Question

Put the following terms in order from least complex to most complex.

-Blood Cell
-Fish
-Circulatory System
-Heart
-Heart Muscle tissue

Answer 1

- Blood Cell
- Heart Muscle Tissue
- Heart
- Circulatory System
- Fish

A cell is the smallest functioning unit of an organism, so it's the least complex of all. Followed by tissue, the organ (heart), the circulatory system and the organism, which is the fish.