Erin had both her left ovary and her right uterine tube removed surgically at age 17 because of a cyst and a tumor in these organs. Now, at age 32, she remains healthy and is expecting her second...

Erin had both her left ovary and her right uterine tube removed surgically at age 17 because of a cyst and a tumor in these organs. Now, at age 32, she remains healthy and is expecting her second child. How could Erin conceive a child with just one ovary and one uterine tube, widely separated on opposite sides of the pelvis like this?

Indicate whether each of the following statements is describing (a) cleavage or (b) gastrulation.