Topics: Phylum Echinodermata, Echinodermata, water vascular system, Asteroidea, ophiuroidea

Topics: Digestion, Digestive system

Topics: Nervous system, Neurochemicals, Reflex actions, Reflex arc, Synapse, Action potential, Resting Potential, Nerve Impulse, spinal cord, brain, neurons

Topics: Blood Composition, Plasma makeup, Plasma, Albumins, Globulins, Clotting proteins, Red Blood Cells, White Blood Cells, Platelets, Blood Coagulation, Blood Clotting, Vascular spasm, Vasoconstriction, Platelet Plug, Fibrin, ABO Group System, Capillaries, Veins, Venules, Heart

Topics: Agama, Reptilia, Squamata, Sauria, Serpentes, Amphisbaenia, Chelonia

Topics: Jaw, fin, fish, Chondrichtyes, Tilapia, Sarcopterygii

Topics: Rhodopsin, ommatidium, Ommatidia, rhodopsin, rhabdome, mosaic picture, Nocturnal insect, crepuscular insect, diurnal insect, Retinal Physiology, Retinal organization, Phototransduction, Molecular cascade, metabotropic receptor, ionotropic receptor, Myopia, astigmatism, amacrine cell, bipolar cell, optic chiasm