Busy. Please wait.

Forgot Password?

Don't have an account?  Sign up 

show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.

By signing up, I agree to StudyStack's Terms of Service and Privacy Policy.

Already a StudyStack user? Log In

Reset Password
Enter the email address associated with your account, and we'll email you a link to reset your password.

Remove ads
Don't know (0)
Know (0)
remaining cards (0)
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards

Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

LifeScience sec8

this becan whn the eath originated 4.6 billion years ago,and continued until about 540 million years ago. Precambrian time
the first true cells were called prokaryotes
prokaryotes are cells that pack a nucleus
early prokaryotic cells were anaerob
prokaryotic organisms were called cyanobacteria
cyanobacteria are pjotosynthetic organisms
as cyanobacteria carried out photosynthis they released oxygen gas into oceans
the upper atmosphere is called the ozone
uv radiation can damage DNA
Created by: OMG_Elmo