Which of the following most likely happens when we exercise? a. the heart rate slows down because the blood vessels have less blood to circulate. b. the heart rate slows down because the blood vessels have more blood to circulate. c. the heart pumps faster so that the blood vessels can carry more oxygen to some cells. d. the heart pumps faster so that the blood vessels can carry more carbon dioxide to some cells.

The observations of hooke and van leeuwenhoek documenting the existence of microscopic cells formed the basis of what important theory? a. the cell theory stating that all living things are composed of cellsb. the theory of spontaneous generation, which held that life forms could arise spontaneouslyc. the theory of chemotherapy, or use of antimicrobials to destroy pathogenic organismsd. the germ theory of disease and causative agents

The kind of fertilization found in the majority of aquatic animals is (internal or external) fertilization.

Aprocedure done under controlled conditions to test a hypothesis is an inquiry.