The main function of the circulatory system is to move materials throughout the body, blood for cellular respiration, sugars for energy, leukocytes for immune support, and other nutrients necessary for proper homeostasis.
Humoral immunity<span> or humoural </span>immunity<span> is the aspect of </span>immunity<span> that is </span>mediated<span>by macromolecules found in extracellular fluids such as secreted </span>antibodies<span>, complement proteins, and certain antimicrobial peptides. Humoral </span>immunity<span> is so named because it involves substances found in the humors, or body fluids.</span>
Answer - Well to put it in short terms.
Cells such as water cells or aquatic microorganisms need and required to have a large surface area increased. Because this helps them stay afloat without spending much amount of energy to float.
A haploid cell is one that contains one set of complete chromosomes.