B17.3 - The Carbon Cycle + B17.4 - Decay (Finished)

Question 1

How is carbon in the carbon cycle removed from the atmosphere?

Answer 1

CO2 is removed from the atmosphere by green plants and algae during photosynthesis

Question 2

Where is carbon stored in the carbon cycle after being removed from the atmosphere as co2?

Answer 2

Carbon removed from the atmosphere by plants as co2 is used to make glucose, turned into carbohydrates, fats and proteins making up plants matter

Question 3

Where can carbon stored in plants go to next in the carbon cycle and how?

Answer 3

• When plants respire some carbon is returned to the atmosphere as co2
• When plants are eaten by animals, some carbon becomes part of fats and proteins in their bodies
• When plants die they are decayed by microorganisms which release carbon as co2 to the atmosphere
• Products made form plants contain carbon from them

Question 4

Where does carbon stored as fossil fuels in the carbon cycle come from?

Answer 4

Carbon stored as fossil fuels comes from decayed plant and animal matter forming them

Question 5

Where does carbon go next in the carbon cycle from carbon compounds in plant eating animals?

Answer 5

• It can move up food chains (to more animals)
• It is returned to the atmosphere as co2 when they respire
• It can be returned to atmosphere by micro-organisms that are decaying them or the waste they produce
• It can form fossil fuels

Question 6

How can carbon be returned to the atmosphere from fossil fuels or products?

Answer 6

Buy burning releasing co2 a

Question 7

What are the main stores in the carbon cycle?

Answer 7

Carbon compounds in plants, carbon compounds in animals, co2 in the air, products made from plants and animals, fossil fuels, decaying matter (death + waste)

Question 8

What is compost?

Answer 8

Compost is decomposed organic matter used as a natural fertiliser for crops and garden plants

Question 9

What factors affect the rate of decay?

Answer 9

Oxygen availability, water availability, decay organism number, temperature

Question 10

What are responsible for decomposition?

Answer 10

Bacteria, fungi and detritus feeders

Question 11

What are detritus feeders?

Answer 11

Other animals that feed on dead plants and animals

Question 12

Why and how does temperature affect rate of decomposition?

Answer 12

Warmer temperatures make thing decompose quicker since they increase the rate at which decomposition enzymes work. But if it is too hot, organisms die and enzymes are destroyed so decomposition slows down or stops. Too cold and decomposition slows too

Question 13

Why does oxygen availability affect rate of decomposition?

Answer 13

Many organisms need oxygen to respire to survive. However those involved in anaerobic decay don’t

Question 14

Why does water availability increase rate of decay?

Answer 14

Rate of decay increases in moist environments as organisms involved in decay need water to carry out biological processes

Question 15

Why do gardeners and farmers try to provide optimum conditions for decay?

Answer 15

Gardeners and farmers try to provide optimum conditions for rapid decay of waste organic matter as compost produced is a useful natural fertiliser

Question 16

What is biogas made of?

Answer 16

Biogas is made up mainly of methane

Question 17

What types of microorganisms are used to produce biogas?

Answer 17

Organisms that decay plant and animal waste anaerobically are used to make biogas as this type of decay makes methane

Question 18

What is the name of the fermenter used to make biogas?

Answer 18

A digester or generator

Question 19

What is the problem(s) with biogas generation?

Answer 19

• Biogas generators need to be at a constant temperature to keep organisms respiring
• Biogas can’t be stored as a liquid I(needs too much pressure) so it has to be used straight away

Question 20

What two types of biogas generator are there?

Answer 20

Batch generators and continuous generators

Question 21

How are batch biogas generators operated?

Answer 21

Batch biogas generators are used to make biogas in small batches. They are manually loaded up with waste, left to digest, and products are cleared away at the end of each session.

Question 22

How are continuous biogas generators operated?

Answer 22

Continuous biogas generators make biogas all the time, waste is continually fed in and biogas is produced at a steady rate

Question 23

What 3 things does a biogas generator need?

Answer 23

1) An inlet for waste material
2) An outlet for digested material to be removed
3) An outlet for biogas to be piped through where needed