Mitotic CDK complexes are maintained in an inactive state through inhibitory phosphorylation of the CDK subunit. Two highly conserved tyrosine and threonine residues in mammalian CDKs are subject to regulated phosphorylation.

Gene	Mutant phenotypes
A. Wee1	i. the cell does not divide but continues to grow
B. CAK kinase	ii. mitotic cyclins are inactivated
C. cdc25 phosphatase	iii. premature entry into mitosis

The following table enlists genes and phenotypes observed on mutation of these genes but not correctly matched. Which one of the following combinations is correctly matched ?

#Question id: 1403

#Unit 4. Cell Communication and Cell Signaling

Tumor-suppressor genes encode proteins with which of the following functions?

a. growth-promoting               b. growth-arresting                  c. pro-apoptotic

d. anti-apoptotic                      e. DNA repair

#Question id: 1404

#Unit 4. Cell Communication and Cell Signaling

Which of the following are transcription factors?

#Question id: 1405

#Unit 4. Cell Communication and Cell Signaling

A gain-of-function mutation in which of the following would have the same effect as a gain-of-function mutation in Ras?

#Question id: 1406

#Unit 4. Cell Communication and Cell Signaling

Which of the following is a consequence of p53 stabilization?

a. stabilization of Cdc25A      b. activation of ATM                c. blocked apoptosis

d. transcription of p21                        e. DNA repair

#Question id: 1407

#Unit 4. Cell Communication and Cell Signaling

Which of the following is pro-apoptotic?

a. Bax              b. Bcl-2                       c. p53              d. protein kinase B      e. PTEN

#Question id: 1408

#Unit 4. Cell Communication and Cell Signaling

Human papilloma virus encodes proteins that inhibit the function of

a. Bcl-2.           b. Myc.                        c. p53.             d. PDGF receptor.      e. Rb.