ecology - decomposition

Question 1

what happens with compost heap?

Answer 1

gardeners put dead plant material like grass into it and over time bacteria and fungi decompose the plant material and produce compost

Question 2

what do farmers use the compost for? why?

Answer 2

natural fertiliser as it is very rich in the minerals that plants need to grow

Question 3

what are the optimal conditions for decomposition?
first condition = t_________. explain?

Answer 3

• temperature. takes place faster at warmer temperatures as the decomposers use enzymes to break down the plant materials. these work faster in warm conditions. compost heaps warm anyway as decomposers release energy when they carry out aerobic respiration. however it’s important it doesn’t get too hot as the enzymes in decomposers can denature and decomposers will die

Question 4

what are the optimal conditions for decomposition?
second condition = w_____. explain

Answer 4

amount of water
decomposing microorganisms work faster is the compost is moist as many of the chemical reactions in decay require water. This means it is important that gardeners do not allow a compost heap to dry out

Question 5

what are the optimal conditions for decomposition?
third condition= o______. explain?

Answer 5

amount of oxygen
decomposers carry out aerobic respiration which requires a good supply of oxygen. compost bin has holes in wall to let oxygen enter and many gardeners use gardening fork to mix compost regularly to allow more oxygen to pass into the centre. mixing compost also breaks up large clumps of+ increases surface area for decomposers to act on

Question 6

what happens if no oxygen present in compost?

Answer 6

the decomposing microorganisms carry out anaerobic decay which produces a mixture of gases such as methane. this is called a biogas.

Question 7

what do small scale biogas generators do and use?

Answer 7

to provide fuel for homes and often use plant materials such as food waste or cow manure