The Model Virus Bacteriophage λ (Lambda) Has Been Used Extensively

Multiple Choice

The model virus bacteriophage λ (lambda) has been used extensively to study the lysogenic mechanism.The virus genome includes genes that encode the regulator proteins cI and Cro, which compete for specific promotors on the viral DNA-including their own promotors.Cro and cI have opposite effects on each promotor: cI represses the expression of genes involved in the lytic cycle and promotes expression of genes involved in lysogeny, whereas Cro does the opposite.Suppose a mutation in Cro increases its expression.This mutation would make entering lysogeny _______ likely.A mutation that increases the expression of cI would have _______ effect on the likelihood of the virus entering lysogeny.

A) more; a similar
B) more; no
C) more; the opposite
D) less; a similar
E) less; the opposite