Why do we break the body into "systems" when discussing it? why don't we just talk about the entire body all at once?

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.

What happens during interphase? (1)the nucleus grows to its full size. (2)the cell grows to its full size. (3)the nucleus divides into two nuclei. (4)the cell divides into two cells.

The diagram below represents a chloroplast found in a typical plant cell. which of the following processes occurs inside this structure? question 8 options: a oxygen is produced b sunlight is trapped c glucose is produced d all of the above.