B6.2

Question 1

What is food security?

Answer 1

Ability of human population to access affordable food of sufficient quality and quantity

Question 2

What factors affect food security?

Answer 2

• increasing human population
• changing diets (richer people eat a varied diet with meat that is energy intensive to produce than plants products)
• climate change means more droughts and deserts will expand, but increase in CO2 can mean increased yield of crops
• New pests and pathogens may evolve

Question 3

How can food production be increased?

Answer 3

• maximising photosynthesis with controlled factors in a greenhouse
• using fertilisers to help a plant remain fertile
• removing competition and pests
• planting varieties of crops that are pest resistant or produce a higher yield

Question 4

What is intensive farming?

Answer 4

Techniques that aim to produce the maximum food product yield from minimum area of land by:
- using fertilisers and pesticides to aid plant grwoth
- maximising animal growth rates
- minimising labour inputs by using machinery

Question 5

What is organic farming?

Answer 5

Uses more natural, methods of producing crops and rearing animals and avoids the use of artificial chemicals
Yield is generally smaller so products may be more expensive

Question 6

What is sustainable food production?

Answer 6

Producing food in ways that can be continued indefinitely
Example is fish farming

Question 7

What is fish farming?

Answer 7

Fish are a valuable source of protein
Due to overfishing many populations have reduced so international organisations have fishing quotas that provide limits for the number of fish that can be caught in a n area
To allow enough fish to survive and reproduce to maintain their population
Size of fishing nets also must have bigger holes so that smaller, younger fish can escape and only mature full grown fish are caught

Question 8

How can we reduce the use of pesticides and fertilizers?

Answer 8

• Farmers replace soil nutrients by spreading manure
• crop rotation is when different crops are planted each year to maximise plant growth
• biological control is when the natural relationships between pests and predators are exploited by farmers
• Gene technology, developing crops that are more resigantbto pests and diseases

Question 9

What is a hydroponic?

Answer 9

When a plant is grown in water containing dissolved minerals to receive the minerals it needs
Grown in different mediums from soil
Plants grow much quicker

Question 10

What is selective breeding?

Answer 10

When plants and animals are bred for particular characteristics
Plant scientists use it for our growing population
To produce the highest yield, the best plants and animals are chosen to breed with
Crops with high resistant to disease would be used
They could cross the two to get disease resistant and high yielding crops

Question 11

How does a farmer selectively breed?

Answer 11

1) decide which characteristic of the species is desirable
2) select a parent with high levels of this characteristic
3) breed from these individuals
4) select the best offspring and breed again
5) repeat for many generations

Question 12

How has wheat changed from selective breeding?

Answer 12

• had small ears with few seeds, now has large ears with many seeds
• had brittle stalk that’s ears often fall off, now stronger stalks that ears stay on
• ears ripened at different times, now ears ripen at the same time
• stalks grew to different heights, now grow to the same height

Question 13

What are the disadvantages of selective breeding?

Answer 13

• reduces number of alleles of a species, reduces variation so species would go extinct easily
• increases chance of inheriting a genetic disease

Question 14

What is genetic engineering?

Answer 14

A way to alter an organisms genome to produce an organism with desired characteristics as selective breeding is a very long process over many generations

Question 15

What are the benefits of genetic engineering in agriculture?

Answer 15

Cotton - to increase crop yield from the same area of land
Corn - to produce toxins that kill insects
Bacteria - to produce medical drugs such as insulin or drugs to treat animals

Question 16

How is a genetically engineered organism produced?

Answer 16

1) take genes from another organism that codes for this characteristic
2) these are foreign genes
3) they out the forgpeign genes into the plant or animal cells at an early stage of the organisms development
4) as the organism develops it displays the characteristic coded for by the foreign genes

Question 17

What are the risks of genetic engineering?

Answer 17

• eating genetically engineered organisms may less to health problems
• genetically engineered crops may cross pollinate with wild plants and introduce the new gene to wild plants which could disrupt the balance of the ecosystem
• may seem unethical

Question 18

How are organisms genetically engineered?

Answer 18

1) identify gene that codes for desired characteristic
2) remove that gene from the donor organism
3) insert it into the host organism

Question 19

How and why is bacteria genetically engineered?

Answer 19

To produce useful substances like hormones, vaccines and antibiotics
P.g 203 diagram
1) restriction enzymes cut the donor DNA at a specific base sequences and make a staggered cut leaving a few exposed unpaired bases on the end of the DNA strands
2) these are sticky ends
3) the same restriction enzymes are cut open the bacterial plasmid
4) ligase enx
Zymes then rejoin the DNA strands at the sticky ends and the new gene is joined into the plasmid DNA

Question 20

How do scientist check the gene has successfully transferred into the hosts genome?

Answer 20

Add a gene for antibiotic resistance which is a gene marker
1) insert antibiotic resistance gene into the plasmid at the same time as inserting the gene with the desired characteristics
2) transfer the bacteria to a plate containing the selected antibiotic and incubate to allow the bacteria to grow
3) any bacterial colonies will survive because of the marker gene

Question 21

What is biotechnology?

Answer 21

Use of biological processes or living organisms to manufacture products
When a natural predator of pests are added to the environment
Example is GM organisms

Question 22

How are GM organisms created?

Answer 22

When foreign genes are transferred into an organism
Used when referring to plants and animals
golden rice- created when a gene taken from a daffodil is placed into the rice and produces beta-carotene which the body uses to make vitamin A
Bt corn - produced by inserting a gene into maize from the bacteria which codes for a protein that is poisonous to insects pests

Question 23

How do you genetically modify an organism?

Answer 23

Same as genetic engineering but with an extra step
Engineered bacterium or virus carries the modified gene into a plant or animal cell

Question 24

How do you calculate the percentage increase from a graph?

Answer 24

Percentage change = final value - initial value / initial value