Question

In a wild-type carnivorous plant, protein X is encoded by a haplosufficient gene “X”. The X protein normally homodimerizes. The X-X dimer enzymatically catalyzes a biochemical reaction that is critical for the digestion of insects that it traps. XD represents a dominant negative allele, a mutation, of gene X.
What would be the predicted phenotype of a plant with the genotype X+/XD ? Which one of these pieces of information allows you to reach that conclusion?

	a.	The plant would be mutant and would not digest bugs, because absolutely no X-X dimers will form in the heterozygote.
	b.	The plant would be mutant and incapable of digesting insects, because X is known to be haplosufficient.
	c.	The plant would be wild type and would be quite capable of bug digestion, because XD is a negative allele.
	d.	The plant would be wild type and would produce the enzyme for digestions of insects, as X is haplosufficient.
	e.	The plant would be mutant and would be incapable of digesting insects, as the mutant allele XD is a dominant allele.

Answer 1

Ans- Option b is correct- the plant would be mutant and incapable of digesting insects, because X is known to be haplosufficient.

Explanation- Firstly, the plant is mutant because XD gene is present, that is mutant and secondly, it would be unable to digest insects because the gene X is haplosufficient.