MINISTRY OF DEFENCE

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  MINISTRY OF DEFENCE. Establishment Of National University In Islamabad Total position. 29 Domicile , All over Pakistan    Qualification  intermediate to bachelor positions . Project Engineer(Civil) account Officer  supervisor assistant office boy     How to apply.   Apply online through the link https://www.fgei-cg.gov.pk/nup-rec.php   Last date to apply  02 April 2023. No TA/DA Fo Interview 
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Chromosomal Theory of Heridity

Chromosomal theory of Heredity


Chromosomes contain genes and transfer the hereditary characters into new gener-

ation. The function of chromosomes was explained by a German scientist Karl Correns
in 1900. He considered the chromosome, as vehicles for the knowledge of hereditary.

Later on a theory was proposed about chromosomes, by an American scientist
Walter Sutton in 1902. This theory is named chromosomal theory of hereditary.

The details of this theory are as follows:

(1) Hereditary material within the nucleus:
In reproduction two cells, sperms and ova participate in fertilization. Both gametes
have equal contribution within the process. The male gamete contains little cytoplasm.
So it indicates that hereditary material is present within the nucleus.

(ii) Segregation of chromosomes:


The chromosomes show the method of segregation (separation) during meiosis.
This segregation is analogous to the Mendel's experiments.

(iii) Haploid and diploid bodies:


In reproduction gametes are haploid and that they contain one copy of chromosomes.
in diploid individual two copies of chromosomes are present. it's consistent with the
Mendel's experiments.


(V) Independent arrangement of chromosomes:


The chromosomes are arranged in independent manner on the metaphase plate,
this arrangement isn't concerned with other chromosomes. it's consistent with the
independent assortment of chromosomes mentioned by Mendel.

Objection:


Ine objection on chromosomal theory of hereditary Is that when there's inde-
pendent assortment of chromosomes in meiosis, the amount of things (genes) is more

than the amount of chromosomes. this is often considered as a fatal objection about
Sutton's theory.

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