4) Which of the following statements about B-cells is incorrect?
A) B-cells differentiate into plasma cells when activated
B) B-cells require an antigen to be presented to them by other cells
C) B-cells have membrane bound antibodies called B-cell receptors
D) B-cells participate in humoral immunity

B

Explanation:

It's the T-cells that need the antigens to be presented to them for activation, via antigen presenting cells (APCs), like macrophages, dendritic cells and even B- cells themselves.

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation:

very