a cell is the smallest structural and functional unit of an organism
During respiration, members of the animal kingdom use oxygen and then release carbon dioxide as a waste gas.
Members of the animal kingdom have a respiratory system that is composed of muscles, and airways that functions together to transport air into lungs, and the oxygen is used by cells. Carbon dioxide is also transported away from the cells as a waste gas. Respiration relies on other systems, such as the circulatory system, to transport oxygen and carbon dioxide to and from cells.
C. The associates proteins are histones
Diffusion is the passive transport from a high concentration to a low without using energy. homeostasis results from balance.