the nitrogen cycle

Question 1

name 3 inorganic forms of nitrogen

Answer 1

• nitrogen gas
• ammonia
• nitrates

Question 2

name 2 organic forms of nitrogen

Answer 2

• proteins
• DNA/RNA

Question 3

how do plants obtain nitrates?

Answer 3

via active transport

Question 4

what is the role of the nitrogen cycle?

Answer 4

decomposition of dead leaves via saprophytic bacteria and conversion into ammonia via nitrification

Question 5

step 1 of the nitrogen cycle

Answer 5

nitrogen compounds in dead plants/animals are decomposed by saprophytic bacteria and fungi

Question 6

what is nitrogen fixation?

Answer 6

combining nitrogen gas and hydrogen to produce ammonia so that plants can absorb and use nitrogen

Question 7

what is azobacter?

Answer 7

a form of nitrogen fixing free living bacteria

Question 8

what is rhizobium?

Answer 8

nitrogen fixing bacteria that lives inside root nodules which have a mutualistic relationship

Question 9

how do rhizobium bacteria and the root nodules they live in have a mutualistic relationship?

Answer 9

• plant gains amino acids from rhizobium
• bacteria gain carbohydrates produced by plant during photosynthesis

Question 10

what is nitrification?

Answer 10

the process by which ammonium compounds in the soil are converted into nitrogen containing molecules that plants use

Question 11

what bacteria is involved in the nitrification of ammonium into nitrites?

Answer 11

nitrosomonas

Question 12

what bacteria is involved in the nitrification of nitrites into nitrates?

Answer 12

nitrobacter

Question 13

what is denitrification?

Answer 13

the conversion of nitrates straight back to nitrogen gas in the absence of oxygen

Question 14

what is ammonification?

Answer 14

the conversion of nitrogen containing molecules into ammonium compounds by decomposition