Question

Appearance of antibiotic-resistant bacteria is an example of:

• A. pre-existing variation in the population
• B. transduction
• C. divergent evolution
• D. adaptive radiation

Answer 1

The correct option is A pre-existing variation in the population

Adaptive radiation:

The process by which new species are formed by adapting to its environment from a common ancestor is called adaptive radiation. Example: The evolution of the beak structures in Darwin's Finches.

Transduction:

Transduction is the process of transfer of genetic material through a virus from one bacterium to another.

Pre-existing variation:

Sudden genetic variations due to mutations may occur in bacteria during reproduction. Some of these pre-existing variations may confer certain advantages (example- antibiotic resistance) to certain bacteria. In a bacterial population if there are few bacteria with a resistance to a certain antibiotic, upon exposure to this antibiotic, the one with the pre-existing variation will survive and other bacteria will not survive.

Divergent evolution:

Homologous organs have the same basic plan but perform different functions due to divergent evolution. The organisms have a common ancestor.

Final answer

c. Pre-existing variation in the population