19.3 Nutrient cycles

Question 1

Nitrogen fixation

Answer 1

• nitrogen fixing bacteria is required
• takes place in soil or root nodules of legumous plants
• convert N2 into NH3

Question 2

Nitrification

Answer 2

• requires nitrifying bacteria
• takes place in soil
• converts NH3 to NO2/NO3

Question 3

absorption by active transport

Answer 3

• in plants
• on the root hair cells
• absorption of nitrates by active transport

Question 4

amino acid and protein production

Answer 4

• in plant cells
• converts nitrates (NO3) into plant proteins (CHON)

Question 5

Denitrification

Answer 5

• denitrifying bacteria
• occurs in the soil
• converts nitrates (NO3) to N2

Question 6

haber process

Answer 6

Converts N2 into NH3
(N2 + 3H3 <–> 2NH3)

Question 7

lightning

Answer 7

converts N2 into NO3