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):
- Immediately after penetration of a spermatozoon into the egg, the cortical reaction initiates to prevent further entry of spermatozoa.
- Chemical substances found in the cortical granules are released in between the plasma membrane and vitelline membrane.
- These substances fuse with the vitelline membrane to form the fertilization membrane.
- 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.