What two structures generate the cells responsible for immune responses?

•B lymphocytes and T lymphocytes
•thymus and lymphocytes
•bone marrow and lymphocytes
•bone marrow and thymus

Depending on the organism the number of in a cell may change

(6.02 mc)what affect do marine protected areas have on environmental quality? they increase environmental quality by preventing resource overuse. they increase environmental quality by adding new species. they decrease environmental quality by removing all human activity. they decrease environmental quality by adding recycling facilities.

An uncomfortable feeling in the ears when descending in an airplane is caused by changes in air pressure on the: a. inner ear b. middle ear c. eardrum d. hammer/anvil