The Whole Unit

Question 1

Definition of Food Security?

Answer 1

The ability for populations to have access to food that is of sufficient quality and quantity.

Question 2

Increased food production depends on factors that control plant growth

Give examples:

Answer 2

Breeding higher yielding cultivars

Use of fertilisers

Protecting crops from pests, diseases and weeds.

Question 3

Give examples of plant crops:

Answer 3

Cereals,
Potatoes,
Root,
Legumes.

Question 4

Give examples of how farmers can make best use of the land available:

Answer 4

• Breeding higher yielding cultivars
• Resistance to pests and diseases
• Reduce competition from weeds

Question 5

Equation for photosynthesis:

Answer 5

CO2 + Water –> Glucose + Oxygen

Question 6

What absorbs Light energy?

Answer 6

Plant pigments: Chlorphyll a+b, carotene and xanthophyll

Question 7

The light energy that is not absorbed is either:

Answer 7

Transmitted OR reflected

Question 8

What is the purpose of the accessory pigments (carotene and xanthophyll)?

Answer 8

Allow greater range of wavelengths to be absorbed, and then pass the energy to chlorophyll for photosynthesis/

Question 9

Describe the electrons role within photosynthesis?

Answer 9

The absorbed light excited electrons within the pigment molecule. The electrons are then transferred to the electron transport chain which released energy to generate ATP.

Question 10

Describe stage 1: Photolysis

Answer 10

• Splitting of water into oxygen and hydrogen
• Oxygen released back into the atmosphere
• Hydrogen is bonded to co-enzyme NADP to form NADPH
• Light dependent

Question 11

What 2 components are carried through to stage 2: Carbon Fixation?

Answer 11

• CO2

- NADPH

Question 12

Describe stage 2: Carbon Fixation

Answer 12

• Temperature dependent
• co2 attaches to RUBP by enzyme rubisco to produce 3PG (intermediate compound)
• 3PG combines with NADPH hydrogen ions to form G3P which is used to regenerate RUBP which produces glucose.

Question 13

Purpose of plant and animal breeding:

Answer 13

To improve characteristics to support sustainable food production

Question 14

Breeders develop crops and animals with:

Answer 14

• Higher yield
• Higher nutritional value
• Pest and Disease resistant
• Ability to thrive in varying environmental conditions

Question 15

Describe field trails:

Answer 15

Field trials are carried out in a range of environments to compare performances of different cultivars and treatments.

Question 16

Considerations of field trials:

Answer 16

• The selection of treatment used (only one treatment can be trialed at a time)
• Number of replicates (more replicates = more reliable results)
• Randomisation of treatments (eliminates bias when measuring treatment effects)

Question 17

Describe inbreeding:

Answer 17

Related animals or plants are bred for several generations until the population breeds true to the desired type

this is due to the elimination of heterozygotes

Question 18

What does inbreeding lead to?

Answer 18

An increase in the number of individuals who are homozygous for recessive deleterious alleles - this is inbreeding depression.

Question 19

How can new alleles be introduced to a plant or animal?

Answer 19

By crossing a cultivar or breed with an individual with a different, desired genotype.

Question 20

Properties of annual weeds:

Answer 20

• Rapid growth
• Short life cycle
• high seed output
• long term seed viability

Question 21

Properties of perennial weeds:

Answer 21

• Longer life cycle
• Storage organs
• vegetive reproduction

Question 22

Cultural methods of control:

Answer 22

• Ploughing
• Weeding
• Crop rotation

Question 23

Biological methods of control and risks:

Answer 23

Use of a control agent eg: Predator or parasite of the pest

Control organism may become an invasive species

Question 24

Pesticides and disadvantages:

Answer 24

Selective: Have a greater effect on certain plant species (broad leaved weeds)

Systemic: Spread through the vascular system of plant + prevent regrowth

Disadvantages: Toxic to not target species, persistence within the environment and bioaccumulation

Question 25

Free range, advantages and disadvantages:

Answer 25

- More land needed - More labour intensive - Higher price - Better quality of life for the animals

Question 26

Intensive farming, advantages and disadvantages:

Answer 26

- Poor animal welfare - Cost effective - High profit as costs are low

Question 27

Behavioural indicators of poor welfare:

Answer 27

- Stereotypy (repetitive behaviours lacking in function eg: pacing and chewing) - Misdirected (pecking, plucking, cross-suckling in calfs) - Failure in sexual / parental behaviour - Altered levels of activity (Apathy or hysteria)

Question 28

Describe symbiosis:

Answer 28

2 different species having co-evolved intimate relationships

Question 29

Name the 2 different symbiotic relationships:

Answer 29

Mutualistic and parasitic

Question 30

Describe mutualism and give example:

Answer 30

Relationship in which both parties benefit. eg: herbivores and protozoa

Question 31

Describe parasitism:

Answer 31

Parasite benefits in terms of energy and resources, while the host is harmed by the loss of resources

Question 32

Name the 3 different methods of transmission for a parasite:

Answer 32

Vector, Direct contact and Secondary Host

Question 33

Describe a vector: (give an example)

Answer 33

Organism that transports parasite from 1 host to another Eg: Mosquito is a vector for the malaria parasite.

Question 34

Describe direct Contact: (give example)

Answer 34

Hosts having physical contact Eg: lice and ticks.

Question 35

Describe a secondary host:

Answer 35

Organism that acts as a temporary carrier of the parasite to allow completion of a life cycle.

Question 36

Describe the two different roles in social hierarchy:

Answer 36

Dominant (ritualistic threat displays) Subordinate (appeasement behaviour to reduce conflict)

Question 37

Advantages of social hierarchy:

Answer 37

- Increased chance of dominant animals favourable genes being passed on - Aggresion between group is minimised - Energy is conserved

Question 38

Advantages to co-operative hunting:

Answer 38

- Higher chance of successful kill - Larger prey caught - Less energy is used

Question 39

Describe altruism:

Answer 39

A behaviour that harms the donor but benefits the recipient Often between kin in order to keep family line of good genes

Question 40

Name the 3 components of biodiversity:

Answer 40

Genetic Diversity Species Diversity Ecosystem Diversity

Question 41

Describe genetic diversity:

Answer 41

The no. + frequency of alleles within a population.

Question 42

Describe species diversity:

Answer 42

The no. of different species in an ecosystem and proportion of each species

Question 43

Describe ecosystem diversity:

Answer 43

No, of specific ecosystems within a defines area

Question 44

Threats to biodiversity:

Answer 44

Deforestation Over exploitation Habitat Fragmentation