Key Area 1-Food Supply, Plant Growth And Productivity Flashcards Preview

Biology: Unit 3 > Key Area 1-Food Supply, Plant Growth And Productivity > Flashcards

Flashcards in Key Area 1-Food Supply, Plant Growth And Productivity Deck (43):
1

What is food security?

Food security concerns human access to enough good quality food

2

Why is there an increasing demand for food production?

-world population continuing to increase
-people are concerned with food security

3

What is sustainable food production?

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

4

What is food production dependant on?

Photosynthesis

5

The area to grow food crops is.....

Limited

6

What are the four main foods?

Cereals
Legumes
Roots
Potatoes

7

How can we increase food supply?

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

8

What are four characteristics breeders may want to develop?

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

9

Do crops or livestock give more energy?

Crops

10

Describe efficiency of food chains

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

11

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

Livestock can survive harsher conditions

12

What is photosynthesis?

When plants convert light energy into chemical energy

13

What is the photosynthesis equation?

Water + carbon dioxide ———
Glucose + oxygen

14

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

-absorbed
-reflected
-transmitted

15

What are the three photosynthetic pigments?

-chlorophyll A
-chlorophyll B
-carotenoids

16

What is the role of photosynthetic pigments?

They absorb different wavelengths of light to cause photosynthesis

17

What colours do the pigments absorb?

Chlorophyll absorbs red and blue
Carotenoids absorb in between

18

What is the absorption spectrum?

Shows different wavelengths of light that pigments absorb

19

What is the action spectrum?

Shows how much photosynthesis is happening at different wavelengths

20

Compare the action spectrum to the absorption spectrum

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

21

What is the function of carotenoids?

Go absorb wavelengths of light that chlorophyll cannot absorb

22

What is the advantage of carotenoids?

They allow for more photosynthesis

23

What is the first stage of photosynthesis?

Photolysis

24

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

They get excited

25

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

Energy

26

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

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

27

How does energy released from electrons generate hydrogen and oxygen?

Energy splits water into oxygen and hydrogen

28

What happens to hydrogen released?

Hydrogen combines with the hydrogen acceptor NADP to become reduced NADPH

29

Where does photolysis occur?

The chloroplast

30

What is the second stage of photosynthesis?

The Calvin cycle

31

What does carbon dioxide combine with?

Ribulose biphosphate (RuBP)

32

What enzyme catalyses the reaction?

Rubisco

33

How does RuBP split?

Splits into two 3c:
3-phosphoglycerate

34

What is ATP from photolysis used for?

To add a hydrogen to 3-phosphoglycerate to make G3P

35

What can become of G3P?

-can regenerate into RuBP
-joins with another G3P to make glucose

36

What are the three fates of glucose?

-stored as starch
-energy for respiration
-structural cellulose

37

What is biomass?

The total dry mass of a particular organism

38

What is net assimilation?

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

39

What is productivity?

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

40

What is lead area index?

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

41

What is harvest index?

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

42

What is biological yield?

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

43

What is economic yield?

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