After being released the secondary oocyte must be fertilized within:

1. 1 hour.

2. 12 hours.

3. 24 hours.

4. 72 hours.

Testosterone secretion before birth is due to:

1. FSH

2. GnRH

3. HCG

4. LH

The release of the sperms from the ampulla of the vas deferens is called:

1. erection.

2. emission.

3. ejaculation.

4. orgasm.

Identify the incorrectly matched pair [with respect to a 28 days cycle]:

1. beginning of menstrual flow - day 1

2. ovulation - day 14

3. LH surge - day 21

4. beginning of proliferative phase - day 5

Which part of the blastocyst develops into the embryo proper?

1. inner cell mass.

2. trophoblast.

3. blastocele.

4. yolk sac.

Milk secretion by mammary glands is under the control of:

The epidermis and the dermis of the skin develops respectively from embryonic:
1. ectoderm, endoderm
2. ectoderm, mesoderm
3. endoderm, mesoderm
4. endoderm, ectoderm

Identify the organ system in humans that is derived from all the three embryonic germ layers:
1. cardiovascular system.
2. digestive system.
3. endocrine system.
4. muscular system.

Lactation after child birth is possible due to decrease in the secretion of:
1. HCG
2. oxytocin
3. FSH and LH
4. estrogen and progesterone

The initial phase of the cortical reaction leads to:
1. slow block to polyspermy
2. fast block to polyspermy
3. formation of pronuclei
4. completion of acrosome reaction