What Is Interphase? - Definition & Stages

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

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

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:04 What is Interphase?
  • 0:37 What Happens During G1?
  • 2:09 What Happens During S?
  • 3:01 What Happens During G2?
  • 3:52 Lesson Summary
Autoplay
Autoplay
Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Jeffrey Sack

Jeff is a Biology teacher and has a Doctorate in Educational Leadership

This lesson will define the stage of interphase during the cell cycle. The different phases of interphase and the events that occur during each will also be discussed.

What Is Interphase?

Before a cell can reproduce, it has to perform a variety of activities to get ready. The stage of the cell cycle when a cell is preparing itself to duplicate is called interphase. Since so many things are happening in the cell at this time, most of the cell's life is spent in this stage. While preparing to reproduce, the cell makes more cytoplasm (the gel-like substance found inside the cell membrane that bathes the organelles) and increases its supply of proteins. When it's ready, it goes through three sub-phases of interphase: G1, S, and G2.

Sub-phases of interphase
Interphase I

What Happens During G1?

During the G1, or gap 1, sub-phase of interphase, the cell is getting ready to move into the S sub-phase. The chromosomes in the nucleus have not yet replicated and the cell is growing. It experiences a significant increase in size. If the cell did not grow before it divided, it would ultimately become too small to function. Each cell division would make it smaller and smaller until there was nothing left of it.

G1 can vary in its length of time, depending upon the type of cell. Some cells, such as rapidly-dividing embryonic cells, do away with it altogether. This is because these cells are more concerned with how fast they can divide than making sure all of the new cells work properly. If some of these cells fail to function because they did not grow enough, there are enough of them so that the others can take up the slack.

Other cells stay in this sub-phase for weeks or years. If they are in this sub-phase for long periods of time, they enter what is called the G0 phase. This is basically a state of suspended animation. To get out of G0, special internal and external signals are needed. Once received, the cell will re-enter G1.

There is a transition step between G1 and S called the restriction point. This is the time when the cell has committed to duplicate its DNA and engage in cell division. Once it reaches this point, the cell will proceed regardless of the environmental conditions. This guarantees another cell cycle after the current one is completed.

What Happens During S?

The S sub-phase of interphase is when all of the cell's genetic material is duplicated. Each chromosome is copied and results in a pair of sister chromatids. Remember that a chromosome is a strand of DNA wrapped around proteins. These will then separate when the cell finally divides. One half will go into each new cell.

Chromosome replication happens when a DNA strand unwinds and the strands separate. Each of these strands now serves as a template for the new strands of DNA that will be formed. Free-floating nucleotides in the nucleus attach themselves to the exposed nitrogen bases of the template strand. This results in the new chromosomes being half of the original parent strand and half of the new strand. They are almost identical to the original strands. This entire process is driven by several enzymes, proteins that speed up reactions.

What Happens During G2?

The last sub-phase of interphase is called G2. It's here that the cells finish growing and prepare for mitosis. The organelles duplicate at this time and the microtubules that make the spindle fibers, which will separate the chromatids, are formed. The chromosomes condense and attach themselves to the spindle fibers. Once this happens, the cell is ready to move into the first step of mitosis and begin dividing.

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

Register for a free trial

Are you a student or a teacher?
I am a teacher
What is your educational goal?
 Back

Unlock Your Education

See for yourself why 10 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back

Earning College Credit

Did you know… We have over 49 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Click "next lesson" whenever you finish a lesson and quiz. Got It
You now have full access to our lessons and courses. Watch the lesson now or keep exploring. Got It
You're 25% of the way through this course! Keep going at this rate,and you'll be done before you know it.
1
The first step is always the hardest! Congrats on finishing your first lesson. Go to Next Lesson Take Quiz
5
Way to go! If you watch at least 30 minutes of lessons each day you'll master your goals before you know it. Go to Next Lesson Take Quiz
10
Congratulations on earning a badge for watching 10 videos but you've only scratched the surface. Keep it up! Go to Next Lesson Take Quiz
20
You've just watched 20 videos and earned a badge for your accomplishment! Go to Next Lesson Take Quiz
50
You've just earned a badge for watching 50 different lessons. Keep it up, you're making great progress! Go to Next Lesson Take Quiz
100
You just watched your 100th video lesson. You have earned a badge for this achievement! Go to Next Lesson Take Quiz
200
Congratulations! You just finished watching your 200th lesson and earned a badge! Go to Next Lesson Take Quiz
300
Congratulations! You just finished watching your 300th lesson and earned a badge! Go to Next Lesson Take Quiz
500
You are a superstar! You have earned the prestigious 500 video lessons watched badge. Go to Next Lesson Take Quiz
1K
Incredible. You have just entered the exclusive club and earned the 1000 videos watched badge. Go to Next Lesson Take Quiz
20
You have earned a badge for watching 20 minutes of lessons.
50
You have earned a badge for watching 50 minutes of lessons.
100
You have earned a badge for watching 100 minutes of lessons.
250
You have earned a badge for watching 250 minutes of lessons.
500
You have earned a badge for watching 500 minutes of lessons.
1K
You have earned a badge for watching 1000 minutes of lessons.