Tag: human fertilization

Questions Related to human fertilization

Sexually transmitted diseases can be prevented by using condoms.

  1. True

  2. False


Correct Option: A
Explanation:
  • Condoms are the barrier method of birth control. Use of condoms block the sperm from entering the uterus. 
  • Sexually transmitted diseases can be prevented by using condoms as they make a physiological barrier between two individuals and prevents the entry of sperm into the female body. 
  • Thus, the correct answer is option A.

Fertilization of egg takes place in uterus.

  1. True

  2. False


Correct Option: B
Explanation:

Fertilization is the fusion of male (sperm) and female gametes (ovum) and it takes place in the Fallopian tube. 
Therefore, the correct answer is option B.

If there is no formation of egg cell during the development of ovule, then after fertilization which of the following structure will not develop?

  1. Embryo

  2. Endosperm

  3. Seed

  4. Fruit


Correct Option: A
Explanation:

After fertilization in plant, ovule develops into the seed.  Fertilized egg get segmented and lined by the cell-membrane which forms plant-embryo. Thus, the correct answer is option A.

What happens during fertilization in humans after many sperms reach close to the ovum?

  1. Secretions of acrosome help one sperm enter cytoplasm of ovum through zona pellucida

  2. all sperms except the one nearest to the ovum lose their tails.

  3. cells of corona radiata trap all the sperms except one

  4. only two sperms nearest the ovum penetrate zona pellucida.


Correct Option: A
Explanation:

During the process of fertilisation of the male and the female gametes (i.e the sperm and the egg) in humans, the sperm cells reach the egg, binds through the corona radiata and reach the zona pellucida layer of the egg. Here a molecule on the sperm binds with a glycoprotein in the zona pellucida layer of the egg. This causes the acrosome to burst, releasing an enzyme that helps the sperm cells to cross the zona pellucida. Now the cortical granules in the secondary oocyte release their content. this causes the zona pellucida to cross-link and harden, thus preventing the fertilisation of the egg by more than one sperm by preventing the entry of the sperm. Therefore, only a single sperm cell penetrates the zona pellucida. So, the correct option is 'Secretions of acrosome help one sperm enter the cytoplasm of ovum through zona pellucida'.

For erection and ejaculation to occur.

  1. There must be sufficient blood hydrostatic pressure leading to erectile tissue

  2. The parasympathetic and sympathetic branches of the nervous system must be properly functioning

  3. The urinary sphincters must be closed

  4. All of the above


Correct Option: B

Which of the following would be the correct path of a sperm on its way to fertilize an egg?
(i) Urethra
(ii) Epididymis
(iii) Vagina
(iv) Oviduct
(v) Vas deferens

  1. (i), (ii), (iii), (v), (iv)

  2. (i), (iii), (iv), (v), (ii)

  3. (ii), (i), (iii), (iv), (v)

  4. (ii), (v), (i), (iii), (iv)


Correct Option: D
Explanation:

  • Sperms are produced in seminiferous tubules.
  • From seminiferous tubules, they pass via seminiferous tubules-------> rete testis------> vasa efferentia--------> epididymis--------> vas deferens----------> urethra.
  • After ejaculation in the vagina, they pass through cervix and uterus to finally reach oviduct.
So, the correct option is '(ii), (v), (i), (iii), (iv)'.

At the time of fertilization

  1. First maturation division is completed

  2. Embryo is formed

  3. Second maturation division is completed

  4. First polar body is formed.


Correct Option: C
Explanation:

When the sperm cell penetrates into the ovum, second maturation division occurs.

So the correct option is 'Second maturation division is completed.'

Fertilization in humans is practically feasible only if

  1. The sperms are transported into cervix within $48$ hours of release of ovum in uterus

  2. The sperms are transported into vagina just after the release of ovum in fallopian tube

  3. The ovum and sperms are transported simultaneously to ampullary-isthmi junction of fallopian tube

  4. The ovum and sperms are transported simulatenously to ampullary-isthmi junction of cervix.


Correct Option: A
Explanation:

Fertilization in humans is practically feasible only if the sperms are transported into the cervix within 48 hours of the release of an ovum in the uterus. This is because the ovum is present in the fallopian tube in this duration and starts degrading after this.

So, the correct answer  is 'The sperms are transported into cervix within 
4848 hours of the release of the ovum in uterus'.

In human beings, after fertilisation, the structure which gets embedded in the wall of uterus is

  1. Ovum

  2. Embryo

  3. Blastocyst

  4. Zygote


Correct Option: C
Explanation:

After fertilization zygote is formed. Zygote start moving towards uterus and initial development takes place. Zygote enters the uterus on 3rd day in morula stage and later develops into blastocyst that implants in uterus wall. Thus, the correct answer is option C.