Assertion: The presence of a Y chromosome is not required for male development in Drosophila.
Reason: The sex of Drosophila is determined by the X:A ratio, and not by the presence of a Y chromosome.
Assertion and reason are both true, and reason is an accurate account of assertion.
Both assertion and reason are accurate, but reason does not adequately explain assertion.
The assertion is correct, but the reasoning is incorrect.
Both the assertion and reason are incorrect.
In Drosophila, the sex of an individual is determined by the X:A ratio, where males have one X chromosome and two sets of autosomes, while females have two X chromosomes and two sets of autosomes. Unlike in many other organisms, the presence of a Y chromosome is not required for male development in Drosophila. Therefore, Drosophila males do not have a Y chromosome. Instead, the X:A ratio determines the sexual fate of the fly. This mechanism is known as X-linked sex determination, and it ensures that males and females are produced in a precise ratio. Mutations in genes involved in the X-linked sex determination pathway can lead to disorders of sex development in flies, just as they can in humans.
Option 1 is the correct answer.