Answer: Immune system
Explanation:
Lymphocytes are a class of white blood cells (leukocytes) involved in immune response when activated by the a foreign molecule (an antigen). B lymphocytes develop in the bone marrow of mammals and are responsible for the production of circulating antibodies.
Thus, lymphocytes are associated with the immune system.
I think the answer is chemosynthesis because deep ocean vents don't get sunlight.
Plant relies on the sun and we relie on the plants