Question

Pick up the correct option with regards to given below figure

• A. $a=$ Male Drosophila $\to$ Genotype of red eyed is $x{y}^{+}$
• B. $b=$ Female Drosophila $\to$ Genotype of white eyed is $x^{+}{y}^w$
• C. $a=$ Female Drosophila $\to 5\%$ ova are without sex-chromosome
• D. Both (a) and (b) can grow on simple synthetic medium

Answer 1

The correct option is A $a=$ Male Drosophila $\to$ Genotype of red eyed is $x{y}^{+}$

(A) Male Drosophila $\to$ Genotype of red eyed in $x{y}^{+}$.

A male has different genotype possibilities than a female. Since he has only one X chromosome (paired with a Y) he will received only one copy of any X linked genes. Whatever the allele the male fly inherits for an X linked gene will determine his appearance, therefore males are said to be Hemizygous for x-linked genes.