In research on ageing (both cellular ageing and organismal ageing), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following, if found in cells or organisms as they age, would provide evidence that this is related to cell signalling?
A) Growth factor ligands do not bind as efficiently to receptors.
B) Hormone concentrations decrease.
C) cAMP levels change very frequently.
D) Enzymatic activity declines.

Question

Quizplus · Accepted Answer

A decrease in the efficiency of growth factor ligands binding to receptors suggests that there has been a change in cell signaling, as these ligands are responsible for initiating many signal transduction pathways in the cell cycle. Hormone concentrations decreasing would not necessarily indicate a specific change in cell signaling, as hormones have various roles in the body beyond cell signaling. cAMP levels changing frequently would suggest dysregulation of a specific signaling pathway, but this may not be directly related to the cell cycle. Enzymatic activity declining also may not directly indicate a change in cell signaling, as enzymatic activity can be affected by various factors unrelated to signaling pathways.

In Research on Ageing (Both Cellular Ageing and Organismal Ageing)