Which of the following cell types can kill cells that present antigens via MHC on their cell surface?

When did HIV-1 group M likely first emerge in humans in central Africa?

Which of the following are components of the virulence-transmission tradeoff hypothesis? Select all that apply.

Which of the following is an appropriate explanation for the large diversity of lymphocyte receptors?

For which of the following receptor proteins do the corresponding genes undergo somatic recombination?

In terms of genome organization, what type of viruses are retroviruses?

Besides the literal definition of the basic reproductive number R0{“version”:”1.1″,”math”:”R0″}, what can R0{“version”:”1.1″,”math”:”R0″}be a measure of?

How does a virus start to infect a host cell?

In which situation could virulence be an adaptive trait?

Which of the following is NOT a region of the heavy chain of B-cell receptors?