The statement that is not true with respect to variation is (a) “All variations in a species have equal chance of survival” because different variations can confer different advantages or disadvantages in different environments, leading to unequal survival probabilities.
Explanation:
(b) Change in genetic composition results in variation:
This is true, as changes in DNA sequence lead to new traits and variations within a population.
(c) Selection of variants by environmental factors forms the basis of evolutionary processes:
This is also true, as natural selection favors variations that are better suited to the environment, leading to evolutionary change over time.
(d) Variation is minimum in asexual reproduction:
This is true because in asexual reproduction, offspring are genetically identical to the parent, resulting in minimal genetic variation within the population. However, some sources mention that even in asexual reproduction, there can be slight variations due to environmental factors.