Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


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.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
Know
remaining cards
Save
0:01
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:
Retries:
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

gcse science B4 - H

specific for ocr gateway additonal science B.

QuestionAnswer
what is carbon dioxide? a compound containing carbon
how is carbon dioxide taken out of the atmosphere? by plants for photosynthesis. carbon is then passed along the food chain when animals feed
how is carbon dioxide put back into the atmosphere? -plants and animals which respire -fungi and bacteria which respire when they decompose -burning fossil fuels such as coal and oil -erupting volcanoes and forest fires
how is carbon recycled at sea? -shells of marine organisms (e.g. molluscs) contain carbonates. -when they die, their shells turn into sedimentary rock called limestone -limestone is attacked by acid rain, giving off carbon dioxide
how much nitrogen is in the atmosphere? 78%
why do plants and animals need nitrogen? to make proteins for growth
why can't plants and animals use nitrogen directly? its inert - unreactive
how does nitrogen get into plants? in the form of nitrates
how do decomposers contribute to the nitrogen cycle? they break down proteins in dead bodies and urea into ammonia
how do nitrifying bacteria contribute to the nitrogen cycle? they convert ammonia into nitrates
how do nitrogen-fixing bacteria contribute to the nitrogen cycle? they 'fix' nitrogen by converting it into ammonia or nitrates and then into amino acids to form proteins
how does lightning contribute to the nitrogen cycle? fixes nitrogen by combining nitrogen and oxygen to form oxides. the oxides dissolve in rain and form nitrates in the soil
how do denitrifying bacteria contribute to the nitrogen cycle? convert nitrates back into nitrogen gas
Created by: jirwin