What ensures that only one sperm can fertilize the ovum?

1. Corona radiata

2. Ground substance around ovum

3. Zona pellucida

4. Acrosome

Sperm has several components out of which the function of the acrosome is to:

Capacitation occurs in

(1) rete testis

(2) epididymis

(3) vas deferens

(4) female reproductive tract

Fertilisation in humans is practically feasible only if

1. the ovum and sperms are transported simultaneously to ampullary region of the fallopian tube
2. the ovum and sperms are transported simultaneously to ampullary region of the cervix
3. the sperms are transported into cervix within 48 hrs of release of ovum in uterus
4. the sperms are transported into vagina just after the release of ovum in fallopian tube

In human females, meiosis-II is not completed until 

1. Puberty

2. fertilization 

3. Uterine implantation 

4. birth 

The second maturation division of the mammalian ovum occurs

1. shortly after ovulation before the ovum makes entry imto the Fallopian rube

2. until after the ovum has been penetrated by a sperm

3. until the nucleus of the sperm has fused with that of the ovum

4. in the Graafian follicle following the first maturation division

Which one of the following statements about morula in humans is correct?

1. It has almost equal quantity of cytoplasm as an uncleaved zygote but much more DNA

2. It has far less cytoplasm as well as less DNA than in an uncleaved zygote

3. It has more or less equal quantity of cytoplasm and DNA as in uncleaved zygote

4. It has more cytoplasm and more DNA than an uncleaved zygote 

Acrosome reaction in sperm is triggered by

(1) capacitation

(2) release of lysin

(3) influx of Ca++

(4) release of fertilizin

Assertion   :       There is generally monospermy in most of animals.

Reason      :       Vitelline membrane of ovum checks polyspermy.