5. Use Of Biological Resources

Question 1

What are the factors that effect photosynthesis !?

Answer 1

Light intensity

Carbon dioxide concentration

Temperature

Question 2

Rate of photosynthesis + light intensity graph:

Answer 2

Question 3

Rate of photosynthesis + **carbon dioxide concentration ** graph:

Answer 3

Question 4

Rate of photosynthesis + temperature graph:

Answer 4

Question 5

Why do farmers choose to grow crops in greenhouses?

Answer 5

In open fields, it is very difficult to control the factors that affect the rate of photosynthesis within greenhouses farmers can have control over these factors

Question 6

What can farmers control within greenhouses!?

Answer 6

. Temp - artificial heating

. Light intensity– artificial lighting

. Carbon dioxide concentration – additional carbon dioxide in the air

. Regular watering

Question 7

What do greenhouses and polythene tunnels provide for plants !?

Answer 7

Greenhouses and polythene tunnels, provide enhanced conditions for plants to grow

Question 8

How to greenhouses and polythene tunnels, provide enhanced light intensity!?

Answer 8

The transparent material allows sufficient natural light in the photosynthesis during the summer

Artificial lighting gives a “longer day” during the winter for valuable crops.

Question 9

How to greenhouses and polythene tunnels, provide enhanced temperature!?

Answer 9

The greenhouse effect also raises the temperature in glasshouses

Burning fossil fuels or wood raises the temperature when the external temperature is too low. It also produces carbon dioxide and water vapour

Question 10

Why is water vapour important in greenhouses and polythene tunnels? 

Answer 10

Water vapour maintains a moist atmosphere, so reduces water loss by transpiration

Question 11

What must the farmer find in order to make sure that the additional cost of providing conditions are weighed against the extra profit provided by the increased yield !?

Answer 11

Define almost find the optimum conditions

Question 12

How do nitrates increase crop yield !?

Answer 12

Nitrates are needed for proteins

Question 13

How does magnesium increase crop yield !?

Answer 13

Magnesium is needed for the production of chlorophyll

Question 14

What is organic fertiliser made from!?

Answer 14

Organic fertiliser is made up from the faces of a range of animals, sometimes mix with straw.

Also compost from legumes such as clover.

Question 15

What is inorganic fertiliser made from!?

Answer 15

Inorganic fertiliser is composed of inorganic compounds carefully formulated to yield a specific concentration of a particular ion when applied according to the manufacturer’s instructions

Question 16

What are the advantages of organic fertiliser?

Answer 16

Improves soil structure

Greater range of minerals

Release is minerals over a longer period of time

Less cost a farmer (already available on the farm)

Question 17

What are the disadvantages of organic fertiliser?

Answer 17

Slow acting- has to be decomposed first

Bulkier, so more difficult than inorganic fertilisers to apply

May contain pests

Question 18

What are the advantages of inorganic fertiliser?

Answer 18

Mineral ions are released immediately so fast acting

Contents known

Easy to apply

Question 19

What are the disadvantages of inorganic fertiliser?

Answer 19

Can lead to eutrophication as fertiliser is soluble

Requires regular Reapplication

Question 20

What is another way, bar fertiliser, to replace lost nitrates in fields !?

Answer 20

Another way to replace lost nitrate is to grow a a legume crop, such as clover, in a field one year in four

Question 21

Why areleguminous plants a good way to replace lost nitrates in fields !?

Answer 21

These plants have nitrogen-fixing bacteria in nodules on their roots. They convert nitrogen gas in the air into ammonium ions.

This is passed to the plants which use it to make proteins

Question 22

What happens after the leguminous crop is ploughed in?

Answer 22

When the crop is ploughed in and the protein in the crop and bacteria is broken down (decomposed) ammonium is released into the soil.

This ammonium is in converted to nitrate by nitrifying bacteria and is a level for the next years crops.