In the heart dissection you performed, you noted the muscular walls of the ventricles. The walls of the atria, however, were much thinner. Why do you think the ventricular walls are so much thicker than the atrial walls?

Epinephrine is a hormone released from the adrenal gland of the body, most often in a stressful situation. it is known as the "fight-or-flight" hormone. one way that it causes a response in the body is to activate receptors on muscle cells. where are these cellular receptors located? a. on the cell membrane b. in the nucleus c. on the cell wall d. around the mitochondria

When proteins are being produced by a cell, scientist say that the genes are question 2 options: activated turned off replicated deactivated

You are observing different types of cells in your science lab. one cell has many chloroplasts. what is the most likely function of this cell? a. energy production b. photosynthesis c. reproduction d. digestion