B6.2 - Feeding The Human Race

Question 1

What is food security

Answer 1

Ability for population to have affordable food with sufficient quality and quantity

Question 2

What may threaten food security

Answer 2

• increase in population
• changes in diet: people are becoming more reliant on meat based produce which requires a lot of energy to make than plant products
• climate change: environmental conditions such as lack of moisture in soil, reduces yield of produce.
• new pests and pathogens may evolve

Question 3

What is something good about climate change that benefits crops

Answer 3

With increase of CO2 concentration in atmosphere, this actually helps plants to grow. Through photosynthesis, CO2 is often limiting factor so this reactant helps to maximise rates

Question 4

How to increase food production

Answer 4

• fertilisers: helping land to remain fertile
• maximise photosynthesis: environmental conditions to maximise growth
• remove competition: any pests and pathogens that may kill plant like herbicides
• increase variation of crops: will be able to survive, adapt and reproduce a higher Yield

Question 5

Intensive farming

Answer 5

Attempt to maximise food production by:
- by using fertilisers and pesticides
- maximise animal growth rate
- use machinery and less people
- large scale
- cheaper

Question 6

Organic farming

Answer 6

Natural methods of crop production:- subsistence farming
- no artificial chemicals
- less animals and more time consuming
- done by hand/people
- small scale
- expensive

Question 7

Sustainable food production

Answer 7

Whereby production of food can be continued indefinitely

Question 8

(Advantages) of fish farming

Answer 8

• nets for fishes have big holes. This means only large and matured fish get trapped whereas smaller and young can still move and free to grow and increase in number, allowing not all fish to be caught
• these fishes are also bred together which increases their number and wild fish can recover: stopping extinction of species

Question 9

(Disadvantages) of fish farming

Answer 9

As many fishes are kept very close to each other, possibility of diseases to spread is more frequent and fast.

Question 10

Reducing fertilisers and pesticides

Answer 10

• natural fertilisers such as manure
• crop rotation: timing each crop to grow so soil has a chance to recover and no overgrazing which strips land of nutrients
• using biological control: using natural predators that eat pests and insects

Question 11

Hydrophonics

Answer 11

Process where all plants are grown together with nutrient/ mineral rich water (solute based solutions)

• faster
• sustainable (water is reused and recycled)
• all grown together, same rate
• deliver high yields
• can control pests and diseases

BUT
- expensive
- energy consuming
- require lot of fertilisers

Question 12

Selective breeding

Answer 12

Breeding plants or animals for particular/desired characteristics

Question 13

Process of selective breeding

Answer 13

1. Identity the organism with desired characteristics
2. Choose parent with highest level of desired characteristics
3. Breed from individuals
4. Select best offspring and breed again
5. Repeat for many generations

Question 14

Disadvantages of selective breeding

Answer 14

• all focused towards one particular characteristics, so start becoming all identical and heavily similar.
• this results in reducing variation and decrease in gene pool
• as all clones, if new disease or environment conditions, will not be able to survive, adapt and reproduce and will die out- EXTINCTION
• also increases chances of inheritance diseases

Question 15

Selective breeding vs genetic engineering

Answer 15

• Slower and over many generations / much faster in one gen
• less accurate / very accurate

Question 16

Risks of genetic engineering

Answer 16

• emergences of new allergens
• all become very similar so reduce biodiversity
• crossing between dif breeds with disrupt balance of ecosystem
• seen unethical and fake: think it harms the animals

Question 17

Genetic engineering with bacteria

Answer 17

• identify desired characteristics (e.g. insulin)
• remove from body to extract gene at early stages
• using PCR replicate the gene
• restriction enzyme cuts the DNA to get gene with exposed unpaired bases ‘sticky ends’ which will help to complementary base pair to plasmids
• same restriction enzyme used to cut open the bacterium plasmids
• using ligase enzyme will join together
• the vector + gene marker make a transgenic bacteria
• through UV light or environment conditions (temp and pH) will grow
• as bacteria replicates very quickly will produce high yield of desired characteristic

Question 18

Using antibiotic resistance gene as marker

Answer 18

• follow same process
• when adding desired gene also add gene of antibiotics resistance
• will grow and replicate as normal
• but will know it is successful as the bacteria colonies will survive due to resistance and able to stand environmental conditions- will kill any other genes not supposed to be present

Question 19

Genetic modification

Answer 19

Usually used for plants and animals

Question 20

Examples of GM crops

Answer 20

Golden rice: taking the gene of beta-carotene, which helps the body to make vitamin A
BT corn: taking the gene of bacteria bacillus thuringiensis which codes to protein that is poisonous to pests. As the corn produces this, pests will die trying to feed on it

Question 21

Genetic modification

Answer 21

-similar to GE but instead of using bacteria cells, uses plasmids, viruses and bacteria
- identify the gene for desired characteristics
- take gene from donor organism using restriction enzyme to cut exposed unpaired sticky bass ‘sticky ends’
- using same restriction enzyme, cut DNA of vector ( bacteria, plasmids, virus)
- the useful gene is spliced into DNA and combined DNA added to virus known as insertion
- new host begins to work and replicate as clones

Question 22

Basic idea of GM and GE

Answer 22

Vector (bacteria, plasmid, virus) + gene marker (desired characteristic) = transgenic cell (cell with all)

Question 23

How does GM help food security

Answer 23

• makes the yield larger
• better flavour food
• contains more nutrients
• stop disease and pest from killing plant
• more adapted to environment
• more time efficient