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प्रश्न
Write a note on sex linkage.
उत्तर
- Complete sex linkage:
a. It is exhibited by genes located on non-homologous regions of X and Y chromosomes.
b. They inherit together because crossing over does not occur in nonhomologous regions.
c. Examples of X-linked traits are haemophilia, red-green colour blindness, myopia (near sightedness) and for Y-linked are hypertrichosis, etc. - Incomplete sex linkage:
a. It is exhibited by genes located on homologous regions of X and Y chromosomes.
b. They do not inherit together because crossing over occurs in homologous regions.
c. Examples of X-Y linked traits are total colour blindness, nephritis, retinitis pigmentosa, etc.
संबंधित प्रश्न
Name the ‘two’ types of maps generated by H.G.P.
How did Sturtevant explain gene mapping while working with Morgan?
How many linkage groups are present in Drosophila melanogaster?
Analyse the following statements with respect to complete sex linkage and select the correct option.
- It is exhibited by genes located on non-homologous regions of X and Y chromosomes
- Y-linked trait is hypertrichosis.
- X-linked traits are haemophilia, red-green colour blindness, myopia (near sightedness).
Which of the following statement/s are INCORRECT with respect to crossing over?
i. Crossing over produces recombinations of genes by interchanging and exchanging corresponding segments between nonsister chromatids of homologous chromosomes.
ii. Crossing over occurs during zygotene of prophase I of meiosis.
The number of linkage groups of a particular species corresponds to its ______ number of chromosomes.
Two crosses between the same pair of genotypes or phenotypes in which the sources of the gametes are reversed in one cross, is known as ______.
Which of the following is correct for the condition when plant YyRr is back crossed with the double recessive parent?
The following are results of crossing a female fly (AaBb) with a male fly (aabb).
- AaBb 1005
- aabb 1000
- Aabb 200
- aaBb 210
Which two genotypes are the recombinant offspring?
Linkage groups can be separated during ______ in meiosis.
