Are there photosynthetic organisms that do not contain chlorophyll? If so, what are these photosynthetic organisms?

What must be true for natural selection to heppen

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.

Can a trait be both polygenic and have multiple alleles? explain why or why not.