Organisms change over time. Some of these changes make no difference to the success or failure of the organisms that inherit them; other changes do. Take a group of antelopes in which one individual has longer legs than its siblings. Those longer legs make the individual better at escaping from predators, hence giving it an advantage in the survival stakes. Its descendants inherit this feature and are better able to survive as a consequence. Those longer legs have thus become an 'adaptation'. Their evolution means that this particular lineage of antelopes has adapted to its conditions, thanks to its development of this feature.
Over the generations, the individual components of the genetic code within a species change, or mutate. So far as we know, mutations may provide no evolutionary advantage at all. They may be disadvantageous, in which case they are weeded out via natural selection; or they may be advantageous, in which case they persist through the generations.
Choose the most appropriate meaning of the given word:
MUTATION
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → undergo a change in the genetic code
Mutation means a change in the genetic code (the genes) of a living thing, which may then be passed on to its descendants. The passage uses it in this sense: the components of the genetic code within a species "change, or mutate".
Example: A single mutation in the virus made it spread faster.
Why the Other Options are Incorrect?
Option 2: transform into another organism — Incorrect. Wrong meaning: a mutation changes a gene; the organism remains the same kind of organism.
Option 3: a rupture in the organism's growth — Incorrect. Wrong meaning: a rupture is a break or burst. A mutation is a change in the genetic code, not a break in growth.
Option 4: rapid change in the bone structure of the organism — Incorrect. Too narrow: a mutation may affect any feature, and it is a change in the genes, not specially a quick change in the bones.