nitrogen cycle

Question 1

nitrates

Answer 1

found in soil, this is the only form that can by used by plants

Question 2

nitrogen gas

Answer 2

in the atmosphere, can not be taken in directly by plants or animals

Question 3

Ammonia

Answer 3

dead organisms and excreted materials are decayed into ammonia and must be converted to nitrates to be taken in by plant

Question 4

nitrogen fixing bacteria

Answer 4

converts nitrogen gas into nitrates

Question 5

nitrifying bacteria

Answer 5

converts nitrates into nitrogen gas

Question 6

Denitrifying bacteria

Answer 6

converts nitrates into nitrogen gas

Question 7

root hair cells

Answer 7

nitrates present in soil and so are absorbed by root hair cells present on the roots of plants
specialized epidermal cell that adapted by having a large surface area for the uptake of mineral ions and water

Question 8

active uptake

Answer 8

water is absorbed by osmosis as it moves from a high concentration in the soil to a low concentration in the root. Mineral ions are absorbed by active uptake as they move from low to high concentration against concentration gradient, this process requires energy. Energy is obtained from aerobic respiration requiring presence of oxygen.

Question 9

Nitrification

Answer 9

plants can only absorb nitrogen in the form of nitrates
plants and animals are eaten by other animals; they are then digested and will then build up to make other proteins in the next organism
nitrogen is then returned to the ground in form of urine or death and decay. Decay or putrefying bacteria and fungi break down proteins to release ammonia
Nitrifying bacteria are special aerobic bacteria that converts ammonia into nitrates in this process called nitrification.

Question 10

nitrogen fixation

Answer 10

process by which nitrogen in the atmosphere are converted into
performed naturally by aerobic and anaerobic bacteria
nitrogen fixing bacteria lives in nodules of some roots and plants and are present in soil, particularly in legumes.
relationship between legumes and bacteria are complex, but an important one where each partner benefits.
bacteria gains carbs from legumes and in turn they provide a source of nitrates for benefit of the plant

Question 11

Denitrification

Answer 11

process by which nitrates are converted into nitrogen gas
wasteful and undesirable process,
anaerobic and thrive in waterlogged soils, their effect on well drained, aerated soils in much reduced