Question

Which of the following statements is not true with respect to variation?

• A. All variations in a species have an 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

Answer 1

The correct option is A

All variations in a species have an equal chance of survival

The correct option is A.

Explanation of the correct option:

1. The difference between two individuals of a species is termed variation.
2. The genetic variation takes place because of recombination and mutation at the time of meiosis.
3. Some examples of variation are different skin color, height, eyes, etc.
4. All variations in a species do not possess equivalent chances of survival.
5. Some of the variations may be so harmful that the new copy of DNA produced fail to work with the cellular apparatus it inherits.
6. Variations can be harmful or beneficial based on the ecological niche of the organism.

Explanation of the incorrect options:

Option B:

1. Any difference between the cells, group of organisms, or individual organisms resulting either due to the effect of environmental factors on the expression of the genetic potentials or from genetic differences is variation.
2. Thus, variation is a result of the modification in genetic composition.

Option C:

1. A variation appropriate for the specific niche is chosen by nature in the process of evolution.
2. Variations are essential for the survival of the species.
3. The advantageous variations are chosen by the environmental factors, which further results in speciation and evolution.

Option D:

1. Variation generally takes place due to sexual reproduction, as during sexual reproduction, the gametes from distinct parents combine and give rise to a diploid zygote, which further develops into a genetically distinct offspring.
2. On the other hand, variation is negligible in asexual reproduction as genetically identical offspring are produced, however, it can take place in specific cases like due to mutations.

Final answer: All the variations in a species have an equal chance of survival is not true with respect to variation.