People and animals breathe in oxygen from the air and exhale carbon dioxide.
what happens to the carbon dioxide in the air?
a. some animals breathe in carbon dioxide and exhale oxygen.
b. the carbon dioxide floats into the atmosphere and forms clouds.
c. plants use carbon dioxide to make sugars and oxygen.

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.

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this

The frequency of alleles in a population that is in hardy weinberg equilibrium? a . changes in each successive generation b. is less important than the frequency genotypes c. shows evidence of the process of natural selection d. remains the same over several generations