Topic 13 - Energy and Ecosystems

Question 1

Producers

Answer 1

Photosynthetic organisms that can manufacture organic substances using solar energy, water, carbon dioxide and mineral ions.

Question 2

Consumers

Answer 2

Organisms that feed on other organisms, rather than using solar energy to produce their own energy

Question 3

Primary consumers

Answer 3

Organisms that directly eat producers

Question 4

Secondary consumers

Answer 4

Organisms that eat primary consumers

Question 5

Tertiary consumers

Answer 5

Organisms that eat secondary consumers

Question 6

Saprobionts

Answer 6

A group of organisms that break down complex materials in dead organisms, into more simple molecules. They release valuable minerals and elements in a way that can be absorbed by bacteria

Question 7

Food chain

Answer 7

The feeding relationship from producers to tertiary consumers along each trophic level

Question 8

Trophic level

Answer 8

Each level of the food chain

Question 9

Food web

Answer 9

A true representation of consumption within a habitat. Unlike a food chain, this shows how energy can be transferred throughout the whole environment

Question 10

Biomass

Answer 10

The total mass of living material in a specific area at a given time. Measured in dry mass per area in a given time

Question 11

Calorimetry

Answer 11

A process in which biomass can be measured, where a sample of dry material is weighed then burned in a seal chamber in the presence of pure oxygen. Measured in kJ kg^-1

Question 12

Net primary production

Answer 12

The chemical energy store remaining once respiratory losses have been taken into account (GPP - R)

Question 13

Gross primary production

Answer 13

The total quantity of the chemical energy store in plant biomass, this does not consider the respiratory losses of the plant

Question 14

Faeces and Urine

Answer 14

Another factor which accounts for the net production of consumers, other than respiratory losses

Question 15

Percentage efficiency

Answer 15

(Energy available after energy transfer/ Energy available before energy transfer) x 100

Question 16

Movement

Answer 16

A factor that is restricted in intensive farming so that less energy is used in muscle contraction

Question 17

Temperature

Answer 17

A factor that is maintained in intensive farming so that there is less heat loss in the body

Question 18

Feeding

Answer 18

A factor that is controlled in intensive farming so that animals have maximum growth with the least wastage

Question 19

Predators

Answer 19

A factor that is removed in intensive farming so that there is no loss of organisms to the food web

Question 20

Nitrification

Answer 20

The conversion of ammonium ions into nitrate ions through a two step process involving nitrifying bacteria:
- Oxidation of ammonium ions to nitrite ions
- Oxidation of nitrite ions to nitrate ions.

Question 21

Ammonification

Answer 21

The production of ammonia from organic nitrogen containing compounds (dead material) by saprobionts, allowing for ammonium ions to form in the soil.

Question 22

Nitrogen fixation

Answer 22

The process by which nitrogen gas is converted into nitrogen-containing compounds by two different microorganisms:
- Free living bacteria that reduces gaseous nitrogen to ammonia, to process into amino acids
- Mutualistic bacteria that love in the nodules of plant roots, obtaining carbohydrates from the plant in return for amino acids.

Question 23

Denitrification

Answer 23

The process by which nitrates are converted into gaseous nitrogen. This is only done in anaerobic conditions by denitrifying bacteria.

Question 24

Deposition

Answer 24

Rain causes phosphates to be deposited in rocks

Question 25

Erosion

Answer 25

Weathering of rocks cause the release of phosphate ions into soil and water

Question 26

Absorption

Answer 26

Plants take up the phosphate ions from the soil and water

Question 27

Excretion and Decomposition

Answer 27

Once animals have taken up phosphates from consuming plants, they release the phosphate back into the water

Question 28

Excretion

Answer 28

Once animals have taken up phosphates from consuming plants, they release the phosphates back into the soil

Question 29

DNA

Answer 29

Where phosphates are incorporated into animals upon consumption of plants

Question 30

mycorrhizae

Answer 30

Associations between certain types of fungi and the roots of most plants. They act like a sponge to hold water and minerals which then allows for the fungi and plants to survive in extreme weather. These allow for a mutualistic relationship between the plants and fungi.

Question 31

Organic fertilisers

Answer 31

Fertilisers that consist of dead and decaying remains of plants and animals, including the excretion of animals

Question 32

Inorganic fertilisers

Answer 32

Fertilisers that are mined from rocks, converted into unique forms and blended for an appropriate ration of NPK

Question 33

Reduced species diversity

Answer 33

Nitrogen rich soils favour the growth of grass and other fast growing species. This increases the competition and slower growing plants die

Question 34

Leaching

Answer 34

The running of excess fertilisers into groundwater

Question 35

Eutrophication

Answer 35

Where leaching causes fertilisers to run into watercourses

Question 36

The process of eutrophication:

Answer 36

1) Excess fertiliser runs into water from leaching. Removing nitrogen as a limiting factor, allowing for the growth of plants and algae
2) Algal bloom occurs on the surface of the water, forming a dense layer of algae
3)The algae absorbs all of the solar energy, blocking the energy from reaching the lower surface
4) The lack of solar energy prevents the photosynthesis of plants - they die
5) Saprobionts utilise the deal material for food, so reproduce and use more oxygen
6) Less oxygen prevents organisms that undergo aerobic respiration from survival - they die
7) Anaerobic organisms thrive, further decomposing dead material, making the water putrid.

Question 37

What is an ecosystem

Answer 37

A biological community of interacting organisms and their physical environment. Including all the living and non living things in an area

Question 38

Cellular respiration

Answer 38

The process by which producer release their chemical energy

Question 39

What is excess chemical energy stored as in plants?

Answer 39

Starch