Key Area 1-Food Supply, Plant Growth And Productivity

Question 1

What is food security?

Answer 1

Food security concerns human access to enough good quality food

Question 2

Why is there an increasing demand for food production?

Answer 2

• world population continuing to increase

- people are concerned with food security

Question 3

What is sustainable food production?

Answer 3

Being able to produce enough food for a long period of time causing minimum destruction to land

Question 4

What is food production dependant on?

Answer 4

Photosynthesis

Question 5

The area to grow food crops is…..

Answer 5

Limited

Question 6

What are the four main foods?

Answer 6

Cereals
Legumes
Roots
Potatoes

Question 7

How can we increase food supply?

Answer 7

• reduce limiting factors
• higher yielding cultivars
• protection for pests/diseases
• reducing competition

Question 8

What are four characteristics breeders may want to develop?

Answer 8

• higher nutritional values
• pest and disease resistance
• characteristics suited to rearing and harvesting
• ability to thrive in particular environments

Question 9

Do crops or livestock give more energy?

Answer 9

Crops

Question 10

Describe efficiency of food chains

Answer 10

Longer food chains are less efficient as only 10% of energy is passed on at each stage of the food chain, therefore more energy is lost

Question 11

Why are some areas more suitable for livestock rather than plant crops?

Answer 11

Livestock can survive harsher conditions

Question 12

What is photosynthesis?

Answer 12

When plants convert light energy into chemical energy

Question 13

What is the photosynthesis equation?

Answer 13

Water + carbon dioxide ———

Glucose + oxygen

Question 14

What are the possible fates of light when it hits a leaf?

Answer 14

• absorbed
• reflected
• transmitted

Question 15

What are the three photosynthetic pigments?

Answer 15

• chlorophyll A
• chlorophyll B
• carotenoids

Question 16

What is the role of photosynthetic pigments?

Answer 16

They absorb different wavelengths of light to cause photosynthesis

Question 17

What colours do the pigments absorb?

Answer 17

Chlorophyll absorbs red and blue

Carotenoids absorb in between

Question 18

What is the absorption spectrum?

Answer 18

Shows different wavelengths of light that pigments absorb

Question 19

What is the action spectrum?

Answer 19

Shows how much photosynthesis is happening at different wavelengths

Question 20

Compare the action spectrum to the absorption spectrum

Answer 20

Both graphs show the same pattern therefore you can conclude pigments cause photosynthesis

Question 21

What is the function of carotenoids?

Answer 21

Go absorb wavelengths of light that chlorophyll cannot absorb

Question 22

What is the advantage of carotenoids?

Answer 22

They allow for more photosynthesis

Question 23

What is the first stage of photosynthesis?

Answer 23

Photolysis

Question 24

What happens to electrons in chlorophyll when light energy is absorbed?

Answer 24

They get excited

Question 25

What is released as electrons are passed along the electron transport chain?

Answer 25

Energy

Question 26

How is energy released from high energy electrons used to generate ATP?

Answer 26

It pumps hydrogen across the membrane creating a concentration gradient for ATP synthase to generate ATP

Question 27

How does energy released from electrons generate hydrogen and oxygen?

Answer 27

Energy splits water into oxygen and hydrogen

Question 28

What happens to hydrogen released?

Answer 28

Hydrogen combines with the hydrogen acceptor NADP to become reduced NADPH

Question 29

Where does photolysis occur?

Answer 29

The chloroplast

Question 30

What is the second stage of photosynthesis?

Answer 30

The Calvin cycle

Question 31

What does carbon dioxide combine with?

Answer 31

Ribulose biphosphate (RuBP)

Question 32

What enzyme catalyses the reaction?

Answer 32

Rubisco

Question 33

How does RuBP split?

Answer 33

Splits into two 3c:

3-phosphoglycerate

Question 34

What is ATP from photolysis used for?

Answer 34

To add a hydrogen to 3-phosphoglycerate to make G3P

Question 35

What can become of G3P?

Answer 35

• can regenerate into RuBP

- joins with another G3P to make glucose

Question 36

What are the three fates of glucose?

Answer 36

• stored as starch
• energy for respiration
• structural cellulose

Question 37

What is biomass?

Answer 37

The total dry mass of a particular organism

Question 38

What is net assimilation?

Answer 38

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

Question 39

What is productivity?

Answer 39

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

Question 40

What is lead area index?

Answer 40

As the size of the leaf increases, the productivity increases until leaves are too large that they shade lower leaves and productivity levels off

Question 41

What is harvest index?

Answer 41

A calculation that divides the economic yield by the biological yield (usually converted into a percentage)

Question 42

What is biological yield?

Answer 42

The total biomass of a crop plant, e.g.-whole potato plant including stem and leaves above ground

Question 43

What is economic yield?

Answer 43

The total biomass of the desired product of the plant, e.g.- just the potatoes