Gametogenesis, Biology

The process by which gametes are produced in the gonads is known as gametogenesis.

The process of formation of male gametes or sperm is known as spermatogenesis is of great significance be- cause the gamates are the only link between the generations.

Their nuclear DNA is the depository of all those genetic informations that are needed in the development of new organism.

In monoecious or hermaphroditic animals both male and female gametes are produced in the same individual.

In dioecious animal, the sperm and ova are formed in different individual, but in same species.

ORIGIN OF PGC IN INVERTEBRATE ANIMAL

In invertebrate animal PGC originate in embryonic development. e.g. Ascaris & drosophila.

ORIGIN OF PGC IN VERTEBRATE ANIMAL

In vertebrate animal PGC originated due to separation of germ plasm through somatic plasm.

PGC determined in vertebrates as follows -

1.       In fishes - PGC originate by endoderm and establish in developing gonads.

2.       In amphibians - Specific cytoplasm present in vegital pole of egg. This cytoplasm form the PGC.

3.       In reptiles and aves - PGC originated outside the gonads. eg. in chick embryo PGC originate posterior part of disc and the migrate toward the anterior part and carry through blood circulation in the developing gonads.

4.       In mammals - The PGC are formed near the yolk sac from the endoderm (Gonads formed from mesoderm)

Posted Date: 10/3/2012 7:20:08 AM | Location : United States







Related Discussions:- Gametogenesis, Assignment Help, Ask Question on Gametogenesis, Get Answer, Expert's Help, Gametogenesis Discussions

Write discussion on Gametogenesis
Your posts are moderated
Related Questions
BLOOD SAMPLING : In blood sampling, the skin is deliberately punctured in order to take a blood sample for analysis. If this is done carelessly, it is easy for microorganisms eith

The secretary coil fills the lumen with a NaCl solution that is isotonic with the blood plasma. As this solution moves upward through the reabsorptive duct, NaCl is reabsorbed into

What are the characteristics of cardiac muscle that allow it to be highly resistant to fatifue?

Particulate Theory (i)         Maupertuis (1689-1759) proposed that the body of each parent give rise to minute particles. (ii)         In sexual reproduction, these particl


What is the evolutionary advantage of the occurrence of sperm cells and larval stage in the life cycle of sponges? The sexual reproduction in sponges, in addition to contributi

How boron affect the the synthesis of proteins ? Inadequate availability of boron tends to increase the loss of phosphorus from plant roots and also affects the synthesis of pro

Concerning the nitrogen-containing bases that participate in nucleotides, what is the difference among DNA and RNA? In DNA nucleotides can be formed of adenine (A), thymine (T)

Cell-mediated immunity:  The immune reaction directed against the body cells which have been infected by viruses and bacteria; and are controlled by T cells.

Illustrate the functioning of comprehensive model 1) Provide continuity in understanding developmental progress, or lack thereof, in those disorders that affect neurological de