Cytokinesis: Animal Versus Plant Cells

Lesson Transcript
Instructor: Greg Chin
What's a cell to do when it must divide in two? We'll explore cytokinesis and see how the process can differ in important ways when it comes to plant versus animal cells. Updated: 11/22/2019

Cell Division

If we're talking about cell division, at some point, the cell should actually divide. But so far, all mitosis has done is produce a cell with two nuclei. Cytokinesis is the process in which the cytoplasmic content of the cell is divided into two new daughter cells. While it's easier to consider the events of cytokinesis separately from mitosis, in actuality, there is some overlap between the two. Luckily for us, the mechanisms that govern cytokinesis are far less complicated than those of mitosis.

In cytokinesis, the cytoplasmic content of a cell divides into two new daughter cells

Mitosis was all about ending up with a precise number of chromosomes. On the other hand, division of the rest of the contents of the cell is far less precise. Having an unequal number of chromosomes in the resulting daughter cells would be a bad thing, but having an unequal number of cytoplasmic content, like ribosomes or mitochondria, isn't. The total number of organelles, proteins and other molecules floating in the cytoplasm is so big that even an arbitrary division of the cytoplasmic content in the cell gives each daughter cell enough functionality to survive.

For instance, if a dividing human cell had 1000 mitochondria, a division of 450 in one cell and 550 in another cell still means that both cells can produce enough energy, even though one daughter cell still has ten percent less energy producing capacity than its mother had. So, how do we turn one cell into two cells? It turns out that the strategy used for animals cells is different from what plant cells do, so let's see what type of strategy each cell employs.

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Asexual vs. Sexual Reproduction: Comparison & Characteristics

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:06 Cell Division
  • 1:55 Animal Cells
  • 3:07 Plant Cells
  • 4:50 Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed

Animal Cells

We talked about how animal cells are like water balloons. The cytokinesis strategy employed by animal cells is reminiscent of this fact. As mitosis is ending, cytokinesis begins to divide the cell and its contents into two new daughter cells. This basically looks like you looped a string around the outside of a water balloon and started to constrict it like a drawstring. Obviously, the real-life example doesn't end up so well for us, since we end up with a face full of water. Luckily, what happens for the cell isn't quite as messy.

In animal cells, division involves myosin and a contractile ring made of actin filaments
Animal cell division

During cytokinesis, the role of the string is played by the contractile ring. Now, the contractile ring is composed of actin filaments that are assembled just below the cell membrane. A protein called myosin works with the assembled filaments to constrict the ring until the cell membrane touches in the middle. Once those membranes pinch together, they fuse, and the result is two new cells. Each cell has one nucleus, compliments of mitosis, and each cell has about half of the cytoplasmic content, compliments of cytokinesis.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it now
Create an account to start this course today
Used by over 30 million students worldwide
Create an account