If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Unit 4: Cell communication and cell cycle

600 possible mastery points

About this unit

Prepare to dive deep into the inner workings of cells! In this unit, you'll learn about how cells communicate with one another, how cells divide, and how problems can arise when these processes go wrong.

Level up on the above skills and collect up to 240 Mastery points
"Why am I so sweaty?" is something you will never have to say again! Because now you'll know exactly why.
A typical proliferating human cell will undergo a complete cell cycle in about 24 hours.
Level up on the above skills and collect up to 240 Mastery points
Up next for you:

Unit test

Level up on all the skills in this unit and collect up to 600 Mastery points!
Biology is brought to you with support from the Amgen Foundation
AP® is a registered trademark of the College Board, which has not reviewed this resource.