B4.1.8 Decomposers

Question 1

Decomposers

Answer 1

Microorganisms which break down/decay dead organic material/animal waste at microscopic level

Question 2

Saprophytes

Answer 2

Microorganism/plant/fungus which lives on dead or decaying material

Question 3

Detritivores

Answer 3

Small animals which speed up decomposition by shredding organic material into very small pieces, creating a larger surface are for decomposers to work on

Question 4

How do decomposers release nutrients?

Answer 4

Bacteria and fungi release enzymes which break down substances in organic matter
then absorb soluble nutrients into bodies using for growth and energy store
Then eaten=nutrients passed on
OR nutrients released directly into soil

Question 5

Which factors affect rate of decomposition?

Answer 5

• warm temperatures
• moist environments
• aerobic conditions

Question 6

How do warm temperatures affect rate of decomposition?

Answer 6

High temp = enzyme used by microorganisms denatured = no decomposition & death of microorganism
Low temp = rates of enzyme-controlled reactions slow = slow rate of decomposition & rate of microorganism replication too slow

Question 7

How do moist environments affect rate of decomposition?

Answer 7

Not enough water= slow/prevents reactions within microorganism = reduces/stops decomposition

Question 8

How do aerobic conditions affect rate of decomposition?

Answer 8

Oxygen needed for microorganism to respire = anaerobic conditions kill microorganisms = prevent decomposition

Question 9

Calculate rate of decay of biological material

Answer 9

Rate of decay (g/day)= change in mass (g)/ time (day)