In the cardiac cycle,
a. the right atrium and the right ventricle contract simultaneously.
b. the two atria relax while the two ventricles contract.
c. the left atrium contracts before the right atrium.
d. all four chambers of the heart contract at the same time.
e. all four chambers of the heart are in systole at the same time.

Maria wanted to grow a fern in her backyard. acting on a suggestion from a friend, she collected brown dots from the underside of a fern's leaves and then potted them. after a few days, maria saw small fern leaves erupting from the pot. which statement explains this phenomenon? a. the fern transitioned from gametophyte generation to sporophyte generation. b. the fern grew as a result of mitosis. c. the fern transitioned from sporophyte generation to gametophyte generation. d. the fern grew to be genetically identical to its parent plant.

Which of the following is an effect of the uneven heating of the earth by the sun? a sea breeze a land breeze a convection current all of the above

Explain how the parts of the peripheral nervous system work with the central nervous system to produce a response to the stimulus