Which one of the following statements about variations is not true ?
Variation is minimum in asexual reproduction.
All variations in a species have equal chances of survival.
Changes in genetic constitution result in variation.
Variants can be selected by environmental factors.
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC CDS-2 – 2021
B) All variations in a species have equal chances of survival: This statement is false. Survival is not random with respect to variations. Variations confer different traits on individuals. Depending on the environmental conditions, some traits (and thus the variations that cause them) may be advantageous, increasing an individual’s chances of survival and reproduction. Other variations may be disadvantageous, decreasing the chances of survival. This differential survival and reproduction based on variations is the basis of natural selection.
C) Changes in genetic constitution result in variation: Variations are heritable differences between individuals. These differences arise from changes in the genetic material (DNA), such as mutations (changes in nucleotide sequence) or rearrangements of chromosomes, as well as the combination of genes inherited from parents in sexually reproducing organisms. So, this statement is true.
D) Variants can be selected by environmental factors: This is a fundamental principle of evolution by natural selection. Environmental conditions act as selective pressures, favouring individuals with certain variations that make them better adapted to that environment. These individuals are more likely to survive and pass on their advantageous variations to their offspring. This statement is true.
The statement that is NOT true is B.
– Sexual reproduction generates more variation than asexual reproduction.
– Natural selection acts on variations; survival is not equally likely for all variations.
– Environmental factors drive the selection of variants.