Question

A variety of microorganisms live as symbionts in the human digestive tract. What determines whether their relationship with the human is parasitic or mutualistic?

a their size compared to human cells
b their reproductive rate compared to the replication rate of human cells
c. whether or not they gain energy from food that the human eats
d whether their actions harm or benefit the human host

Answer 1

Answer: D, whether their actions harm or benefit their human host.

Explanation: The nature of the relationship between the host and microorganism can be categorized based on whether the actions of the microorganism harm or benefit the host.