During the development of most animals, cleavage leads to __________.

Which of the following extraembryonic membranes functions in gas exchange and encloses a chamber for the deposition of wastes of a bird embryo?

In mammals, the __________ facilitates implantation in the uterine wall.

Evidence suggests that folic acid may help prevent the development of spina bifida, a common disabling birth defect. It is recommended that women increase their folic acid intake during pregnancy, especially in the first three months. Why is the timing of the folic acid intake relevant?

If you wanted to examine the extraembryonic membranes surrounding a lizard or mouse embryo, you would first have to cut through which of the following to see all the others?

Which of the following correctly lists the embryonic stages in the order that they develop?

The cortical reaction of sea urchin eggs functions directly ina. the formation of a fertilization envelope.b. the production of a fast block to polyspermy.c. the generation of an electrical impulse by the egg.d. the fusion of egg and sperm nuclei.

Which of the following is common to the development of both birds and mammals?a. holoblastic cleavageb. epiblast and hypoblastc. trophoblastd. gray crescent

The archenteron develops intoa. the mesoderm.b. the endoderm.c. the placenta.d. the lumen of the digestive tract.