Question

The image shows antibiotics being administered to destroy bacteria.



image.png



Which best describes what is occurring in the image?


The bacteria develop a mutation that is harmful to their survival.


The bacteria develop a mutation that is beneficial to their survival.


The bacteria choose to change their genetic makeup to provide an advantage.


The bacteria choose to change their genetic makeup to cause harm to the antibiotics.



Part B:

Which BEST supports the choice from Part A?


Bacteria survive being exposed to antibiotics and pass their gene onto offspring, decreasing their chances of survival.


Bacteria survive being exposed to antibiotics and pass their gene onto offspring, increasing their chances of survival.


Bacteria select a gene that is resistant to antibiotics and pass it to their offspring, increasing their chances of survival.


Bacteria select a gene that is harmful to antibiotics and pass it to their offspring, decreasing their chances of survival.

Answer 1

Part A: The bacteria develop a mutation that is beneficial to their survival.

Reason: Antibiotic exposure selects for randomly occurring resistant mutants — bacteria do not "choose" to change their genes.

Part B: Bacteria survive being exposed to antibiotics and pass their gene onto offspring, increasing their chances of survival.

Reason: Resistant individuals survive the antibiotic, reproduce, and increase the frequency of the resistance allele in the population (natural selection).