Label the internal structure of the earth

An organ system consists of a group of organs that performs specific functions necessary for the survival of an organism. humans have eleven different organ systems: integumentary, skeletal, muscular, nervous, endocrine, circulatory, lymphatic, respiratory, digestive, urinary, and reproductive. discuss the function of neurons, the brain and the spinal cord within the human nervous system while explaining the interrelationship of each organ.

The kind of fertilization found in the majority of aquatic animals is (internal or external) fertilization.

This is the interaction of two organisms where one is and the other is neither nor harmed.