Ответ:

1. Chemical level – is the simplest level.

2. Cellular level – the cells.

3. Tissue level – epithelium, connective, muscle, and nervous tissue.

4. Organ level - brain, stomach, liver etc.

5. Organ system level – skeletal, nervous, muscular, endocrine, respiratory, lymphatic, digestive, urinary, and reproductive systems.

6. Organismal level – the human.

Объяснение: