Question

Who discovered sex-linked inheritance?
A. Morgan
B. Bridges
C. Mc clung
D. Wilson and Stevens

Answer 1

When a gene mutation (allele) is found on a sex chromosome rather than a non-sex chromosome (allosome), sex linkage defines the sex-specific patterns of inheritance and presentation (autosome). These are referred to as X-linked recessive, X-linked dominant, and Y-linked in humans.

Complete answer:
The X and Y sex chromosomes are a particularly important area of genetic linkage. These contain not just the genes that define male and female qualities, but also those that determine a variety of additional features. Sex linked genes are those that are carried on both sexes' chromosomes.The sex of the carrier parent and the sex of the infant are closely related in terms of sex-linked trait inheritance probabilities. These alleles can be X-linked or Y-linked, and they can also be dominant or recessive. Since humans have far more X-linked genes than Y-linked genes, there are far more X-linked traits than Y-linked traits.
Thomas Morgan discovered sex linkage in fruit flies in 1910, when he noticed a disproportionate number of white-eyed males. Morgan's experiment involved mating red-eyed female fruit flies with mutant white-eyed males. Individuals of both sexes became exclusively red-eyed as a result. When these individuals were crossed, several white-eyed males resulted, but no white-eyed females.

So the correct answer is option A.

Note:
Morgan came to the conclusion that the eye colour gene must be encoded on the X chromosome, with white eyes representing the recessive allele. If the recessive allele is present in males, it is the only allele present, and white eyes are seen.