What are the building blocks of nucleic acids

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 breakdown of food is accomplished by enzymes. a. physical b. chemical c. mechanical d. none of the above

Where substance is produced during cellular respiration