Biology / Unit 4 Bio 0875 short lesson, about 20 seconds
External Regulation of the Cell Cycle
Captions available
The idea
External regulation of the cell cycle triggers or blocks division through signals from outside the cell, including growth factors, nearby cell death, and physical crowding.
In practice
A shortage of human growth hormone can inhibit division broadly enough to cause dwarfism, while an excess causes gigantism.
Where people slip
A dividing cell always receives its initiating signal from outside — division is never a spontaneous, internal event.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Something wrong in this lesson? Flag it · Sources for Biology