Assertion (A): Darwin's theory of natural selection suggests that all…

The correct answer is Option (4) → Assertion (A) is wrong but Reason (R) is correct.

Natural selection rests on the fact that the members of a population are not all alike. Some have traits that help them survive and reproduce better in their environment, so their chances are not equal.

Assertion (A): Darwin's theory of natural selection suggests that all individuals in a population have an equal chance of survival. — False. Darwin said the opposite. Individuals that are better fit survive more and leave more progeny, and nature selects them. If all had equal chances, there would be nothing to select.

Reason (R): Variations among individuals lead to differential survival and reproduction, favouring those with advantageous traits. — True. This is the core of Darwin’s idea. Variations give some individuals an advantage, so they outbreed others, and their traits become common over generations.

The Assertion is false and the Reason is true.

NCERT Extract:
Evolution of Life Forms – A Theory – “… Those characteristics which enable some to survive better in natural conditions (climate, food, physical factors, etc.) would outbreed others that are less-endowed to survive under such natural conditions. Another word used is fitness of the individual or population. The fitness, according to Darwin, refers ultimately and only to reproductive fitness. Hence, those who are better fit in an environment, leave more progeny than others. These, therefore, will survive more and hence are selected by nature. He called it natural selection and implied it as a mechanism of evolution.”