How is sickle cell anemia an example of a pleiotropy? sickle cell anemia is caused by a pair of genes present on different loci of the same chromosome. sickle cell anemia shows a continuous variation in the population. sickle cell alleles affect various organ systems, such as the circulatory and respiratory systems. nextreset

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.

Read each description below and determine to which stage of sleep each pertains. then click and drag each box into the appropriate category below.

What is an example of a scientific question that galileo could not have answered with out this new tool?