Topic 7 Higher

Question 1

How does temperature affect the rate of decomposition?

Answer 1

• initially as the temperature increase the rate of decomposition
• as the temperature becomes very high the Decomposers may die and the enzymes they produce may be denatured

Question 2

How does oxygen affect the rate of decomposition

Answer 2

• the more oxygen there is the faster the rate of decomposition
• more oxygen means Decomposers can complete more respiration

Question 2

How does water affect the rate of decomposition

Answer 2

• more water the higher the rate if decomposition

Question 3

What are biogas generators

Answer 3

Microorganisms that can do anaerobic respiration

Question 4

What does anaerobic respiration of waste produce

Answer 4

Methane gas

Question 5

Explain the steps to test how temperature affects decomposition in milk

Answer 5

• set the temp of a water bath to 5 degrees
• add 5cm^3 of lipase into a boiling tube
• add 5cm^3 of milk to a boiling tube
• add a few drops of cresol red to the milk
• place both boiling tubes into the water bath and leave until the milk reaches the temp of the water bath
• add 1cm^3 or lipase and milk to a separate test tube and start the timer
• top the timer when the solution turns yellow
• repeat for 10, 20, 30, 49 degrees

Question 6

What is cresol red an indicator for

Answer 6

Milk

Question 7

What is an apex predator?

Answer 7

Carnivores with no predators

Question 8

Why is some biomass lost between tropic levels?

Answer 8

• not all ingested material is absorbed, some is lost as faeces
• some absorbed material is lost as waste such as water in respiration or in water and urea in urine

Question 9

What % of biomass is transferred between producers and primary consumers

Answer 9

1%

Question 10

What % of biomass is transferred between tropic levels above producers?

Answer 10

Around 10%

Question 11

What factors affect food security?

Answer 11

• increases birth rate
• changing diets
• new pests and pathogens
• the cost of agricultural inputs
• conflicts

Question 12

What is food security?

Answer 12

Having enough food to feed a population

Question 13

How can the efficiency of food production be improved

Answer 13

• limiting the movement of animals
• controlling the temperature of surroundings
• feeding high protein diets to increase growth

Question 14

What can be put in place to prevent over fishing?

Answer 14

• controls on net size (prevent the capture of small fish)
• fishing quotas