RBSE Solutions for Class 12 Biology Chapter 32 Man-Fertilization

Rajasthan Board RBSE Class 12 Biology Chapter 32 Man-Fertilization

RBSE Class 12 Biology Chapter 32 Multiple Choice Questions

Question 1.
Significance of fertilizin and antifertilizin in fertilization is –
(a) Attract gametes
(b) Protection of spermatozoa
(c) attachment of the sperms on the ovum surface
(d) All of the above
Answer:
(c) attachment of the sperms on the ovum surface

Question 2.
Fertilization is –
(a) Fusion of male and female pronuclei
(b) Fusion of two gamets
(c)

(d) All of the above
Answer:
(c)

Question 3.
Which part of sperm head comes in the contact with egg at the time of fertilization?
(a) Acrosome
(b) Acromegaly
(c) Acronis
(d) Anterior lobe
Answer:
(d) Anterior lobe

Question 4.
An enzyme secreted by the anterior lobe of sperm is –
(a) Hyaluronidase
(b) Pepsin
(c) Carboxylase
(d) D. Hydronidase
Answer:
(a) Hyaluronidase

Question 5.
Capacity for fertilization appears in the human sperm when sperms reach in the vagina. This activity is called –
(a) Cortical reaction
(b) Capacitation
(c) Acrosome reaction
(d) Meeting of sperm and ovum
Answer:
(b) Capacitation

Question 6.
The substances for energy conservation during sperm motility are –
(a) Androgamone – I
(b) Androgamone – II
(c) Gynogamone – I
(d) Gynogamone – II
Answer:
(a) Androgamone – I

Question 7.
Site of fertilization in female human is –
(a) Vagina
(b) Seminal vesicles
(c) Uterus
(d) Fallopian tubes
Answer:
(d) Fallopian tubes

Question 8.
Fertilizin is secreted by –
(a) Ovum
(b) Spermatid
(c) Graafian follicle
(d) Ovary
Answer:
(a) Ovum

Question 9.
Spermatozoan moves by –
(a) Tail
(b) Head
(c) Acrosome
(d) Middle part
Answer:
(a) Tail

Question 10.
Development of an unfertilized egg is called –
(a) Transformation
(b) Metamorphosis
(c) Morphogenesis
(d) Parthenogenesis
Answer:
(a) Transformation

RBSE Class 12 Biology Chapter 32 Very Short Answer Type Questions

Question 1.
Who has given the concept of fertilizin?
Answer:
F.R. Lillie.

Question 2.
Where fertilizin is present?
Answer:
The surface of the ovum.

Question 3.
Who has studied acrosome reaction?
Answer:
Colwin, 1963.

Question 4.
Define fertilization.
Answer:
The fusion of male gamete (sperm) and female gamete (ovum) is called fertilization.

Question 5.
What is Amphimixis?
Answer:
This process involves karyogamy (fusion of male and female pronuclei) and plasmogamy (fusion of cytoplasm of ovum and sperm).

Question 6.
What is parthenogenesis?
Answer:
Development of ovum without fertilization is called parthenogenesis. Neither the sperms activates the ovum nor there is amphimixis.

Question 7.
What is ovum activation?
Answer:
Cortical Reaction (Activation of Ovum):

1. Immediately after penetration of a spermatozoon into the egg, the cortical reaction initiates to prevent further entry of spermatozoa.
2. Chemical substances found in the cortical granules are released in between the plasma membrane and vitelline membrane.
3. These substances fuse with the vitelline membrane to form the fertilization membrane.
4. Following metabolic activities are initiated in the ovum after penetration of sperm:
   • Fertilization cone is formed on the egg surface.
   • Fertilization membrane is formed by the vitelline membrane and cortical granules.
   • Permeability of the plasma membrane is increased.
   • Rate of protein synthesis is increased.
   • Mitotic divisions start in the fertilized egg.

Question 8.
What is capacitation?
Answer:
The gaining of capacity by the sperm to fertilize an ovum is called capacitation.

RBSE Solutions for Class 12 Biology