General Biology

acid adapted algae amino antheridium archegonium arteries bacteria become birds blood body bone Botany brain called capillaries carbon dioxide carpels cavity cell wall chemical chromosomes coelom compounds consists contains cycle cytoplasm digestive disease divided division dorsal earthworm electrons embryo energy epidermis evolution example female fibers fish flowering plants flowers food materials fossils frog gametes gametophyte gene gills glands hydrogen hydronium includes individuals insects intestine larvae layer leaves liver living Macmillan Company male mammals membrane metameres molecules moss mouth muscles mutations nerve neurons nucleus occur organs ovary oxygen pairs Paleozoic parasites pass pharynx phloem photosynthesis phylum plants and animals plasma plasma membrane pollen portion posterior proteins protoplasm reproduction root seed shell side species sperm spores sporophyte stage stem structure substances surface tion tissue tube usually veins ventral vertebrates vessels worm xylem zygote