This sites is an online text. It covers all aspects of general biology. It is searchable by term or alphabetically. Pages include text and images. Directions for use of the site are clear.

Topics include:
Animals; Caenorhabditis elegans: a model organism, Drosophila melanogaster, Invertebrates, Vertebrates, Zebrafish.
Behavior: Innate Behavior, Circadian Rhythms, Honeybee Navigation, Learned Behavior, Magnetoreceptors, Avoiding Predation, Pheromones, Taxes.
Biochemistry: ATP, Bioluminescence, Cellular respiration, Chemiosmosis, Enzymes, G proteins,
Gels, Glycolysis, Metabolism, Photorespiration, Photosynthesis, Reactive oxygen species (ROS), Second messengers, Serine proteases, The Urea cycle.
Cancer: Ames Test, Angiogenesis, Burkitt's Lymphoma, Immunotherapy of cancer, The LD50 test, Mutations, Oncogenes, Radiation, Tumor Suppressor Genes.
Cell Biology: Active transport, Apoptosis, Cell Cycle, Cell Junctions, Cell membranes, Cell signaling, Chloroplasts, Chromosomes, Cilia, Cytoskeleton, actin microfilaments, intermediate filaments, microtubules, Endocytosis and Exocytosis, Facilitated diffusion and membrane channels, Fluorescence-activated cell sorter (FACS), G proteins, Golgi apparatus, Glycolysis, Lysosomes and Peroxisomes, Mitosis and Meiosis, Nucleus, Polyploidy, The Proteasome, Ribosomes, Second messengers, Sex Chromosomes, Stem cells, Telomeres.
Chemistry: Acids and bases, Aluminum, Bond Energy, Calcium, Dioxin, Electronegativity: and types of chemical bonds., Elements and atoms, Free energy, Hydrogen bonds, The International System of Units, Mixtures and compounds, Molecular weight and the mole, Parts per million (PPM), etc., pH, Prions, Redox potentials
Diversity of Life: Ciliates, Fungi, Neurospora crassa, Plants, Protists, Taxonomy, Yeast,
DNA and RNA: Ames Test for mutagens, Antisense Oligodeoxynucleotides and their therapeutic potential, Antisense RNA, Base Pairing: in DNA and RNA, DNA chips, DNA recombination in meiosis, DNA Repair, DNA Replication, DNA sequencing by the dideoxy method, DNA vaccines, The Double Helix: of DNA, Endoreplication, Expressed Sequence Tags, Gene Expression in Prokaryotes, Gene Therapy: methods and prospects and recent advances, Genetic recombination in bacteria, The Genetic Code, Genome Sizes, Harlequin chromosomes, The Hershey-Chase Experiments, The Human Genome Projects, Imprinted Genes, Insulators between genes, The Meselson-Stahl Experiment, Molecular polymorphisms, Mutations: causes and significance, Mutations: testing for mutagenic chemicals in bacteria and in mice, Nucleotides, Operons, Palindromes, Polymerase chain reaction (PCR), Polyploidy, Promoters, Radiation and its effect on DNA, Recombinant DNA and Gene Cloning, Restriction Enzymes: the tools upon which molecular biology and biotechnology depend, Restriction Fragment Length Polymorphisms (RFLPs): and their use in medical diagnosis and law enforcement, Ribosomal RNA (rRNA) gene cluster, Ribozymes, RNA editing, Steroid Response Elements: how steroid hormones regulate gene expression, Telomeres, Testing for mutagens in mice, Transcription of DNA, Transcription factors, isolating, footprinting, Translation of messenger RNA, Transduction in bacteria, Transformation in bacteria, Transgenic Animals, Transgenic Plants, Transposons: mobile genetic elements, The Tryptophan Repressor: how the presence of tryptophan shuts down the genes needed for its synthesis. Includes a stereo view of the molecule bound to the DNA of the Trp operon.,
Ecology: Acid Rain, Air pollution, Biological control of pests, Biomagnification of pesticides, Biomes, Carbon cycle, Chlorination, MX, and the Law of Unintended Consequences, DDT in food chains, Dioxin, Food chains and food webs, Freshwater ecosystems, Insecticides, Marine ecosystems, Net Productivity of ecosystems, Nitrogen cycle, Nitrogen fixation, symbiotic, Ozone, Population Biology and the Human Population