In the human body, oxygen is absrobed by the lungs and nutrients are absorbed by the small intestine. in a single-celled organism, what this absorption directly involves

cell membrane

Explanation:

Single cell organisms like the bacteria depend mostly on diffusion for gaseous exchange. They take in food that does not require complex digestion processes. The cell membrane is selectively permeable and allows absorption of nutrients like glucose that have molecules of small size.

the answer is a) a shiprock was formed by igneous process