How does the heart keep the blood flowing throughout the body? A: It contracts and relaxes
B: It inflates and deflates
C: It inhales and exhales
D: It opens and closes

What feature of cell theory is best demonstrated in the image

Why was mendel's work not accepted at the time? o a. his results were false. o b. he did not repeat his experiments. o c. he did not have any data. o d. his results were surprising,

The cluster of developing cells from conception until birth is called an