Mucous membranes, non-intact skin, the gi, gu or respiratory tract are which link in the chain of infection?

Ecosystems involve living organisms interacting with non-living things in a productive way; how is photosynthesis an example of this? answer, i will give brainiest to first person to get it right.

Why is the theory of evolution important? it disproves all other theories about how life began. it provides a topic for debate. it is a unifying concept in biology. it explains how life began. i know for sure, it is not "it is a unifying concept in biology."

Explain how the number of similarities between the embryos from early stage to late stage is used as evidence of a common ancestry