Answer
385.5k+ views
Hint: When the gene resides on the same chromosome pair is termed as linkage and the linkage between the two dominant alleles and two recessive alleles is termed as coupling. Repulsion indicates that dominant alleles are linked with recessive alleles.
Complete answer:
Several dihybrid crosses were carried out in drosophila by Morgan to study the sex-linked genes. These crosses were quite similar to the hybrid crosses carried out by Mendel in peas. For example, Morgan hybridized yellow bodied white-eyed females to brown bodied Red-eyed males and intercrossed their F1 progeny. He observed that the two genes did not segregate independently of each other and the F2 ratio deviated very significantly from the\[9:3:3:1\] ratio. Morgan and his group were aware that the genes were located on the X chromosome and noticed quickly that when the two genes in a dihybrid cross were situated on the same chromosome, the proportion of parental gene combinations were much more advanced than the non-parental kind. Morgan attributed this is due to the physical association or linkage of the two genes the coined the term linkage to describe this physical association of genes on a chromosome and the term recombination to explain the generation of non-parental gene combinations. He and his group found that two completely linked genes showed a dihybrid ratio of\[1:1:1:1\].
Thus option C is the correct answer.
Note:
Morgan and his group also found that even when genes are grouped on the same chromosome, some genes were very tightly linked while others were loosely linked. For example, he found that the white and yellow very very tightly linked and showed only \[1.3\]\[\% \] recombination while the white and miniature wing showed \[37.5\]\[\% \] recombination.
Complete answer:
Several dihybrid crosses were carried out in drosophila by Morgan to study the sex-linked genes. These crosses were quite similar to the hybrid crosses carried out by Mendel in peas. For example, Morgan hybridized yellow bodied white-eyed females to brown bodied Red-eyed males and intercrossed their F1 progeny. He observed that the two genes did not segregate independently of each other and the F2 ratio deviated very significantly from the\[9:3:3:1\] ratio. Morgan and his group were aware that the genes were located on the X chromosome and noticed quickly that when the two genes in a dihybrid cross were situated on the same chromosome, the proportion of parental gene combinations were much more advanced than the non-parental kind. Morgan attributed this is due to the physical association or linkage of the two genes the coined the term linkage to describe this physical association of genes on a chromosome and the term recombination to explain the generation of non-parental gene combinations. He and his group found that two completely linked genes showed a dihybrid ratio of\[1:1:1:1\].
Thus option C is the correct answer.
Note:
Morgan and his group also found that even when genes are grouped on the same chromosome, some genes were very tightly linked while others were loosely linked. For example, he found that the white and yellow very very tightly linked and showed only \[1.3\]\[\% \] recombination while the white and miniature wing showed \[37.5\]\[\% \] recombination.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Why Are Noble Gases NonReactive class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let X and Y be the sets of all positive divisors of class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x and y be 2 real numbers which satisfy the equations class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x 4log 2sqrt 9k 1 + 7 and y dfrac132log 2sqrt5 class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x22ax+b20 and x22bx+a20 be two equations Then the class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
At which age domestication of animals started A Neolithic class 11 social science CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Which are the Top 10 Largest Countries of the World?
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Give 10 examples for herbs , shrubs , climbers , creepers
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference Between Plant Cell and Animal Cell
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Write a letter to the principal requesting him to grant class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Change the following sentences into negative and interrogative class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Fill in the blanks A 1 lakh ten thousand B 1 million class 9 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)