In the alternation of generations life cycle the spore undergoes mitosis to become a
a. gametophyte.
b. sporophyte.
c. spore.
d. gamete.

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.