A significant body of research indicates for exam stress; large scale disasters; loss of a spouse; response to viral challenge including herpes simplex, Epstein Barr, HIV, and cold virus; and long-term caregiving by loved ones of persons with dementia. immune system growth immune system suppression increased growth of phagocytes immune dysregulation

immune system suppression

Explanation:

Research indicated suppression of the immune system can have many causes like stress during exam releases corticosteroid which is a stress hormone that reduce the function of the immune cell thereby suppress the immune system.

Emotional stress like loss of a spouse or loved ones suppresses the immune system of a person and makes a person vulnerable to disease. Viral challenges especially those that attack the immune system suppress our immune system.  

Research suggests that Dementia caregivers are at increased risk of lower immunity, cardiovascular disease and lower immune response towards vaccine.

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.