Indicate true (T) and false (F) statements below regarding cellular control of growth and division. Your answer would be a four-letter string composed of letters T and F only, e.g. TFTF.
( ) Replicative cell senescence usually arises due to the accumulation of mutations in genes encoding S- and M-cyclins.
( ) Replicative cell senescence is caused by the induction of apoptosis by p53.
( ) Excessive mitogenic stimulation can result in Mdm2 activation and the induction of apoptosis or cell-cycle arrest.
( ) The Mdm2 inhibitor Arf induces cell-cycle progression.

Question

Indicate true (T) and false (F) statements below regarding cellular control of growth and division. Your answer would be a four-letter string composed of letters T and F only, e.g. TFTF.
( )	Replicative cell senescence usually arises due to the accumulation of mutations in genes encoding S- and M-cyclins.
( )	Replicative cell senescence is caused by the induction of apoptosis by p53.
( )	Excessive mitogenic stimulation can result in Mdm2 activation and the induction of apoptosis or cell-cycle arrest.
( )	The Mdm2 inhibitor Arf induces cell-cycle progression.

Quizplus · Accepted Answer

Replicative cell senescence is a result of the shortening of telomeres in somatic cells that lack telomerase activity. Eventually, the unprotected chromosome ends trigger cell-cycle arrest or apoptosis through p53 activation. Excessive stimulation by mitogens can also activate p53, since the cell-cycle inhibitor Arf is activated under excessive Myc or Ras activity and inhibits the p53 inhibitor Mdm2.

Indicate True (T) and False (F) Statements Below Regarding Cellular