdom.

The Tree of Life
Introductory page to an ever-expanding collection of resources devoted to the diversity of life on Earth.

Web Lift to Any Taxon
This useful page from the University of California Museum of Paleontology will help you find information about the many groups of organisms, living and extinct.

Ecological Society of America
A site filled with information about the study of ecosystems and human impacts on them.

Basic vs. Applied Research
What's the difference between basic and applied research? Which do we need most? Visit this Lawrence Berkeley National Laboratory site for a discussion of these questions.

Discovery, Chance, and the Scientific Method
Think that scientists always know what they're doing? Get over it! This article from Access Excellence explores the role of serendipity in the discovery of penicillin.

Introduction to the Scientific Method
Physicist Frank Wolf addresses research steps, common mistakes, and circumstances in which scientific method is not applicable.

The Importance of Understanding Science
An interview with physicist David Balamuth in the University of Pennsylvania's Arts and Sciences magazine.

The Scientific Method Quiz
Test your science savvy with this quiz from General Chemistry online.

Bioethics.net
The American Journal of Bioethics provides this site. It addresses many of the controversial questions raised by advances in biology. It's also a great source of breaking science news.

Roundtable: Science and Faith
As part of the PBS series "Evolution," a panel of scientists answered questions about how they view science and faith.

Science and the Psychology of Beliefs
An interview with Michael Shermer, founder of Skeptic magazine.

Scientific Notebook: Science and Creationism
A nice explanation of the process of science and a discussion of how this relates to creationism.

Health Insight - Consumer's Guide
A project designed to help consumers evaluate health and scientific information.

Herbal supplements: What to know before you buy
Information from the Mayo Clinic's Complementary and Alternative Medicine Center. This page includes a menu with links to related articles on this site.

Tips For The Savvy Supplement User
The FDA provides this hyperlinked article about the use of dietary supplements. It includes a section about evaluating information about supplements on the Web. Also see Separating Herbal Supplement Fact From Fiction from the Council for Responsible Nutrition.

Michigan State University
A summary of different type of bryophytes: mosses, liverworts, and hornworts. Includes a simplified overview of alternate generations.

Mosses and Liverworts (Bryophyta)
An introduction to bryophytes, alternative generations, and their evolutionary position.

UC Berkeley: Intro to Byophytes
UC Berkeley's biology website on mosses. Includes information about mosses in the fossil record, life history and ecology, systematics, and morphology.

Missouri Botanical Garden: byrophytes
This website has a checklist of mosses, a list of the 12,800 recognized species. Includes information about moss flora in Central America, Thailand, Chile, and the Andes.

British Bryological Society
Dedicated to the conservation of mosses and other bryophytes. Go to "Resources" in the menu to see a photo gallery of bryophytes and recent publications on bryophytes.

The Hidden Forest: Bryophytes
A good overview of bryophytes, their alternative generation, plant parts, and a list of differences between mosses and liverworts.

Seeing, Hearing, and Smelling the World
A wonderful, photo-rich report from the Howard Hughes Medical Institute about the latest research into the senses.

Monell Chemical Senses Center
This research center provides topical newsletters for the general public. They are available as pdf files.

Converging Pathways of Pain Research
NIH's Museum of Medical Research provides a historical look at our understanding of pain and ways to relieve it.

Pain and Why It Hurts
An excellent introduction to how pain is perceived and the evolutionary basis for this sensation. This is from the Neuroscience for Kids.

Synaesthesia/Sense of Touch
A National Public Radio "Science Friday" program about the latest research into the sense of touch and about synaesthesia, a condition in which a person interprets a signal from one of the senses with another sense entirely. You will need to have a RealAudio player to listen to this program. You may also wish to listen to the program about The Sense of Smell.

Physiology of Taste
A jargon-free explanation by Michael Berry.

Olfaction - A Review
An excellent illustrated review of the physiology of olfaction. It is provided by Leffingwell and Associates, a company that services the food, beverage, and perfume industries.

Olfaction
A tutorial on the sense of smell by Tim Jacob of Cardiff Univesity. See also his Physiology of Taste.

Fire and Spice
This feature article from the General Chemistry Online site describes how the shape of organic molecules is related to our perception of flavor.

EarWorks
Micrographs and animation from the department of neurophysiology at the University of Wisconsin -- Madison.

Virtual Tour of the Ear
Highly detailed information from a variety of sources has been compiled into this text and graphics "tour." From Augustana College in South Dakota.

National Institute on Deafness and Other Communication Disorders
This government site has information about the physiology of hearing and balance, as well as smell and taste.

Cochlear Fluids Research Laboratory
This Washington University School of Medicine site describes the anatomy of the inner ear and ongoing research studies.

Sound and Fury
A PBS NOVA site about the use of cochlear implants to cure deafness. Find out how the implants work and why many deaf people worry about their use.

The Vestibular Disorders Association
In addition to information about disorders, there is a section with definitions of vestibular terms and a graphic that illustrates the anatomy of the inner ear.

Noise Pollution Clearinghouse
A national non-profit organization with extensive noise related resources.

Special Senses: Eye and Ear
Notes and micrographs from a Veterinary Histology course.

Cow's Eye Dissection
A primer about the vertebrate eye and a step-by-step view of a dissection from San Francisco's Exploratorium.

Webvision
Detailed information and diagrams about eye anatomy and the neurology of vision.

Receptive Field Tutorial
An explanation of receptive fields in the visual system, from the Psychology Department at Hanover College.

National Eye Institute
This government agency provides a wealth of information about eye diseases and vision research. There's also a Glossary of Eye-Related Terms.

American Academy of Ophthalmology
A professional organization site that provides news and online education resources.

The Foundation Fighting Blindness
Non-profit organization that funds research on blindess. Provides information about various causes of blindness.

Helping Young People Delay Sexual Intercourse
Extensive information on sex and sexually transmitted diseases and how to prevent them.

Sexually Transmitted Diseases
Center for Disease Control site provides general information on several sexually transmitted diseases.

Journal of the American Sexually Transmitted Disease Association
Publishes peer-reviewed articles on on clinical, laboratory, immunologic, epidemiologic, sociologic, and historical topics pertaining to sexually transmitted diseases and related fields.

HIV InSite
Comprehensive, up-to-date information on HIV, provided by University of California, San Francisco.

Structure of Bone Tissue
Part of a training course developed at Emory University. Use the links near the top of the page to go to the other sections of this module.

Bone Biology for Kids
A graphics-rich site from the University of Washington that covers bone cells, how a bone biopsy is done, bone diseases, and more.

The eSkeletons Project
A comparative anatomy site that allows you to view a variety of primate skeletons, including a human. You'll need to download the appropriate plug-ins to see the images.

Inner Body Skeleton Tutorial
A 61-page animation-rich tutorial about the human skeleton. You'll need to have a Java-enabled browser to use it.

The Skeletal System
An overview and links to pages that cover the components of the axial and appendicular skeleton. This is part of the human anatomy exhibit on the e-museum site of Minnesota State University.

Skull Module
An cool use of interactivity. Click the bone on the skull graphic to bring up a QuickTime VR movie of that human bone. You can use your mouse to rotate the bone. This is from California State University in Chico.

Access Excellence: Living Skeleton
X-rays of the human skeleton, both normal and injured, from Access Excellence.

Knee, Shoulder, Hip
Shockwave tutorials from an orthopedic surgeon's site show anatomy and common surgical procedures.

Hypermuscle: Muscles in Action
Want to learn the names of the different types of movements made by your body? You can download movies of muscle actions at this site from the University of Michigan Medical Center Learning Resource Center.

American Academy of Orthopedic Surgeons
Visit this site for information about the musculoskeletal system from the physicians that treat it.

Medem: Bone, Joint, and Rheumatic Conditions
Information from U.S. medical societies.

NIH Osteoporosis and Related Bone Diseases National Resource Center
A searchable government site with bone health information, research bibliographies, and links to other governmental and organizational sites.

National Osteoporosis Foundation
This nonprofit organization fund researches and promotes education about bone health and osteoporosis.

Osteoporosis and Bone Physiology
This site is designed to educate physicians and patients about osteoporosis and bone physiology. It was created and is maintained by Susan Ott, MD, at the University of Washington.

Anatomy of the Skin
A collection of micrographs of the skin, provided by the Internet Dermatology Society.

Dermatology Cinema (Skinema)
A page by dermatologist and film buff Dr. Reese, which will keep you updated on the skin condition of the stars and explain all those weird symptoms you've seen in the movies.

Introduction to the Skin
Diagrams and micrographs from the Loyola University Medical Education Network.

American Academy of Dermatology
There's a wealth of skin-related patient information on this medical organization's site.

Introduction to Skin Cancer
A Hawaiian site that will convince you to limit your time in the sun, or at least use a sun block. You can also access relevant news and check on the daily UV forecast for cities throughout the United States.

Health Effects from Increased Exposure to Ultraviolet-B due to Stratospheric Ozone Depletion
A thematic guide developed by the Center for International Earth Science Information.

Information on UV Radiation
Information about the different forms of UV radiation, the types of skin cancer, and other health effects of UV.

Technological inspiration from sponges
Daniel Morse is developing complex semiconductor devies from sponges. Learn how sponges are being used for constructing complex structures and how this technology could lead to better solar cells.

PBS: Sponges—the first animal
What was the first animal? PBS investigates this question, offering videos and pictures of sponges and stories of scientists who discovered proof of the first animal.

Research shows natural compound in marine sponges reduces cancer cell motility
Medical news on sponges used in medical research

Replacement Parts: Creating Artificial Tissues and Organs that Work
A 1996 article from "Frontiers," the electronic newsletter of the National Science Foundation.

The Bionic Body
A Web feature to support the "Scientific American Frontiers" show on PBS.

The Why Files Guide to Stem Cells
This Why Files site describes both the scientific and the social issues raised by stem cell research.

Membranes
This is part of a training module developed at Emory University.

BBC: The Human Body
Interactive games and tutorials introduce organ systems on this marvelous BCC site.

The Virtual Body
Beautifully illustrated tutorials and animation about the brain, skeleton, heart, and digestive system.

Human Anatomy Online
An interactive introduction to the tissues and organs of the human body. It's designed for a general audience and is both basic and relatively jargon-free.

Atlas of the Human Body
The American Medical Association provides this introduction to human anatomy that includes sections on the torso, muscles, heart, and skeleton.

Visible Human Browsers
A wonderful look inside the human body. It's a three-dimensional, high-resolution database of human male and female anatomy derived from direct analysis of anatomical specimens and radiological imaging.

Kimball's Biology Pages
A look at the various ways with which we create the tree of life including anatomical homology, protein sequences, and DNA-DNA hybridization.

Tree of Life Web Project
Explore the tree of life. Navigate through the website using the main Tree of Life figure on the homepage.

The Barcode of Life
Learn about the "Barcode of Life", a short DNA sequence from a uniform locality on the genome that's used to identify species. Browse the various articles written on the DNA Barcode under "Press Commentary".

UC Berkley website: introduction to phylogeny
UC Berkeley's webpage on phylogeny, the tree of life, time periods on earth, and a helpful glossary.

BBC news: Early life thrived in lava flows
Evidence of where microbes burrowed into volcanic glass 3.5 billion years ago shows early life thrived in lava flows

Did life first spring from clay?
This article discuses the a particular clay mineral that helps the assembly of RNA.

An Interview with Stanley Miller
In this interview, Stanley Miller talks about exobiology, the field his work helped make famous.

Endosymbiosis Theory
A look at evolutionist Lynn Margulis' research on endosymbiosis and its relevance to the evolution of eukaryotic cells.

Types of leaves
A quick tutorial on leaf parts. Navigate through the website by clicking on the controls on the bottom left.

Inside a leaf
Anatomy and function of a leaf

Washington State University: edible leaves
Looks at parts of leaves that we commonly eat such as celery, spinach, and artichokes.

Identify a tree by its leaves
Identify a tree by its leaves. Use the guide to learn about different types of leaves and trees and where in North America they can be found.

Hikers guide leaf identification
A hikers guide to identifying leaves by their morphology. Has a very simple interface with pictures that educates you on various leaf parts as you navigate.

HistoWeb
Slides and notes from the University of Kansas Medical Center.

Histology
Drawings, micrographs, and notes provided by Dr. Roger Wagner at the University of Delaware.

Epithelium and Simple Glands
This series of slides with descriptions is part of a histology course on the Loyola University Medical Education Network.

Epithelial Tissue
A page from a training manual developed at Emory University.

Connective Tissue Proper
Connective Tissue Slides from the Loyola University Medical Education Network. Use the "Next" button to view the lessons about connective tissue cells and specialized connective tissues.

Connective Tissue
A page from a training manual developed at Emory University. Hypertext terms are linked to definitions.

Questions and Answers about Heritable Disorders of Connective Tissue
Information from the National Institute of Arthritis and Musculoskeletal and Skin Disease.

Muscle Tissue
A page from a training manual developed at Emory University. Hypertext terms are linked to definitions.

Muscle Tissue
This series of slides with descriptions is part of a histology course on the Loyola University Medical Education Network.

Muscle Physiology
Most aspects of muscle physiology are covered on the University of California, San Diego, site.

Muscle Biochemistry
A very detailed description of the organization of the sarcomere and how the components interact to allow movement. From Medical Biochemistry site.

Nervous Tissue
A page from a training manual developed at Emory University. Hypertext terms are linked to definitions.

Neural Tissue
Slides with descriptions from a histology course on the Loyola University Medical Education Network.

Eric H. Chudler's Home Page
Chudler has created and compiled a terrific collection of material about nervous tissue and the nervous system. Neuroscience for Kids is a good place to start.

Stem Cells and the Future of Regenerative Medicine
A searchable full-text book published by the National Academy Press.

Patches for a Human Heart
NASA scientists have bioengineered a small patch of heart tissue. The page includes video of the beating tissue.

DNA Replication
An online lesson designed to supplement a biochemistry textbook.

Steps of DNA Replication
The mystery of the steps of DNA Replication of the Eykaryotes

DNA Workshop
This page from the site for the PBS series A Science Odyssey provides an interactive Shockwave activity that explains DNA replication. You'll also want to check out the links to related material on the same site.

Nuts and Bolts of DNA Replication
An animation from PBS's Evolution site. It includes an example of how a change in one base pair signals a "mistake," or mutation.

Molecule of the Month: DNA Ligase
A profile of a DNA repair enzyme that reconnects strands when they are broken.

DNA Replication
A step-by-step animation of DNA replication by John Giannini of St. Olaf's College.

Molecule of the Month: DNA Polymerase
An illustrated description of the structure and function of DNA polymerase, from the Protein Data Bank Web site.

Molecule of the Month: RNA Polymerase
This Protein Data Bank profile introduces this vital RNA synthesizing enzyme.

Deciphering the Genetic Code
An online exhibit from the National Institute of Health. It describes Nirenberg's experiments and puts his "cracking" the genetic code in a historical perspective.

DNA Words Are Three Letters Long
This portion of the DNA From the Beginning site describes the experiments that "cracked" the genetic code. It includes photos, animation, audio, and video.

Nobel Prize in Physiology or Medicine 1968
The 1968 prize was awarded for "interpretation of the genetic code and its function in protein synthesis." The site includes biographies of Marshall W. Nirenberg, Har Gobind Khorana, and Robert W. Holley. The presentation speech details the research for which the prize was awarded.

Molecule of the Month: Transfer RNA
This illustrated "Molecule of the Month" feature on the Protein Data Bank site describes the structure and function of transfer RNA.

Role of the Ribosome
A page from a cell biology site by Dr. Gwen Childs at the University of Arkansas.

Molecule of the Month: Ribosome
This illustrated "molecule of the month" feature on the Protein Data Bank site describes the structure and function of ribosomes.

Translation
QuickTime and Shockwave animations of eukaryotic translation are provided by the University of Wisconsin's BioWeb site.

Protein Synthesis
An extremely detailed description of translation from the Medical Biochemistry site.

What Makes a Firefly Glow?
The Genetic Science Learning Center provides this example of protein synthesis.

DNA-RNA-Protein
The Nobel Foundation has put together a terrific resource filled with text, illustration, and animation. Material is available at either a basic or an advanced level.

Drinking Water and Health
Information from the U.S. Environmental Protection Agency.

Fluid and Electrolyte Balance
Information about fluid and electrolyte balance from Medline Plus.

Osmoregulation
A basic overview of processes of osmoregulation. The target audience is high school students.

Introductory Anatomy - Excretory & Reproductive Systems
Lecture notes for a course from the Centre for Human Biology, University of Leeds (UK).

Virtual Fetal Pig Dissection - Excretory System
A look at the excretory system of a fetal pig. It is provided by Whitman College. There is also an Excretory System Quiz, available from the Main Page of the site.

Urinary System
This is part of a training module developed at Emory University and is beautifully illustrated.

Your Kidneys and How They Work
One of the many patient education brochures available from the Digital Urology Journal site.

Kidney Physiology
Control of blood pressure and the juxtaglomerular apparatus are among the topics covered on this Cardiff School of Biosciences site.

What I need to know about Urinary Tract Infections
Basic information for patients from the National Kidney and Urological Diseases Clearinghouse.

Antidiuretic Hormone (Vasopressin)
Part of the Pathophysiology of the Endocrine System Hypertextbook from Colorado State University. This is a well-done, highly accessible resource. For information about aldosterone, see Mineralocorticoids.

Clinical Correlates of pH Levels
Part of The Biology Project, an interactive online resource for learning biology, developed at the University of Arizona.

NIDDK
This government site provides information about prostatitis, cystitis, and other disorders. It includes statistics about the frequency of these ailments in the United States.

American Journal of Kidney Diseases
This site provides free access to journal abstracts and to an image-rich Atlas of Renal Pathology.

Center for Disease and Prevention: HIV/AIDS
The Center for Disease and Prevention's webpage on HIV/AIDS. Includes a fact sheet, important information on its transmission and prevention.

Pandemic flu fact sheet by the government
Information on avian and pandemic flu. Click on map to learn about pandemic planning in your state.

Summary of water's chemical properties from the U.S. Geological Survey
This site takes a look at the physical and chemical properties of water and includes a true/false quiz with some surprising answers. The site includes information about Earth's water and the water cycle.

Water: Properties and Behavior
This site by Visionlearning focuses on hydrogen bonding in water and water as a solvent.

Environmental Protection Agency: water information and most current issues
The EPA provides information about ground and drinking water, water science, wastewater management, wetlands, oceans, and watersheds.

Rocky Mountain Institute 's water resources
The Rocky Mountain Institute works in Household water efficiency, water efficiency policy and implementation, infrastructure and system planning, and commercial water efficiency. It offers practical ways for us to be more efficient with our water usage.

Mayo Clinic: water and health
The Mayo Clinic's website offers a simple guide to water's importance in human health. Learn about how much water you need, factors that influence water needs, and dehydration.

PBS: Troubled Waters
PBS examines a series of unusual and troubling animal behavior and sicknesses occurring around the world, and their underlying factor: water.