Answer:
Cell types I and III are animal and fungal cells, which are most closely related since they are eukaryotic cells that are heterotrophic.
Explanation: ¯\_(ツ)_/¯
The correct answer is (b) <span>They can be directly observed.</span>
Endocrine system regulation slowly happens but produces long-lasting effects, whereas nervous system regulation quickly takes place with short-term effects.
Endocrine system can regulate many things in the body that control the metabolism. The effect shouldn't be instant, but it should be good for long term effect. Nervous system need a much faster reaction because it responsible for "fight or flight" reaction. A slow nervous system will cause the organism caught by predator easier.
Genetic variation is advantageous because it enables some individuals and, therefore, a population, to survive despite a changing environment.