Nutrient cycles

Question 1

Nutrient

Answer 1

A substance used by an organism to survive, grow and reproduce

Question 2

Saprobionts

Answer 2

Decomposers like bacteria and fungi which break down dead material and absorb to use the nutrients

Question 3

Saprobiotic nutrition

Answer 3

When a saprobiont secretes enzymes out of cell that will digest the dead material and absorb the nutrients produced
In external, digestion

Question 4

Left over nutrients from saprobiotic nutrition is…

Answer 4

Left behind in soil for other organisms

Question 5

Nitrogen cycle

Answer 5

How nitrogen moves and is recycled in ecosystems

Question 6

Dead material containing nitrogen eg DNA and protein is…

Answer 6

Decomposed by saprobionic nutrition and released as ammonium ions

Question 7

Ammonification

Answer 7

Decomposition of dead material by saprobionts releases ammonium

Question 8

Ammonium is converted to what..?

Answer 8

Nitrite then nitrate

Question 9

Nitrification

Answer 9

Oxidation of ammonium to nitrite then nitrate ions by nitrifying bacteria

Question 10

What completes nitrification of ammonium?

Answer 10

Nitrifying bacteria

Question 11

What converts nitrate back to N2 gas for the atmosphere?

Answer 11

Denitrifying bacteria

Question 12

Reduction of nitrates to nitrogen process is called…

Answer 12

Denitrification

Question 13

Nitrates in soil use

Answer 13

Enter plant roots via active transport to form proteins/DNA

Question 14

Process which converts nitrogen gas in atmosphere back to ammonium ions?

Answer 14

Process called nitrogen fixing

Question 15

What converts nitrogen gas to ammonium ions in nitrogen fixing?

Answer 15

Nitrogen fixing bacteria

Question 16

Where does nitrogen fixing bacteria live?

Answer 16

In root nodules of legume plants

Question 17

Denitrifying bacteria lives best in…

Answer 17

Anaerobic soils

Question 18

What causes anaerobic soils?

Answer 18

Water logging which reduces air packets in soil

Question 19

What bacteria works best under aerobic conditions?

Answer 19

Nitrifying bacteria
Nitrogen fixing bacteria

Question 20

What causes aerobic soil?

Answer 20

Ploughing

Question 21

Phosphate ions usage

Answer 21

In ATP/ADP
in RNA/DNA

Question 22

How does the phosphate cycle start?

Answer 22

Saprobionts externally digest dead material eg dna from animals/plants which releases phosphate into the soil

Question 23

Where does the phosphate released into soil to?

Answer 23

Leeched into water bodies
Absorbed back into plants

Question 24

Phosphate leeched into water…

Answer 24

In solution and then Enters aquatic foodwebs
The dead material sinks to form sediments at the bottom

Question 25

Sediments containing phosphate ions will rise to the surface..

Answer 25

Then weather down to release phosphate back to soil

Question 26

Phosphate ions in solution in soil will..

Answer 26

Enter plant roots via active transport Used for dna etc then enters foodwebs by being eaten by animals which eventually die and cycle continues

Question 27

What is a Mycorrhizae?

Answer 27

An association between a fungus and a plant root

Question 28

How does the fungus in a mycorrhizae help?

Answer 28

Acts as an extension of the root so increases surface area of root so can absorb more nutrients AND WATER (nitrate and phosphate ions) from soil to give to the plant for more growth: making proteins And DNA/ATP/RNA

Question 29

How does the plant of the root in a mycorrhizae help the fungus?

Answer 29

Shares its organic substances from photosynthesis eg glucose with it so can aerobically respire more