Home / Teaching Documents, Lecture Notes and Tutorials / Teaching Documents about Biology

! Stephen T. Abedon, Ohio State University, Mansfield: Biology Lecture Notes. PDF and Powerpoint files. Excellent!
Recovered from the Internet Archive´s Wayback Machine.

Gregory Ahearn, University of North Florida: The Diversity of Prokaryotes and Viruses. In PDF.
This expired link is now available through the Internet Archive´s Wayback Machine.

Alexa (Alexa Internet, Inc., an Amazon.com Company). Alexa is a Web Information Company, perhaps best known for the Alexa Rank, the website ranking system which tracks over 30 million websites worldwide. See especially: The top ranked sites in category "Science". Go to:
! Biology.

David L. Alles, Western Washington University, Bellingham, WA: Biology 101: An Introduction to Science and Biology. (PDF files).

John Alroy, Smithsonian Institution´s Department of Paleobiology: Lefalophodon: A History of Evolutionary Biology Web Site.
This page is an informal guide to the history of evolutionary biology from about 1800 to about 1950.
This expired link is still available through the Internet Archive´s Wayback Machine.

! L.M. Alves, Manhattan College, and P.A. Grove, College of Mount Saint Vincent: Teaching Introductory Biology. Go to: Rich Sources of Links for Introductory Biology.

The American Society for Cell Biology (supported by the Howard Hughes Medical Institute): Cell Biology Education. A Journal of Life Science Education. Go to: Points of View: Lectures: Can't Learn With Them, Can't Learn Without Them. A Combination of Lectures, Problem Sets, and Recitation Sections Is an Excellent Way To Teach Undergraduate Cell Biology at a High Level (by Harvey F. Lodish and Roberto K. Rodriguez), and Talking Biology: Learning Outside the Book and the Lecture (by Daniel J. Klionsky).

John R. Anderson, Georgia Perimeter College Geology: The World of Geology, Prefix/Suffix Meanings. Website saved by the Internet Archive´s Wayback Machine.
See also here.

Annenberg Learner (media and telecommunications to advance excellent teaching in American schools):
Rediscovering Biology. An online textbook, written by multiple authors (UMass Amherst, University of Missouri-St. Louis, Portland Community College).
The link is to a version archived by the Internet Archive´s Wayback Machine.

Anonymus (?, see also here): Leavingbio.net. This website will guide you through the main topics of Biology.

Arlington Central School District, LaGrangeville, NY:
Welcome to Biology. Lecture note, Powerpoint presentation.

! Lorna Ash & Brett Poulin, Department of Biological Sciences, University of Alberta: Instructional Multimedia, Multimedia Topics, Introductory Biology. Go to: The Carbon Cycle, The Nitrogen Cycle. Online and downloadable flash movies. Excellent!
Now provided by the Internet Archive´s Wayback Machine.

! S. Asche et al. (2023): What it takes to solve the Origin (s) of Life: An integrated review of techniques. Free access, arXiv.
! Note figure 1: Comprehensive array of experimental and computational techniques, along with conceptual bridges, which are primarily utilised in OoL studies.
"... We review the common tools and techniques that have been used significantly in OoL [origin(s) of life] studies in recent years.
[...] it spans broadly — from analytical chemistry to mathematical models — and highlights areas of future work ..."

Gordon Beakes (2002): A picture is worth a thousand words. A personal view of using images in the teaching of the biological sciences. PDF file. Provided by the Internet Archive´s Wayback Machine.

! Biology Junction.
Biology Junction has a dedicated team of specialists whose mission in life is to turn AP Biology from what some would call a lackluster science lecture series into a more proactive learning experience. Introduction to Biology. Go to:
! Introduction to Biology Lecture notes, Powerpoint presentation.

! The University of California Museum of Paleontology, Berkeley:
Understanding Science. Understanding Science provides a free resource that accurately communicates what science is and how it really works. An excellent resource, especially for teachers!
Don't miss to go to the Resource library.

Department of Integrative Biology, University of California, Berkeley: Plant Biology - Evolution - Ecology.

! Debashish Bhattachatya et al. (2009): Eukaryotes (Eukaryota). PDF file, In: S.B. Hedges and S. Kumar (eds.): The Timetree of Life (see here).

! BioDeepTime:
This project seeks to address one of the central challenges in biodiversity science by compiling and harmonizing ecological time series from modern and fossil sources to investigate how biological dynamics and drivers vary across timescales ranging from months to millions of years. Note likewise here.
Please take notice:
! J. Smith et al. (2023): BioDeepTime: A database of biodiversity time series for modern and fossil assemblages. Open access, Global Ecol Biogeogr.
Note table 1: Approximate temporal grain (the amount of time represented in a sample) for time series, number of time series and number of samples from source databases included in BioDeepTime.
"... The BioDeepTime database enables integrated biodiversity analyses across a far greater range of temporal scales than has previously been possible. It can be used to provide critical insights into how natural systems will respond to ongoing and future environmental changes as well as new opportunities for theoretical insights into the temporal scaling of biodiversity dynamics ..."

BioExplorer.Net. An annotated link directory. Go to: History of Biology .

! Biologie-Schule.de:
Lecture notes, in German.

Biology-Nation. This website provides resources for anyone with an interest in biology. (see also Biology-Nation.com Whois Record). Many links lead to Wikipedia. Go to: Introduction to Botany, The History of Biology and List of Biology Disciplines by Course.

Biology Online. Information in the Life Sciences. Go to: Tutorials > Cell Biology.

blaquedragonfly.weebly.com (?):
BIOLOGY STUDY RESOURCES. Biology lecture notes, Powerpoint presentations, e.g.:
The History of Life on Earth.

BookRags, a research location for students of any age: Biology.

Neil Buckley, Department of Biological Sciences, SUNY Plattsburgh, Plattsburgh, NY: Bio 102 General Biology II Class Notes. Powerpoint presentations. Go to:
An overview of Plant Evolution. Key Moments in the life of Kingdom Plantae.
Websites still available via Internet Archive Wayback Machine.

! Science Education Resource Center, Carleton College, Northfield, MN: On the Cutting Edge, Workshops for Geoscience Faculty. Go to: Resources for Teaching Biocomplexity in the Geosciences. This site contains a variety of resources related to biocomplexity, including biological, geological, chemical, physical and human systems. You will find links to activites and assignments, internet and computer resources, publications, presentations, a group listserv, and lots of creative ideas for teaching biocomplexity.

Cold Spring Harbor Laboratory:
DNA from the Beginning.
This excellent animated and easy to understand online textbook is organized around key concepts. The science behind each concept is explained by: animation, image gallery, video interviews, problem, biographies, and links.
Still available via Internet Archive Wayback Machine.

D. J. Daniels, Glendale High School, Glendale, Arizona: Advanced Placement Biology 2000, D. J. Daniels´ Glendale High Biology Page.
Still available via Internet Archive Wayback Machine.

Owen Kent Davis, Department of Geosciences, University of Arizona Tucson: Life on Earth. In this course, you will learn about biological systems, from molecular to global.

O. de Lange et al. (2021): 21st Century Opportunities for Amateurs in Biology Research. Open access, Integ. and Comp. Biol., 61: 2294–2305.

Senatskommission für Zukunftsaufgaben der Geowissenschaften der Deutschen Forschungsgemeinschaft (DFG):
Dynamische Erde – Zukunftsaufgaben der Geowissenschaften. 8.1 - Die Evolution von Atmosphäre und Ozeanen. In German
Still available through the Internet Archive´s Wayback Machine.

Senatskommission für Zukunftsaufgaben der Geowissenschaften der Deutschen Forschungsgemeinschaft (DFG):
Dynamische Erde – Zukunftsaufgaben der Geowissenschaften. 10.2 – Herkunft und Entwicklung des Lebens. In German.
Still available through the Internet Archive´s Wayback Machine.

Senatskommission für Zukunftsaufgaben der Geowissenschaften der Deutschen Forschungsgemeinschaft (DFG):
Dynamische Erde – Zukunftsaufgaben der Geowissenschaften. 10.5 – Extreme und unbekannte Habitate. In German.
Still available through the Internet Archive´s Wayback Machine.

S. Díaz and Y. Malhi (2022): Biodiversity: Concepts, patterns, trends, and perspectives. Free access, Annual Review of Environment and Resources, 47: 31-63.

! Theodosius Dobzhansky (1973): Nothing in Biology Makes Sense except in the Light of Evolution. The American Biology Teacher, 35: 125-129.

Encyclopedia of Earth. An electronic reference about the Earth, its natural environments, and their interaction with society. Go to: AP Environmental Science Chapter 5- The Biosphere. About organisms, populations and communities, ecosystems, biomes and the evolution of life. Snapshot taken by the Internet Archive´s Wayback Machine. More articles here.

M.J. Farabee, Estrella Mountain Community College, Phoenix, Arizona:
! On-Line Biology Book. Table of Contents. Introductory biology lecture notes.
Still available via Internet Archive Wayback Machine.

! M.J. Farabee, Estrella Mountain Community College Center, Avondale, Arizona: On-Line Biology Book. Introductory biology lecture notes.
Now available through the Internet Archive´s Wayback Machine.

Kathleen M. Fisher, Stacy Gomes, Susan Levine, Rebecca Smith & Robert Weeks: Biology Lessons for Prospecting and Practicing Teachers.
Now recovered from the Internet Archive´s Wayback Machine.

! A. Genre et al. (2020): Unique and common traits in mycorrhizal symbioses. In PDF, Nature Reviews Microbiology, 18, 649–660.
See also here.
Note figure 1: Major mycorrhizal types.
"... Mycorrhizas are among the most important biological interkingdom interactions, as they involve ~340,000 land plants and ~50,000 taxa of soil fungi
[...] During evolution, mycorrhizal fungi have refined their biotrophic capabilities to take advantage of their hosts as food sources and protective niches, while plants have developed multiple strategies to accommodate diverse fungal symbionts ..."

J.C. Ghildiyal (ed.; 2019):
Pteridology, Gymnosperms and Palaeobotany. Lecture notes, in PDF, Uttarakhand Open University, India.
With many black and white illustrations.
Palaeobotany part starts on PDF page 254.

Scott Gilbert, Department of Biology, Swarthmore College, Swarthmore:
Still available via Internet Archive Wayback Machine.
ZYGOTE. The major function of this website is to provide materials to supplement and enrich courses in developmental biology. While its chapter headings are those of a textbook, the learner is able to choose his or her own path through the different "exhibits". It is more like a museum than a book.

! The Global Biodiversity Information Facility (GBIF):
GBIF is an international network and data infrastructure funded by the world's governments and aimed at providing anyone, anywhere, open access to data about all types of life on Earth. Excellent!

Steven Goldsmith, Austin College, Sherman, TX:
Evolution, Behavior, and Ecology. and Systematics. For a fundamental understanding of the conceptual framework that biologists use to make sense of the complexity and diversity of organisms. Note e.g.:
Phylogeny. Powerpoint presentation.

Govindjee, Department of Plant Biology , University of Illinois at Urbana-Champaign, Urbana:
The Photosynthesis Page Govindjee. Note especially:
! Teaching Material.

Devens Gust, Chemistry and Biochemistry, Arizona State University, Tempe (page hosted by ASU Photosynthesis Center, Arizona State University, Tempe): Why Study Photosynthesis?
Still available through the Internet Archive´s Wayback Machine.

! S.B. Hedges and S. Kumar (2009): Discovering the Timetree of Life. PDF file, In: S.B. Hedges and S. Kumar (eds.): The Timetree of Life.
! See here.
These expired links are now available through the Internet Archive´s Wayback Machine.

! S.B. Hedges (2009): Life. PDF file, In: S.B. Hedges and S. Kumar (eds.): The Timetree of Life.
! See here.
These expired links are now available through the Internet Archive´s Wayback Machine.

Scott A. Heckathorn, Department of Environmental Sciences, University of Toledo, Ohio, USA:
Biodiversity lecture notes, Powerpoint presentations. This expired link is available through the Internet Archive´s Wayback Machine.

! J. Huang et al. (2021): The oxygen cycle and a habitable Earth. In PDF, Science China Earth Sciences, 64: 511–528. See also here.
! Note figure 1: The status of the oxygen cycle in Earth system science and its relationship with other biogeochemical cycles.
! Figure 2: The evolution of atmospheric O₂ and maximum organismal sizes through geological time.
! Figure 3: Sketch of the modern geologic oxygen cycle showing the principal sources and sinks.
! Figure 4: Reconstructed O₂ content during the Phanerozoic Eon.
! Figure 5: Global oxygen cycle in the modern Earth system.

Dafeng Hui, Department of Biological Sciences, College of Life & Physical Sciences, Tennessee State University, Nashville, TN:
Biol 4120 Principles of Ecology. Go to: Recap: Ecological Succession. Lecture notes, Powerpoint presentations.

! International Commission on Zoological Nomenclature: The International Code of Zoological Nomenclature (4th edition, 1999).

Kania´s Science Page, Lake Central High School, St. John, IN:
Biology Page. Lecture notes, Powerpoint presentations. See for instance:
The History of Life.
Evolution.
Ecology Introduction.

! John W. Kimball: John W. Kimball: Kimball´s Biology Pages. The pages represent an online biology textbook, arranged much like an index, alphabetically by topics. Excellent!

S. Kinnebrock and H. Bilandzic (2023): Stories about Villains, Mad Scientists and Failure. In PDF, start on PDF page 303. Routledge Studies in the Philosophy of Science. In: K. Zachmann et al. (eds): Evidence Contestation: Dealing with Dissent in Knowledge Societies.

A.H. Knoll (2012): Systems Paleobiology. In PDF. Still available via Internet Archive Wayback Machine. See also:
here (vimeo.com), or
there (YouTube).

Dana Krempels, Department of Biology, University of Miami, Coral Gables, FL: Evolution and Biodiversity. Lecture Notes.
Available from the Internet Archive´s Wayback Machine.

Richard Lees, United Kingdom: Biology Online. This Web site is ideal suited for high school students, or in general, avid learners or people surfing around the web. It starts at the basics, and covers a cross section of biological issues, which can educated an individual to Pre-University Standard.

! J. Lendemer et al. (2020): The Extended Specimen Network: A Strategy to Enhance US Biodiversity Collections, Promote Research and Education. Free access, BioScience, 70: 23–30.
Corrigendum: The Extended Specimen Network: A Strategy to Enhance US Biodiversity Collections, Promote Research and Education. Free access, BioScience, 70: 195.

! Jere H. Lipps, University of California, Museum of Paleontology, Berkeley, CA: The Decline of Reason? About science and anti-science.

I. Löbl et al. (2023): The Silent Extinction of Species and Taxonomists—An Appeal to Science Policymakers and Legislators. Free access, Diversity, 15, 1053. https://doi.org/10.3390/d15101053.
"... The science of taxonomy, albeit being fundamental for all organismic research, has been underfunded and undervalued for about two generations. We analyze how this could happen, particularly in times of a biodiversity crisis ..."
[...] Our suggestions are
[...] To significantly increase financial support and the number of paid non-term-limited positions in taxonomy in general and particularly in natural history museums
[...] To immediately revive taxonomic research and teaching at universities
[...] To focus digitization efforts on parts of collections
[...] To require natural history museums to focus on collection-based research ..."

J. Louys (2012; ed.): Paleontology in Ecology and Conservation. In PDF, Springer Earth System Sciences, DOI 10.1007/978-3-642-25038-5_3, See also here. Note especially:
! Starting on PDF page 1: Chapter 1 Paleontology in Ecology and Conservation: An Introduction (by J. Louys).
! Starting on PDF page 23: Chapter 3 Ecology Needs a Paleontological Perspective (by J.Louys, D.M. Wilkinson, and L.C. Bishop).
! Starting on PDF page 39: Chapter 4 Reconciling Scale in Paleontological and Neontological Data: Dimensions of Time, Space, and Taxonomy (by J.B. Bennington and M.F.J. Aronson).

! MAdLand — Molecular Adaptation to Land: Plant Evolution to Change.
The MAdLand community has made contributions to publicly available data resources for plant (evolutionary) biology and expanded the list of organismal systems accessible for research. Note the statement of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for the established Priority Programme SPP 2237. Worth checking out:
MAdLand Publications.
The interactive and downloadable Plant Evolution Poster.
Exhibition posters "Grün, Steine, Erde. Unsere Welt im Wandel" (in German, by M. Schreiber and S. Gould).

Stephen Marvel, Department of Biological Sciences, Lock Haven University, Lock Haven, PA: Inquiry into Biology. Lecture notes.
Now provided by the Internet Archive´s Wayback Machine.

Massachusetts Institute of Technology (MIT), Cambridge, MA: MIT Biology Hyertextbook.
This site is no longer being actively maintained; its contents have been removed.
See also here.

The Merck Manuals: Pronunciations.

A.J. McGowan (2011): Biodiversity: more than just how many species. In PDF, Palaeontology Online. See also here.

J.L. McGuire et al. (2023): The past as a lens for biodiversity conservation on a dynamically changing planet. Free access, PNAS, 120.

Microbe Notes.
Microbe Notes is an educational niche blog/website related to microbiology. Go to:
! Top and Best Biology Websites/Blogs of 2024 for Study Notes (by Sagar Aryal 2023).

! MIT OpenCourseWare, Massachusetts Institute of Technology (MIT), Cambridge, MA: This is a free and open educational resource for faculty, students, and self-learners around the world. Go to: Biology. Undergraduate, graduate, and postdoctoral training programs ranging from general biology to more specialized fields of study and research. Go to: Introduction to Biology (by Eric Lander, Robert Weinberg, Claudette Gardel and Andrew Chess). Lecture notes (video lectures) about the fundamental principles of biochemistry, genetics, molecular biology, and cell biology. Biological function at the molecular level is particularly emphasized and covers the structure and regulation of genes, as well as, the structure and synthesis of proteins, how these molecules are integrated into cells, and how these cells are integrated into multicellular systems and organisms. Media player software, such as QuickTime Player, RealOne Player, or Windows Media Player, is required to run the .mp3 files found on this course site.
See also here (video lectures).

Gilbert J. Muth, Pacific Union College, Angwin, CA:
Biological Foundations. Biological Foundations is the botany section of the a three quarter sequence in general biology for biology majors and pre-professional students. It contains
38 lectures with a (incomplete) supporting glossary, photographs, photomicrographs, diagrams, animations, video clips, self test and set of references.
Still available via Internet Archive Wayback Machine.

National Association of Biology Teachers (NABT), Warrenton, VA.
Recommended Resources.
NABT has created a searchable table of online Peer-Recommended Resources. You can filter by category and audience to get just what you need when you need it. Note escecially:
! Evolution.
! Ecology/Environment.
! General Biology.

National Council of Educational Research and Training (NCERT), New Delhi:
NCERT Books for Class 11 Biology PDF.

Carl R. Nave, Department of Physics and Astronomy, Georgia State University, Atlanta: HyperPhysics. HyperPhysics is an exploration environment for concepts in physics which employs concept maps and other linking strategies. Go to: Biology Concepts.

Peter Ommundsen, Selkirk College, Canada: Pronunciation of Biological Latin. Including taxonomic names of plants and animals. See also here (PDF file).

Dennis O'Neil, Palomar College, San Marcos, California: The Basic Principles of Genetics. An introduction to Mendelian Genetics.
Still available through the Internet Archive´s Wayback Machine.

Open Door Web Site: Biology. A reference source for both students and teachers. The site is constructed by teachers with the aim of making the web site available on-line for their students. Go to: Topic Chapters.

Larry Orr, Center for the Study of Early Events in Photosynthesis, and Govindjee, Departments of Biochemistry and Plant Biology and Center of Biophysics & Computational Biology, University of Illinois, Urbana: Photosynthesis and the Web: 2004. See also: What is Photosynthesis? Articles that discuss photosynthesis at varying degrees of complexity.

Michael Pidwirny, Department of Geography, Okanagan University College, Kelowna, British Columbia, Canada: FUNDAMENTALS OF PHYSICAL GEOGRAPHY. The main purpose of Physical Geography is to explain the spatial characteristics of the various natural phenomena that exist in Earth's hydrosphere, biosphere, atmosphere, and lithosphere. Go to: The Universe, Earth, Natural Spheres, and Gaia, and Introduction to the Biosphere. Easy to understand information.

! Plant Ontology Consortium (POC). The main objective of the POC is to develop, curate and share controlled vocabularies (ontologies) that describe plant structures and growth and developmental stages, providing a semantic framework for meaningful cross-species queries across databases. Go to: Search, or visit the
Plant Ontology Tutorials (Quicktime movies or Powerpoint slides).

! William K. Purves, David Sadava, Gordon H. Orians, and H. Craig Heller Life, The Science of Biology (Seventh Edition). The Companion Site. Interactive summaries, the glossary, animated tutorials and lots of flahcards (review figures).

Quizlet.com study tools:
! Search for Biology.

Radboud University, Nijmegen, The Netherlands: Virtual Classroom Biology. This website is an educational site, especially meant for secondary school students who like to have a first glance on teaching items of the Bio-science programs. One can find custom-made teaching material for courses from the biology training. Navigate from here. See especially:
The Microworld of Leaves.
Light microscopy techniques.
Electron microscopy (EM).

! Mark Ridley (2004): Evolution (Third edition). In PDF. 786 pages, Blackwell Publishing company. See likewise here (Google books), or there.
Note especially:
Chapter 1.3, "A short history of evolutionary biology", Start at PDF-page 33.
! Part 5, Macroevolution. Chapter 18, "The History of Life", Start at PDF-page 558.
About plant evolution note:
Chapter 3, "The Evidence for Evolution", Start at PDF-page 43.
Chapter 14, "Speciation", Start at PDF-page 416.
Chapter 19, "Evolutionary Genomics", Start at PDF-page 591.

Jose Sarukhan (Tinker Visiting Professors, Stanford University), Access Excellance, BioForum 4, "Theoretical Issues in Plant Biology": Biodiversity. Now available by the Internet Archive´s Wayback Machine.
BioForum is a series of lectures, presented by California Academy of Sciences, in which scientists share their research results with high school biology teachers.

George Sly, Union High School, Dugger, Indiana (Classrooms of the 21th Century):
Teaching Tropical Rainforest Biology.
Archived by the Internet Archive´s Wayback Machine.

National Museum of Natural History (NMNH) Smithsonian Institution: Resources for Teachers & Classrooms.

SpaceRef.com: NASA's astrobiology home page.

Francis F. Steen, Department of English, University of California at Santa Barbara: Can Matter Store Active Information? Landmarks in the history of genetics.

! W. Steffen et al, (2020): The emergence and evolution of Earth System Science. In PDF, Nature Reviews Earth & Environment, 1: 54–63.
See also here. "... ESS [Earth System Science] has produced new concepts and frameworks central to the global-change discourse, including the Anthropocene, tipping elements and planetary boundaries. Moving forward, the grand challenge for ESS is to achieve a deep integration of biophysical processes and human dynamics to build a truly unified understanding of the Earth System ..."

Swedish Museum of Natural History, Stockholm:
Natural science in schools, Diversity of Life. Teaching material, in PDF.

Kurt Stüber, Max Planck Institut für Züchtungsforschung, Köln: www.biolib.de. This is a collection of more than 401 historic and modern biology books. Go to: List of books sorted by categories

! Roger Summons and Tanja Bosak, MIT Opencourseware, Massachusetts Institute of Technology: Geobiology. An introduction about the parallel evolution of life and the environment. Life processes are influenced by chemical and physical processes in the atmosphere, hydrosphere, cryosphere and the solid earth. In turn, life can influence chemical and physical processes on our planet. This course explores the concept of life as a geological agent and examines the interaction between biology and the earth system during the roughly 4 billion years since life first appeared. Go to:
Lecture Notes. See especially: Theories Pertaining to the Origin of Life. In PDF.

! Bruce H. Tiffney, UC Santa Barbara: What is Science? Tracking the course of evolution.

TimeTree (Institute for Genomics and Evolutionary Medicine, Center of Biodiversity, Temple University, Philadelphia, PA). TimeTree is a public knowledge-base for information on the evolutionary timescale of life.
Go to: Resources.

Tinu Thakore´s Site, Herricks High School, New Hyde Park, NY: Living Environment Course Resources. Powerpoint and PDF files, e.g.
What is Science.
Photosynthesis.
Evolution.
Ecology.

! Topics For Seminar.
Topics For Seminar PPT's contents and Seminar Reports are collected from various public domains available free on the internet.
! Biology Topics for Presentation & Research.
100+ Interesting Biology Presentation Topics with PPT.

! The Tree of Life Web Project (ToL). This project is a collaborative effort of biologists from around the world. On more than 3000 World Wide Web pages, the project provides information about the diversity of organisms on Earth, their evolutionary history (phylogeny), and characteristics.

The Biology Project (an interactive online resource for learning biology), University of Arizona, Tucson: Prokaryotes, Eukaryotes, & Viruses Tutorial. The goal of this exercise is to introduce to the kinds of cells that make up all living systems (Prokaryotes, Eukaryotes), and to contrast cells with viruses.

School of Integrative Biology, School of Molecular & Cellular Biology, University of Illinois, Urbana-Champaign: Life Sciences.
Courses with web-based info (lecture notes, exams, quizzes, links, lab exercises): life sciences, biophysics, cell and structural biology, cell and structural biology, ecology, ethology and evolution, entomology, microbiology, molecular and integrative physiology, plant biology.
Still available via Internet Archive Wayback Machine.

Sloan Center for Asynchronous Learning Environments, University of Illinois at Urbana-Champaign, Urbana: Virtual Cell. This is a collection of still images, texts and movies covering the structure and functioning of a typical plant cell.

Biology Department, Western Washington University, Bellingham, Washington:
Biology 102. Lecture notes.
Plant Evolution. Powerpoint presentation.

Wayne's Word (by Wayne P. Armstrong, Palomar College,San Marcos, CA):
The Five Kingdoms Of Life. Brief information about the five major kingdoms, including the Monera, the Protista (Protoctista), the Fungi, the Plantae, and the Animalia.

Wayne's Word An Online Textbook Of Natural History (Wayne P. Armstrong, alias Mr. Wolffia, Palomar College):
Biology. Lecture notes.
The Five Kingdoms Of Life. Brief information about the five major kingdoms, including the Monera, the Protista (Protoctista), the Fungi, the Plantae, and the Animalia.

Q.D. Wheeler et al. (2012): Mapping the biosphere: exploring species to understand the origin, organization and sustainability of biodiversity. In PDF, Systematics and Biodiversity, 10.

Wikipedia, the free encyclopedia:
AP Biology
Origin of life.

Wikibooks, the open-content textbooks collection:
General Biology.

Stephen M. Wolniak, Department of Cell Biology & Molecular Genetics, University of Maryland: An Introduction to Mitosis. Mitosis is the process that facilitates the equal partitioning of replicated chromosomes into two identical groups.

! The World of Teaching.
Over 1000 powerpoint presentations made by teachers are available for download.
Free Biology powerpoints. See e.g.:
Botany, Photomicrographs, Plant Tissues Lecture notes, Powerpoint presentation.