How can you tell which side of the heart is the ventral surface? not from the internet please!

An easy way to calculate the amount of energy available at each level is to what?

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.

Explain why the plants cortex would serve as the best food source for animals