Which of the following mechanisms is not used to propel lymph through lymphatic vessels? a. gravity b. small heart-like pumps c. the milking action of muscles d. pulmonary motion

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

Why zebra fish experience similar genetic disease as human

Which in counting the age of a tree? a.rings seen in the stemb. height of the treec. width of the tree