Mock Paper 3

Question 1

Enzyme immobilisation

Answer 1

• Concentration of substrate can be increased as the enzyme is not dissolved (increases the rate of reaction.)
• Recycled enzymes can be used many times (resulting in cost saving)
• Stability of the enzyme to changes in temperature in pH is increased, reducing the rate of degradation (results in cost saving)

Question 2

What is the use of a tap and reservoir in a transpiration lab?

Answer 2

• Used to reset the experiment by adjusting the meniscus

Question 3

How can a transpiration lab measure the effect of air movement?

Answer 3

• The more the bubble has moved the higher, the rate of transpiration
• Bubble is reset after experimental trials
• Fan is used to blow air on the leaves

Question 4

What are limitations to using a Potometer?

Answer 4

• assumes water only used in transpiration when you can also be used in photosynthesis
• Measures water uptake

Question 5

What did William Harvey discover?

Answer 5

• Blood flows to the heart
• Blood flows in One Direction (depending on blood vessels)
• Valves prevent backflow

Question 6

How is phosphorus produced?

Answer 6

Leaching
Run off
Erosion

Question 7

Significance of phosphorus

Answer 7

• Can be used as a fertiliser
• A decrease in phosphate would result in a lower yield of crops

Question 8

Outline the purpose of a Gersmehl diagram

Answer 8

• shows the differences in nutrient flow and storage between different types of ecosystems
• Biomass is the total mass of living organisms
• Litter is any organic matter in and on the soil
• Soil is the top layer of the Earth
• Nutrients can be transferred from biomass to litter (fallout) litter, to soil (decay) or soil to biomass (uptake)
• arrows indicate nutrient flow

Question 9

Differences between taiga and tropical rainforests

Answer 9

• Most nutrients stored as biomass in tropical rainforests
• Most nutrients are stored as litter in taiga
• More decomposers in a rainforest
• High rainfalls result in decomposition of litter

Question 10

Exsitu

Answer 10

Preservation of a species outside their natural environment

Question 11

Insitu

Answer 11

Preservation of a species in their natural habitat

Question 12

What is competitive exclusion?

Answer 12

• No to species can occupy the same niche for extended periods of time
• One species will have an advantage over the other
• Competition for resources
• The less well adapted species will be eliminated

Question 13

What are keystone species?

Answer 13

Species that has a disproportionately large impact on the environment, relative to its abundance

Question 14

Capture Mark, release recapture sampling

Answer 14

• organisms are captured and marked
• Released back into nature
• an area is defined and marked off
• In recapture, both on marked and unmarked organisms are counted
• Lincoln index is used to estimate population size
• Marking should not affect organisms survival