At what tropic level do the killer and whales primarily feed

Control of the body is accomplished by which of the following body systems? nervous system and circulatory system endocrine and repertory system circulatory and respiratory systems nervous system and endocrine systems

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins

For mendels studies, why was it important that his subjects, pea plants, could reproduce quickly and and produce many offspring?