Unit 2 - Key Area 3 (Biosphere)

Question 1

What is parent material?

Answer 1

The bedrock from which soil is formed

Question 2

Name the five inputs of soil:

Answer 2

• Parent material
• Organisms
• Relief
• Climate
• Time

Question 3

Chemical weathering

Answer 3

Breakdown of rock by chemicals like acids (acid rain/carbonic acid)

Question 4

Biological weathering

Answer 4

Breakdown of rocks by organism growth (trees in crack of rock)

Question 5

Physical weathering

Answer 5

Breakdown of rocks due to physical changes (freezethaw on rock surface)

Question 6

Name two decomposers

Answer 6

Fungus and bacteria

Question 7

What is leaching (in terms of soil)?

Answer 7

Leaching is movement of ions or minerals through the soil (forms aluminium or iron layers)

Question 8

What is the composition of a Brown Earth soil?

Answer 8

• Soil is very mixed, no distinct layers
• Lots of macroinvertebrates (Earthworms) in soil
• Large layer of nutrient rich humus
• Found in areas of deciduous forest

Question 9

A biofuel obtained by heating dried biomass in an oxygen-free environment. Also known as pyrolysis oil

Answer 9

Bio-crude oil

Question 10

A diesel fuel derived from oils and fats in animals or plants?

Answer 10

Biodiesel

Question 11

An alcohol made by fermentation of carbohydrates from plant

materials. It can be mixed with petrol as a fuel for vehicles

Answer 11

Bioethanol

Question 12

Give the definition for biofuel

Answer 12

Combustible biomass or a fuel derived from biomass.

Question 13

What is biogas?

Answer 13

Gas produced through the fermentation of organic matter

Question 14

What is decomposition?

Answer 14

The breaking down of organic materials into smaller parts, especially by the action of decomposers

Question 15

Layers of soil

Answer 15

Horizons

Question 16

Layer of Aluminium/Iron in a Podzol soil

Answer 16

Elluvial layer (E-horizon)

Question 17

Movement of soil materials from the E-horizon to lower in the soil

Answer 17

Illuviation

Question 18

Advantage of biofuel use

Answer 18

-Less CO2 emissions
-Stable in terms of economy and fuel availability in the future
-Renewable
Easy to source and produce

Question 19

Disadvantage of biofuel use

Answer 19

• Could be used as food source
• Not as much energy released per unit
• High cost of production
• Monoculture (reduces plant biodiversity)
• Large quantities of water used