Answer:
d. Humans and other animal hosts lack peptidoglycan cell walls.
Explanation:
Humans and other animals lack cell walls. Bacterial cells have peptidoglycan cell walls around them. The absence of cell walls in the cells of human and other animal host ensures that these cells are not affected by the drugs that target the peptidoglycan cell walls to kill or slow down the growth of the bacterial pathogen.
This makes the drugs specifically target the bacterial cells only while not affecting the host cells. If a drug would target a component present in cells of both the pathogens and hosts, the host cells would be most likely to be harmed by the drugs.
D should be the answer as they are no longer able to perform sexual reproduction without the other fish. Therefore, they would die off because they have lost the partner needed to reproduce.
Hope this helps!
<em><u>Answer</u></em>
<em><u>about 3.9 billion years ago</u></em>
<em><u>about 3.9 billion years agoThe most recent common ancestor of all currently living organisms is the last universal ancestor, which lived about 3.9 billion years ago.</u></em>