Relationship between periosteum and compact bone

Cells tend to have a relatively small and uniform size. why aren’t cells larger?

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.

Talking listening and reacting non verbally are all part of communicating