Final answer:
B cells proliferate in Burkitt lymphoma, a type of cancer that affects the lymphatic system, leading to the formation of tumors composed of malignant B lymphocytes.
Step-by-step explanation:
The type of cells that proliferate in Burkitt lymphoma are B cells. Burkitt lymphoma is a form of cancer where masses of malignant B lymphocytes collect in the lymph nodes, spleen, liver, and other tissues. These B lymphocytes, a type of white blood cell, are a critical part of the adaptive immune system and are typically responsible for the production of antibodies once they become activated and differentiate into plasma cells.
B cells initially develop from bone marrow and continue to mature there. Upon activation, these B cells can turn into large numbers of antibody-producing cells known as plasma cells. The uncontrolled proliferation of these B cells in Burkitt lymphoma leads to the formation of characteristic tumors that can be visually identified due to their irregularly shaped abnormal lymphocytes.