ch 28

Question 1

1. Capacitation : event/process

Answer 1

thinning of the acrosome 7-10 hours

Question 2

2. Penetration : event/process

Answer 2

spermatozoa burrows through the layers around the secondary oocyte
1. Corona radiata- outer layer
2. Zona pellucida - inner layer

Question 3

3. Fertilization : event/process

Answer 3

fusion of nuclei
Result is the zygote stage (46 chromosomes); monozygotic twins - identical
dizygotic twins - fraternal

Question 4

4. Cleavage : event/process

Answer 4

a. A rapid cell division with a increase in cell number and a decrease in cell size
b. Results in the morula stage (16-32 cells- looks like a berry)

Question 5

5.Differentiation : event/process

Answer 5

a. Cells go from unspecialized to specialized cells
b. results in a blastocyst stage made of two parts

Question 6

6. Implantation : event/process

Answer 6

a. Occurs after 6 day trip to the uterus - embryo attaches to the endometrium

Question 7

7. Gastrulation : event/process

Answer 7

a. This is the formation of the germ layers in the embryo that give rise to organs b. Ectoderm - becomes the nervous system and the epidermis
c. Mesoderm - becomes muscle, bone and just about everything
d. Endoderm - becomes the inner linings with the body

Question 8

8. Embryonic Membranes in a one month embryo

Answer 8

a. Yolk sac - supplies nutrients to embryo
b. Amniotic sac - circles the embryo filled with fluid for protection c. Chorionic villi- (from the trophoblast) becomes the placenta