It is intended to increase immunity against that antigen back to protective levels, after memory against that antigen has declined through time.
Answer: Spleen
Explanation: The spleen is an organ in the abdomen, under the ribs on the left side of the body. It stores lymphocytes, filters the blood and destroys old blood cells. As blood passes through the spleen, lymphocytes attack any bacteria or virus or other types of harmful substances that can cause infection or illness.
Instructions for making proteins are stored in DNA
Https://www.amnh.org/exhibitions/permanent/planet-earth/why-is-the-earth-habitable/life-that-lives-off-the-earth-s-energy/life-at-the-hydrothermal-vents
Hope this helps!
Standard deviation, really hope this helps you out :)
