For normal fertility what percent of the sperm in ejaculate must exhibit vigorous motility ?

(1) 20

(2) 30

(3) 40

(4) 60

The function of male sex accessory ducts and glands are maintained by:

1. Hypothalamic releasing hormone

2. Pitutary gonadotropins

3. Adrenal cortex steroids

4. Testicular androgens

The division of primary oocyte results in:

1. unequal cells a smaller haploid secondary oocyte and a larger diploid polar body

2. unequal cells a larger haploid secondary oocyte and a smaller haploid polar body

3. unequal cells a smaller diploid secondary oocyte and a larger haploid polar body

4. equal cells - a haploid secondary oocyte and a haploid polar body

The correct sequence of the various phases of a typical menstrual cycle is:

(1) Menstrual $\stackrel{ }{\to }$ Follicular $\stackrel{ }{\to }$ secretory $\stackrel{ }{\to }$ Ovulatory

(2) Menstrual $\stackrel{ }{\to }$ Follicular $\stackrel{ }{\to }$ Ovulatory $\stackrel{ }{\to }$ secretory

(3) Ovulatory $\stackrel{ }{\to }$ Follicular $\stackrel{ }{\to }$ secretory $\stackrel{ }{\to }$ Menstrual

(4) Menstrual $\stackrel{ }{\to }$ secretory $\stackrel{ }{\to }$ Follicular $\stackrel{ }{\to }$ Ovulatory

LH surge:

During pregnancy:

1. All events of menstrual cycle stop and there is no menstruation

2. Events of menstrual cycle continue but there is no menstruation

3. Events of menstrual cycle contInue but there is menstruation only in the first trimester

4. All events of menstrual cycle stop and there is menstruation only in the first trimester

In the absence of fertilization, corpus luteum:

1. Stops secreting progesterone but increases the secretion of estrogen

2. Stops secreting estrogen but increases the secretion of progesterone

3. Increases the secretion of both progesterone and estrogen

4. Degenerates

What ensures that only one sperm can fertilize the ovum?

1. Corona radiata

2. Ground substance around ovum

3. Zona pellucida

4. Acrosome

In humans, the sex of the baby is determined:
1. At the time of fertilization and by the father
2. At the time of fertilization and by the mother
3. At the time of implantation and by the father
4. At the time of implantation and by the mother

During pregnancy the levels of thyroxin:

1. Increase several folds in maternal blood

2. Increases several folds in fetal blood

3. Decreases several folds in maternal blood

4. Decreases several folds in fetal blood