Reading- this is the story the other part is on my page go to my questions

The energy needs of a human population are not affected by

The following image is of a diatom. it lives in water and gets food from photosynthesis. it is encased in a hard shell made of something similar to glass or sand . a diatom is a(n) because it has a) multi-celled organism; specialized parts. b) vertebrate; a skeleton. c) insect; an exoskeleton. d) single-called organism; only one cell.

In what part of the body does the most muscle activity happen?