#Question id: 1509
#Unit 4. Cell Communication and Cell Signaling
Cells that are infected, damaged, or have reached the end of their functional life span often undergo "programmed cell death." This controlled cell suicide is called apoptosis. Select the appropriate description of this event on a cell's life cycle.
#Question id: 27004
#Unit 10. Ecological Principles
#Question id: 4016
#Unit 3. Fundamental Processes
Activators that stimulate this kind of promoter work by triggering a conformational change in either RNA polymerase or DNA; that is, they interact with the stable closed complex and induce a conformational change that causes transition to the open complex. This mechanism is an example of
#Question id: 1156
#Unit 4. Cell Communication and Cell Signaling
Which of the following mechanisms cannot terminate an intracellular signaling pathway once the concentration of an external signal decreases?
#Question id: 3649
#Unit 3. Fundamental Processes
In eukaryotes, clusters (tandem arrays) of about 20–50 replicons initiate simultaneously at defined times throughout: