Answer: It is because it makes it more efficient to study organisms.
Explanation: Biologist classify organisms by considering similarities between them. The organisms which have closely related characteristics are placed in a separate domains by biologists. Domains are further divided into 6 Kingdoms. According to modern classification system, domain is largest unit of biological classification.
Your blood also carries oxygen inhaled by the lungs. Your circulatory system delivers oxygen and nutrients to the other cells of your body then picks up any waste products created by these cells, including carbon dioxide, and delivers these waste products to the kidneys and lungs for disposal
Chromosomes, which are found in the nucleus of a cell, contain genes. A gene is basically a section of DNA, which carries some type of coding for particular protein. The structure in which all genetic information can be found is your DNA (short for D<span>eoxyribonucleic Acid). (I don't know if the first part helped?).</span>