NEET2003ZoologyPrinciples of Inheritance and VariationActual
In Drosophila, the sex is determined by,
Options
- Athe ratio of number of X-chromosome to the sets of autosomes
- BX and Y chromosomes
- Cthe ratio of pairs of X -chromosomes to the pairs of autosomes
- Dwhether the egg is fertilized or develops parthenogenetically
Correct answer
A. the ratio of number of X-chromosome to the sets of autosomes
Step-by-step solution
In Drosophila, sex is primarily determined by the X : A ratio, or the ratio of the number of X chromosomes to the number of sets of autosomes not because of the presence of a Y chromosome as in human sex determination. Although the Y chromosome is entirely heterochromatic, it contains at least 16 genes, many of which are thought to have male-related functions. Related Theory In butterflies, sex is determined by chromosome differences. But unlike in humans with the familiar X and Y , in butterflies, it is the femate