In a long term experiment of a population of Drosophila melnogaster, the frequency of two alleles 'a' and 'b' of a multi-allelic locus X over time has been shown in the following graph.

6 students were asked to evaluate the observed pattern and their inferences are given below.
Statement 1: Enviorment is not uniformly slective.
Statement 2: Population may be under artificial selection.
Statement 3: Genetic variability is progressively reduced.
Statement 4: Genetic varuability is progressively increased.
Statement 5: Mechanism such as genetic drift is operating from time to time.
Statement 6: Selection is favouring a particualr genotype through directional selection.
The appropriate conclusions were draws by

Options

A. Students 2,6 and 6
B. Students 1,3 and 5
C. Students 2,3 and 6
D. Studnets 1,3 and 6.

Answer

C

Explanation

Accroding to the given graph, the environment must be uniformly selective since. It is leading to increase and decrease in frequency of alleles 'a' and b' respectively. Therefore, genetic variability is reducing at a very fast rate, it could be a resutl of artificial selection. Genetic drift does not seem to operating time to time to time because drift is casued by a chance event rather a directed selective process, Here, selection is favouring a particualr genotype, since frequency of allele 'a' is increasing through the generations.