topic 5- nutrient cycles

Question 1

The role of saprobionts

Answer 1

Microorganisms that secrete digestive enzymes to convert organic matter into inorganic compounds

Question 2

What is ammonification?

Answer 2

dead matter or urea and faeces are decomposed by saprobionts to produce ammonium ions

Question 3

what is nitrification?

What conditions must nitrification be in and why?

Answer 3

When ammonium ions are converted into nitrites and then into nitrates

aerobic conditions. nitrifying bacteria need oxygen for nitrification and to aerobically respire themselves.

Question 4

What is denitrification?

what conditions does it require?

Answer 4

when nitrate ions are converted into nitrogen gas.

anaerobic conditions by denitrifying bacteria

Question 5

what is nitrogen fixation?

Answer 5

When nitrogen gas is converted back into ammonium by nitrogen fixing bacteria

Question 6

what are micorrhizae

Answer 6

fungi that associate with the roots of plants

Question 7

Why are micorrhizae important?

Answer 7

They increase the SA for absorption of H20 and mineral ions.
forming a mutualistic relationship

Question 8

How do micorrhizae benefit within the mutualistic relationship?

Answer 8

they receive sugars from the plant

Question 9

What is leaching?

Answer 9

when soluble nutrients are lost from soil when water drains through

Question 10

What is eutrophication?

Answer 10

leaching of XS mineral ions from fertiliser into water ways

Question 12

why is eutrophication an issue

Answer 12

increase in mineral ions means more rapid growth of algae in ponds and rivers.

algae blocks sunlight for plants below and plants can’t photosynthesise

bacteria feed on plants below and carry out aerobic respiration. they use up oxygen

less oxygen availiable for fish and other organisms