Question

Genic balance theory for sex determination in Drosophila was proposed by

• A. Pro. R. P. Roy
• B. H. E. Warmke
• C. C. B. Bridges
• D. McClung

Answer 1

Answer: (C)

C. B. Bridges

Genic Balance Theory was proposed by C.B. Bridges in 1922 for sex determination in Drosophila. It states that ratio of number of X-chromosome to that of complete set of autosome determine the sex of Drosophila. According to this theory of sex determination, if the ratio of X chromosome to total number of sets of autosomes (X/A) is >1, the organism will be super female. If the ratio of X chromosome to total number of sets of autosomes (X/A) falls between 1 and 0.50, the genotype will show intersex phenotype. The X/A value is 1.0 for normal female and 0.5 for normal male. Option C is correct answer.