Ecology: Nitrogen Cycle, Minerals And Eutrophication Flashcards Preview

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Flashcards in Ecology: Nitrogen Cycle, Minerals And Eutrophication Deck (25):
1

Plants and nitrogen

Plants absorb nitrogen in form of nitrates. They then convert into amino acids and then made into protein to help plant grow.

Nitrogen cycle relies on bacteria

2

Decay

Feeds on dead organisms and waste materials releasing ammonia

3

Nitrifying

Convert ammonia to nitrates

4

Denitrifying

Convert nitrates to nitrogen gas

5

Nitrogen fixing

Convert nitrogen gas into nitrates

6

Decay, nitrifying and nitrogen fixing

bacteria all require oxygen to function efficiently.

This is why well aerated soils are important to farmer when growing crops

7

Denitrification

Reduces amount of nitrate in soil. Denitrifying bacteria prefer anaerobic conditions(no oxygen)
Such as those created due to water logging following prolonged periods due to heavy rain

8

Root hairs cells

All minerals are absorbed from the soil in solution via these roots

9

Major adaptation in root hair cells

The adaptation is the presence of an extension of the cell that projects outwards from the cell into the soil.
This greatly increases the surface area of the cell improving the rate of water and mineral absorption

10

Active uptake

The process of absorbing minerals from soil relies on active uptake.
This process moves substances against the concentration gradient.
Active uptake requires energy from respiration. This is why roots must have a sufficient supply of oxygen (glucose)

11

Nitrates

Growth and development:Needed to make amino acids the building blocks of protein

Deficiency:stunted growth

12

Calcium

Growth and development: a component of cell walls

Deficiency: no growth at all, new cells can't form

13

Magnesium

Growth and development: a compliment of the chlorophyll molecules

Deficiency: leaves appear yellowed

14

Natural fertilisers advantages

-less soluble than artificial fertiliser so less will be lost by leaching and runoff into waterways
-improves soil quality by adding to the humus content of the soil

15

Natural fertilisers disadvantages

-difficult to store and spread
-difficult to know the mineral composition exactly

16

Artificial fertiliser advantages

-easier to stores
-can be applied in a more controlled manner

17

Artificial fertiliser disadvantage

-soluble so can be easily washed away creating pollution problems
- has to be purchased

18

Slurry

Faeces and urine from farm animals (usually cattle)

19

Compost

Food waste (vegetable peelings)

20

Manure

Animal faeces

21

Eutrophication

This is where no life exist due to lack of oxygen. It is a common form of water pollution found close to agricultural land.
It often follows a sudden increase in concentration of minerals in water. ( fertiliser runoff due to heavy rain)

22

Problem with the growth of algae

The presence of minerals lead to increase rate of growth.
These form a blanket like layer on the surface if the after preventing light from reaching plants beneath. These plants eventually die.
The decomposition of these plants uses up (DEPLETES) oxygen in the water and means fish and animals cannot survive in the water.

23

How to reduce eutrophication

-use natural fertiliser
-apply when dry/don't use it when heavy rain is forecast
-don't apply close to river or ditch
-only use when necessary

24

Other pollutants which has the same effect as fertiliser runoff

Household sewage

25

Why is eutrophication more common in slow moving water (ponds)

The minerals become more concentrated