Question

You engineer yeast cells that express the M cyclin during S phase by replacing the promoter sequence of the M cyclin gene with that of S cyclin. Keeping in mind that yeast cells have one common Cdk that binds to all cyclins, which of the following outcomes is least likely during this experiment? (a) There will be both M cyclin-Cdk and S cyclin-Cdk complexes in the cell during S phase.(b) Some substrates that are normally phosphorylated in M phase will now be phosphorylated in S phase.(c) G1 cyclins will be expressed during S phase.(d) S-Cdk targets will be phosphorylated during S phase.

Answer 1

Answer:

(c) G1 cyclins will be expressed during the S phase

Explanation:

In those cases in which G cyclins are constitutively expressed, the G1 phase will be shortened