Question

All helper T cells are CD4-positive. Consequently, in a normal lymphocyte population, it is reasonable to expect all CD4-positive cells to also be positive for which of the following CD markers?

a) CD8
b) CD19
c) CD14
d) CD3

Answer 1

CD3 is the CD marker that is also present on all CD4-positive cells.

Step-by-step explanation:

Helper T cells are CD4-positive, and all CD4-positive cells are also positive for CD3. CD3 is a CD marker that is found on all T cells, including both CD4 and CD8 T cells. Therefore, the correct answer is d) CD3. CD8 is a marker found on cytotoxic T cells, CD19 is a marker found on B cells, and CD14 is a marker found on monocytes and macrophages.