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
Q. Explain Continuous full - thickness incision? Continuous full - thickness incisions are indicated for a variety of situations outlined below. This type of incision may be us

define the pattern of cleavage i all aspects

Are fruits always the flesh part of the "fruits"? Is the edible part of the onion a fruit? In some so-called fruits the actual fruit is not the flesh part. For instance, the fl

Population Density - Biological Stress You are aware of what might follow an uncontrolled growth of human population. There will be competition for common consumables and for

Is it correct to consider water decomposition by the action of light the basis of the photosynthesis process? Besides ADP photophosphorylation, photic energy is also responsibl

Agriculture - Degradation of Ecosystem Agriculture whether traditional or modern involves intervention and modification of the natural ecological systems. Ever since man has s

STRUCTUR E OF SPERMATOZOAN Structure of sperm is divided into 3 parts -      (1) Head                  (2) Middle piece             (3) Tail 1 .       HEAD

Photosynthetic function Structural organisation of the leaf is suitable to perform the process of photosynthesis. Hence leaf is called as a food factory. The leaf has a l

What is test battery A series of tests (called a test battery) will be given. One widely used battery is Halstead Reitan, which includes measures of verbal and nonverbal intell

Alterations occurring in nuts and oilseeds Some oilseeds have acquired a great significance in the large-scale industrial production of edible oils.  You have already studied t