The role is speeding up chemical reactions
Answer: The correct answer for the fill in the blank is A) Circulatory, immune.
Circulatory system also called cardiovascular system is a vast network of organs and vessels that allow the circulation of blood so as to transport nutrients, oxygen, other gases, and hormones to different parts of the body.
Blood contains different cells like white blood cells, red blood cells, platelets.
White blood cells ( also called leukocytes) work closely with immune system. They provide defense against pathogen ( disease causing organisms) through various ways ( like ingesting foreign material, producing antibodies to clear the antigens). By doing so, they protect us from infection and disease.
Social Dominance - this is the physical dominance of one individual over another
<span>Spirogyra, otherwise known as pond silk, is a type of algae that can be found in bodies of freshwater. The cells are long, unbranched, and cylindrical, being much longer than they are wide. There is no distinction between the basal and distal end, and they connect to each multiple times over to create the "silk" they are seen as; they also can reproduce sexually and asexually. Each cell has one nucleus and a cell wall composed of pectin surrounded by cellulose. Inside each cell is a very distinct spiraling shape of green, being chloroplast strands. It is these shapes for which the cells are named.</span>
