The Carbon + Nitrogen Cycle

Question 1

…. fixed carbon atoms from carbon dioxide into organic compounds (e.g. glucose)

Answer 1

photosynthesis

Question 2

… passes carbon atoms from organic compounds along food chains

Answer 2

feeding and animilation

Question 3

… produces inorganic carbon dioxide from organic compounds as these are broken down to release …

Answer 3

respiration

energy

Question 4

carbon from dead organic material is released during respiration by …

Answer 4

decomposers

Question 5

… occurs when dead organic matter does not fully decay due to conditions in the soil, leading to fossil fuel formation

Answer 5

fossilisation

Question 6

…. releases carbon dioxide into the atmosphere when fossil fuels are burned

Answer 6

combustion

Question 7

what can plants and animals not fix from the air and soil directly

Answer 7

nitrogen

Question 8

explain in the nitrogen cycle what this is: assimilation

Answer 8

plants get some of their nitrogen by absorption of nitrate ions via their roots

Question 9

explain in the nitrogen cycle what this is: feeding

Answer 9

animals get all of their nitrogen (already assimilated into organic molecules e.g. protein) by feeding. on plants or other animals

Question 10

explain in the nitrogen cycle what this is: ammonification

Answer 10

decomposition by decomposers of dead plant and animal material produces ammonia from organic compounds

Question 11

explain in the nitrogen cycle what this is: nitrification

Answer 11

the ammonia is first oxidised to nitrate and then to nitrate by nitrifying bacteria

Question 12

explain in the nitrogen cycle what this is: nitrogen fixation

Answer 12

free-living nitrogen-fixing bacteria in soil or symbiotic bacteria in root nodules can fix nitrogen from the air into ammonia which is then used by the bacteria or the symbiotic plant to make amino acids and proteins

Question 13

explain in the nitrogen cycle what this is: denitrification

Answer 13

denitrifying bacteria use nitrate in the soil and convert it back into nitrogen

Question 14

why do plants and animals need nitrogen

Answer 14

proteins, amino acids, DNA, ATP

Question 15

what molecule in the atmosphere is nitrogen normally found in

Answer 15

nitrogen molecule

Question 16

which organic molecules is nitrogen found in

Answer 16

proteins, amino acids, DNA, ATP

Question 17

what inorganic molecules is nitrogen found in

Answer 17

NO2, ammonia, N2 in air + soil, NO3- nitrate in soil

Question 18

what are 2 ways that atmospheric nitrogen gets into the ground

Answer 18

lightning (N fixation) + N fixing bacteria in root nodules

Question 19

which organisms do nitrogen fixate for plants

Answer 19

N fixing bacteria in soil + denitrifying

Question 20

why dont farmers have to put nitrogen fertiliser on soybeans

Answer 20

N fixing bacteria in root nodules

Question 21

where do plant get their nitrogen from

Answer 21

air and soil

Question 22

where do primary consumers get their nitrogen form

Answer 22

feeding on plants

Question 23

where does an animals or plants nitrogen go when the animal or plant dies

Answer 23

decay into the soil, detritus

Question 24

where do secondary consumers get their nitrogen from

Answer 24

nitrogen in animal proteins

Question 25

which organisms convert ammonia into nitrate

Answer 25

nitrifying bacteria

Question 26

how is nitrogen released into the atmosphere

Answer 26

denitrification