Question

The arrow diagram below depicts the levels of organization.

     Atoms → Molecules → Cells → ? → Organs → Organ Systems → Organism

Which level of organization is missing from the arrow diagram?

A.
tissues

B.
blood

C.
bones

D.
muscles

Answer 1

The missing level of organization in the arrow diagram is:

**A. tissues**

The sequence is: Atoms → Molecules → Cells → Tissues → Organs → Organ Systems → Organism.