Biology and Human Progress

alcohol ameba baby bacteria birds blood vessels body bones brain breathing breed breeder cancer carbon dioxide cause chemical chlorophyll chromosomes color corn Cour Courtesy U. S. Describe develop digestive dinosaurs diphtheria disease drug embryo experiment Explain eyes fertilization fish flowers forests fossil frog fruit genes germs glands green GROUP DISCUSSION grow habit heart hemophilia hormone human important insects juice kidney layers leaf living things look lungs mammals meat membrane microscope milk millions muscle mutations nucleus organs oxygen parents person pistil plants and animals polio pollen PROBLEM produce protein protozoa red blood cells reflex result rock root Schick test scientists seeds shell skin small intestine soil sperm cell spores starch stomach substances sugar SUMMARY QUESTIONS tesy tiny tissue traits trees tube tuberculosis vaccine Vitamin D vitamins wheat Wildlife X chromosome