Natural Selection Unit Test Unit 5 Lesson 12

Question

The dots represent a bacterial infection. Sal was very sick with this bacterial infection. The infection was treated with antibiotics. Sal seemed to get well, but in a few weeks, she was sick again. How can this be explained using natural selection?

(1 point)
Responses

The antibiotics were ineffective to this strain of bacteria.
The antibiotics were ineffective to this strain of bacteria.

The stronger, more resistant bacteria survived the antibiotics and reproduced.
The stronger, more resistant bacteria survived the antibiotics and reproduced.

The antibiotics did not kill the bacteria; it only forced them to be dormant.
The antibiotics did not kill the bacteria; it only forced them to be dormant.

Antibiotics will only kill a portion of the bacteria, no matter how much medicine Sal takes.

Answer 1

The stronger, more resistant bacteria survived the antibiotics and reproduced. This led to a new population of bacteria that were resistant to the antibiotics, causing Sal to get sick again. This is an example of natural selection at work, as the bacteria that were able to survive and reproduce in the presence of the antibiotics were the ones that passed on their resistant genes to the next generation.