Question

What led to the initial development of the concept of the genetic basis of sex determination?

• A. Chromosomal observations in humans
• B. Cytological observations in birds
• C. Cytological observations in insects
• D. Chromosomal observations in birds

Answer 1

The correct option is C Cytological observations in insects

Some of the experiments carried out in insects had given the clue about the genetic basis of sex determination. The cytological observations made in several insects led to the development of the concept of the genetic basis of sex determination.
For example, during a cytological study conducted by Henking (1891) on the chromosomes of firebugs, it was observed that only 50% of the sperms had a specific structure after spermatogenesis. This was later given the name X - chromosome.