Which of the following statements is not true with respect to variation?
(a) All variations in a species have equal chance of survival
(b) Change in genetic composition results in variation
(c) Selection of variants by environmental factors forms the basis of evolutionary processes.
(d) Variation is minimum in asexual reproduction
(a) All variations in a species have an equal chance of survival, this statement is incorrect. Some variations are too drastic that the new DNA cannot work with it, such as the death of a newborn cell.
(b) Change in genetic composition results in variation: True
(c) Selection of variants by environmental factors forms the basis of evolutionary processes: True
(d) Variation is minimum in asexual reproduction: True
Therefore, option (a) is correct.