nutrient cycle

Question 1

How do saprobionts function?

Answer 1

-feed on dead organisms and waste products - a type of decomposed which recycle chemical elements
-secrete enzymes to digest their food externally then absorb the nutrients -extracellular digestion
-during this process organic molecules are broken down into inorganic molecules

Question 2

What is saprophytic nutrition?

Answer 2

The obtaining of nutrients from dead organic matter/ waste using extracellular digestion

Question 3

Describe the process of nitrogen fixation.

Answer 3

• nitrogen gas is turned into nitrogen-containing compounds
  -carried out by nitrogen fixing bacteria such as rhizobium found in root nodules of leguminous plants.
  -converts nitrogen into ammonia
  -the plant then uses this to produce amino acids/proteins
  -mutualistic relationship- the plant is provided with nitrogen compounds and the bacteria is provided with carbohydrates

Question 4

What is a mutualistic relationship?

Answer 4

A type of relationship where both species benefit

Question 5

Describe the process of ammonification.

Answer 5

-saprobionts(bacteria) decompose proteins(from dead organisms/waste) into ammonia

Question 6

Describe the process of nitrification.

Answer 6

-when ammonia ions in the soil are changed into nitrates- which can then be used by plants
-first one type of nitrifying bacteria change ammonia into nitrites
-then another those of nitrifying bacteria convert nitrites into nitrates

Question 7

Describe the process of denitrification.

Answer 7

-nitrates converted into nitrogen gas by denitrifying bacteria - they use nitrates for respiration and produce N2
-this happens under anaerobic conditions

Question 8

What is the impact of lightening on nitrogen?

Answer 8

Can fix nitrogen into nitrogen oxides

Question 9

What is the impact of fertilisers on soil?

Answer 9

Can add nitrogen containing compounds into the soil

Question 10

What is mycorrhizae?

Answer 10

-fungi made up of long thin strands called hyphae, which connect to the plant’s roots
-the hyphae increase the SA - absorption of water and minerals for the plant
-the hyphae in turn obtain organic compounds from the plant such as glucose

Question 11

What is phosphorus used for?

Answer 11

Needed to make biological compounds such as phospholipids, ATP, and DNA

Question 12

Where is phosphorus found?

Answer 12

-found in rock and dissolved oceans in the form of phosphate ions(PO4 3-)

Question 13

What happens to phosphate ions dissolved in water?

Answer 13

Phosphate ions dissolved in water in the soil can be assimilated by plants and other producers