Unit 3 - Key Area 1

Front 1

Define the term food security

Back 1

Concerns human access to enough food of a good quality

Front 2

State two reasons why there is an increased demand for food

Back 2

The world population continues to increase and people are concerned with food security.

Front 3

Describe what is meant by the term sustainable food production

Back 3

Causing no harm to the land, natural resources or the water supply in a way which will last

Front 4

State the process of food production is dependent on

Back 4

Photosynthesis

Front 5

State four examples of food crops

Back 5

Potatoes

legumes

roots

cereals

Front 6

How can food production be increased regarding limiting factors

Back 6

Factors are added to ensure that growth is not limited

Front 7

How can food crop production be increased by using higher yielding cultivar

Back 7

Using varieties which are larger or produce more

Front 8

State four characteristics breeders may want to develop in food crops

Back 8

Higher nutritional values.

pest and disease resistance.

physical characteristics suited to rearing and harvesting.

ability to thrive in particular environments.

Front 9

Explain why livestock produce less food per unit area than plant crops

Back 9

The food chain is longer causing more energy to be lost at each stage shorter food chains are more efficient.

Front 10

Explain why some areas are more suitable for livestock production than crop production.

Back 10

As it is sometimes not possible to grow crops in an environment EG Hills

Front 11

Define the term photosynthesis

Back 11

The process by which green plants trap light energy and use it to produce carbohydrates.

Front 12

State the word equation for photosynthesis

Back 12

Water + carbon dioxide ---> glucose + oxygen

Front 13

State the three possible fates of light when it hits a leaf

Back 13

Absorption

reflection

transmission

Front 14

Name three photosynthetic pigments

Back 14

Chlorophyll a

chlorophyll b

carotenoids

Front 15

Describe the role of the photosynthetic pigments

Back 15

To absorb light at different wavelengths.

Front 16

Define the term absorption spectrum

Back 16

A graph that shows the different range of photosynthetic pigments.

Front 17

State which wavelengths of light are absorbed by each pigment

Back 17

Chlorophyll A and B absorb red and blue

caronenoids absorb orange green and yellow

Front 18

Define the term action spectrum

Back 18

The rate of a physiological activity plotted against wavelength of light. it shows which wavelength of light is most effectively used in a chemical reaction

Front 19

Compare the action spectrum and absorption Spectrum for photosynthesis

Back 19

They show the same pattern proving that the pigments are responsible for photosynthesis.

Front 20

Describe the advantage of having accessory pigments

Back 20

It extends the range of wavelengths that the plant can use for photosynthesis

Front 21

Name the first stage of photosynthesis

Back 21

Photolysis

Front 22

Describe what happens to electrons in chlorophyll when light energy is absorbed

Back 22

They become excited

Front 23

Explain how energy released from electrons is used to generate hydrogen and oxygen

Back 23

Energy from the electrons is used to split water into oxygen and hydrogen

Front 24

State what is released as electrons are passed along an electron transport chain

Back 24

Energy

Front 25

Explain how energy released from electrons is used to generate ATP

Back 25

Hydrogen ions are pumped across the membrane which creates an ingredient for ATP synthase to generate ATP

Front 26

State what happens to the hydrogen and oxygen released

Back 26

Oxygen is released and hydrogen bonds with the hydrogen acceptor NADP to become reduced NADPH

Front 27

Name the second stage of photosynthesis

Back 27

Calvin cycle

Front 28

What is the role of carbon dioxide in the Calvin cycle

Back 28

Carbon dioxide enters the cycle by becoming attached to the RuBP this chemical reaction is catalysed by the enzyme RuBisCO

Front 29

What is the role of 3 - phosphoglycerate in the Calvin cycle

Back 29

The 3-phosphoglycerate that is formed combines with hydrogen from NADPH and becomes phosphorylated by receiving an inorganic phosphate (Pi) from ATP which supplies the energy to drive the process

Front 30

Describe the role of G3P in the Calvin cycle

Back 30

Some G3P is used to regenerate RuBP, the carbon dioxide acceptor, the remaining G3P is used for the synthesis of sugars.

Front 31

State three possible fates of sugar produced

Back 31

Stored as starch.

used as glucose for respiration.

Used as structure as cellulose.

Front 32

Define the term biomass

Back 32

The total dry mass of a particular organism

Front 33

Net assimilation

Back 33

The overall gain in dry mass of a plant due to photosynthesis - the loss in mass due to respiration

Front 34

Productivity

Back 34

The rate at which plants generate new biomass measured in unit area per unit time

Front 35

Leaf area index

Back 35

Ratio showing the total area of the leaf to the area of ground covered by the leaf.

As the Leaf area index increases productivity increases until leaves are so large that they shade lower leaves and productivity levels off

Front 36

Biological yield

Back 36

The total biomass over crop plant EG the whole potato plant including stem and leaves above ground.

Front 37

Economic yield

Back 37

The total biomass of the desired product of the plant EG just the potatoes

Front 38

Harvest index

Back 38

A calculation that divides the economic yield by the biological yield, usually converted a percentage