Question

This is the original question - Ques - A researcher exposed Drosophila larvae to 37°C during their growth. One of the adult flies that emerged had a crossveinless phenotype. When this crossveinless fly was crossed to a known crossveinless mutant fly all the progeny had normal phenotype. The options had both condition mutant and phenocopy. What is the difference between condition mutant and phenocopy? Any specific points I can use differentiate between them in such a question?

Answer 1

A condition mutant refers to a genetic mutation that only manifests its effects under certain conditions, while a phenocopy refers to a non-genetic change in phenotype that mimics a specific genetic mutation. In the case of Drosophila larvae exposed to 37°C, the crossveinless phenotype only appeared when the larvae were grown under these specific conditions, indicating a condition mutant. When the crossveinless fly was crossed with a known crossveinless mutant fly, all the progeny had a normal phenotype, indicating a phenocopy.

Step-by-step explanation:

The difference between a condition mutant and a phenocopy can be understood by looking at the underlying causes and inheritance patterns. A condition mutant refers to a genetic mutation that only manifests its effects under certain conditions, such as changes in temperature or other environmental factors. In the case of the Drosophila larvae exposed to 37°C, the crossveinless phenotype only appeared when the larvae were grown under these specific conditions. On the other hand, a phenocopy refers to a non-genetic change in phenotype that mimics a specific genetic mutation. In this case, when the crossveinless fly was crossed with a known crossveinless mutant fly, all the progeny had a normal phenotype, indicating that the crossveinless phenotype was not inherited. Therefore, the difference between a condition mutant and a phenocopy lies in the underlying causes and inheritance patterns of the observed phenotype.