TOPIC 5

Question 1

Advantages of GM crops over pesticides

Answer 1

1) doesn’t bioaccumulate, unlike pesticides/ enter other food chains
2) targets specific insects/ areas
3) reduces the need for pesticides
4) doesn’t require reapplication
5) pesticides can lead to health problems
6) insects can become resistant to pesticides

Question 2

ADVANTAGES of pesticides over GM CROPS

Answer 2

1)Pesticides kill quickly, ar more rapidly effective than GM crops
2) insects can become resistant to GM crops
3) some customers may not buy GM crops
4) farmers can become dependants on GM CROP PATENTS for their seeds
5) GM pollen may kill insect pollinators
6) GM plants can cause cross-pollination

Question 3

NITROGEN:

Answer 3

-needed to make amino acids in plants
-lack: causes weak growth and yellowing of the leaves

Question 4

PHOSPHOROUS

Answer 4

-needed to make DNA and cell membranes
-lack: poor root growth and discoloured leaves

Question 5

POTASSIUM

Answer 5

-allows ENZYME REACTIONS to take place in respiration and photosynthesis
-lack: can cause poor flower/ fruit growth + brown spots

Question 6

Inorganic fertilisers

Answer 6

-carefully curated chemical compounds of minerals, nitrogen, phosphates and potassium
-are used in the form of sprays or pellets

Question 7

Organic fertilisers

Answer 7

-manure or compost

Question 8

Advantages and disadvantages of fertilisers

Answer 8

Organic= sustainable, but ineffective
Chemical = can cause eutrophication, and damage insects and wildlife, effective

Question 9

GREENHOUSES: lighting

Answer 9

Artificial lighting- can remove the light lost during the nighttime + winter seasons
Thin + clear walls also maximise sunlight that reaches plants

Question 10

GREENHOUSE: temperature

Answer 10

Artificial heating: can provide warmth necessary for the optimum enzyme reaction rate
“Greenhouse effect”, also means that heat is trapped in the greenhouse and naturally warms the inside

Question 11

GREENHOUSE: CO2

Answer 11

-artificial heaters burning fuel will also release CO2, which helps plants photosynthesize quicker

Question 12

GREENHOUSES: water

Answer 12

-ARTIFICIAL HEATERS: also release water vapour which reduces the water loss during transpiration
-Water can also be managed and monitored carefully

Question 13

GREENHOUSES: protection

Answer 13

-greenhouses also protect the crops from external wind and storm and pests

Question 14

Describe the process of yoghurt production:

Answer 14

1) all equipment is sterilised to kill any unwanted bacteria
2) milk is pasteurised at a high temperature (85) to kill any unwanted bacteria/microorganisms and prevent competition
3) milk is then cooled to around 40 degrees where the LACTOBACILLUS + STREPTOCOCCUS starter cultures are added
4) lactobacillus digests the proteins in the milk to convert lactose into lactic acid, which lowers the pH- causing the milk to thicken (environment prevents growth of microorganisms)
5) the thickened yoghurt is then cooled down to 5 degrees and stirred
6)fruit and flavourings can now be added

Question 15

Describe the process of bread production

Answer 15

1) yeast is added to dough of (flour, water, wheat) and kept at a warm temperature, to allow the yeast enzymes to work at it’s optimum temperature
2) the yeast break down the flour to use it’s sugars to respire, and aerobically respire to produce co2 packets of gas in the bread, making it rise
3) when it cannot anymore, it anaerobically respires, producing ethanol and co2,
4) when the dough has finished proving, it should be around 4 to 5 x it’s initial volume as the dough has risen
3) the hot temperatures in the oven when baking eventually kill the yeast + evaporates any ethanol produced from anaerobic respiration

Question 16

What are fermenters used for and why

Answer 16

Fermenters are large, industrial-sized fermenters used to grow ‘culture’ microorganisms in large amounts
-the advantage is that you can maintain and control all conditions to maximise the microorganism production

Question 17

Describe the structure of a fermenter

Answer 17

1) STERILISED: hot steam is pumped through at a high pressure
2)microorganism ‘culture’ and nutrients are added to the container
3) stirring paddles AGITATE the contents, and keep it flowing and moving, ensuring even distribution
4) water jackets cover the outside to keep it cool and control the temperature of the container
5) air inlets low oxygen to be pumped in for aerobic respiration
6) temperature and ph probes detect and regulate levels

Question 18

PRACTICAL: investigating the rate of anaerobic respiration in yeast (6)

Answer 18

C- change the type of yeast (live or dead) or (type of sugar/ temperature/conc. of sugar etc.)
O- same species of yeast
R- repeat the practical 5 times
M- measure the time taken for change in indicator to occur OR measure the number of bubbles produced in a fixed time
M- use a timer and a counter
S- control the temperature of room, oxygen level of water, oxygen entering solution, type of sugar added, same person, same indicator, control pH + concentration of solution, mass of yeast added
S- boil off water to boil off any oxygen dissolved in water, use hydrogen carbonate (orange to yellow), add a layer of oil on top to prevent oxygen from entering solution

Question 19

Describe the process of GENETIC MODIFICATION:

Answer 19

1) the TARGET GENE is isolated and located in the original organism
2) is then cut by RESTRICTION ENZYMES, which leave the DNA with ‘sticky ends’
3) a bacterial PLASMID is isolated from the bacterium cell
3) the SAME restriction enzymes are then used to cut the bacterial plasmid, leaving it with COMPLEMENTARY ‘sticky ends’, which ensure that the DNA and the plasmid will ‘stick’ together
4) the enzyme, LIGASE, joins the plasmid and isolated gene to create the recombinant plasmid
5)which is inserted into a bacterial cell

Question 20

How is INSULIN produced:

Answer 20

1) the human INSULIN gene is located and isolated, then cut by the RSTRICTION ENZYMES, leaving it with ‘sticky ends’
2) a bacterial PLASMID is isolated from the bacterium cell
2) the SAME restriction enzymes then cut the plasmid, leaving it with COMPLEMETNARY ‘sticky ends’ that will match and stick to the DNA
3) LIGASE enzyme joins the DNA and PLASMID together to from the RECOMBINANT PLASMID
4) this is inserted into a bacterial cell, which reproduces rapidly, copying the recombinant plasmid, quickly spreading the HUMAN INSULIN GENE which will be expressed by all new bacteria
5) the genetically engineered bacteria is then placed in a FERMENTER to reproduce quickly under controlled conditions

Question 21

DEFINE TRANSGENIC

Answer 21

The transfer of genetic material from one species to another species

Question 22

How are bacteria and viruses VECTORS:

Answer 22

they act as a means of transferring a gene

Question 23

How can GM CROPS benefit food production

Answer 23

1) they can be modified to produce poisons that kill insects and pests- improve crop yields
2)they can be modified to have additional nutrients, health benefits, colour etc- golden rice, added vitamin A
3)modified to be insect/herbicide resistant- so herbicides will only kill weeds not the crop
4)modified to be drought resistant

Question 24

DISADVANTAGES of GM crops:

Answer 24

1) GM crops have not been researched enough to know it;s long lasting effects
2) inserted genes can be transferred to wild plants and cancel out the resistance to weeds
3) increased costs of seeds, mean that smaller, poorer farms are outcompeted by larger farms
4) increased dependancy on herbicides
5) reduced biodiversity where herbicides are used

Question 25

DEFINE selective breeding

Answer 25

When organisms with desirable characteristics are selected and then bred together -repeated for many successive generations until a ‘new breed’ reliably shows the characteristics

Question 26

Why are selectively bred:

Answer 26

PLANTS: -drought resistant -more fruitful/colourful -better tasting -disease resistant -large flowers ANIMALS: -gentler/friendlier personality in domestic animals -coloured furs/ patterns in fur -chickens that lay larger eggs -produces more milk or meat -sheep with better wool -horses with faster pace

Question 27

Problems with selective breeding:

Answer 27

-inbreeding (increases chance of genetic defects and vulnerability to new diseases)

Question 28

ADVANTAGES of FISH FARMING

Answer 28

1) ability to control water quality 2) produces large quantities of fish in a small area 3) ability to control predation + feeding 4) ability to selectively breed fish

Question 29

What is carefully monitored and controlled in fish farming?

Answer 29

1) intra + interspecific predation 2) water quality 3) feeding quality + frequency 4) control + removal or waste products 5) control of diseases 6) the use of selective breeding

Question 30

How is WATER QUALITY controlled in FISH FARMING?

Answer 30

-pH, oxygen levels, salinity of water are constantly monitored by sensors + regulated -water is cleaned to remove harmful bacteria that can cause infections -oxygen can be pumped into water to provide sufficient levels of oxygen, that dissolve in the water, for respiration

Question 31

INTRA vs INTERspecific predation definition + control

Answer 31

INTRA: within one species -fish are kept apart from age and size to prevent bigger fish from eating younger, smaller fish INTER: between other species -fish of different species ar kept separated by fences, nets and tanks

Question 32

Control of DISEASE in fish farming

Answer 32

1) dead waste + faeces must be removed to prevent bacterial infections developing and spreading in the water 2) ANTIBIOTICS are given to fish in their feeding 3) kept in small numbers to minimize risk of spreading disease

Question 33

SELECTIVE BREEDING in FISH FARMING

Answer 33

-fish are separated by gender to allow the farmer to only allow the fish with desired characteristics to reproduce

Question 34

Control of FEEDING QUALITY + FREQUENCY in FISH FARMING

Answer 34

-fish are fed small pellets- made of smaller fish- packed with protein and nutrients to ensure fast growth -pellets so often have antibiotics to prevent disease -fed frequently but in small amounts - prevents overfeeding but also prevents fish from eating each their

Question 35

MICROPROPOGATION

Answer 35

1) cells are scraped from the parent plant- called the EXPLANT 2) explant is sterilised with disinfectant and rinsed in distilled water 3) placed in a growth medium (Petri dish with nutrient sterile agar), nutrients encourage cells to divide by mitosis and grow into a bundle of cells called a CALLUS 4) CALLUS is transferred to a new growth medium, with plant growth regulators (hormones) that encourage CALLUS to grow shoots, roots and leaves and turn into a PLANTELET 5) PLANTLET can then be transferred to a potting tray to grow into a plant

Question 36

ADVANTANGES of micropropogation

Answer 36

1) species that are infertile (e.g many strains of banana) can still be reproduced in large quantities 2) large quantities can be stored easily + produced rapidly 3) plants can be produced at any time of the year 4) genetic modification can be introduced into thousands of new plants rapidly

Question 37

Disadvantages of micropropagation

Answer 37

-requires trained personnel + laboratory -as all plants are identical, all are vulnerable to the same diseases/pests

Question 38

CLONING process (embryonic cloning)

Answer 38

1) egg cells from the female are removed and artificially INSEMINATED with sperm cells from the male 2) the newly formed embryo is then split apart many times before the cells of the embryo can specialise- creating genetically identical seperate embryos 3)these clone embryos are TRANSPLANTED into host mothers 4) the offspring birthed are genetically identical

Question 39

CLONING process (adult body cell method)

Answer 39

1) take an egg cells from a donor, and remove it’s nucleus- forming an ENUCLEATED cell 2) take a body cell from the parent, and insert it’s nucleus into the enucleated egg cell 3) using a small, electric shock to fuse the nucleus and cell together and stimulate the egg cell to begin mitosis 4) the egg cell then divides and splits, eventually forming an embryo 5) the embryo can be inserted into the womb of a surrogate mother 6) the offspring birthed is genetically identical to the parent of the body cell

Question 40

How can cloning animals make human proteins in medicine?

Answer 40

The TRANSGENIC animal, is bred to contain a foreign gene which codes for a useful human protein, causing the animal to produce this protein and therefore secrete it into their milk -the animal can then be cloned to create a herd or flock of animals that all create the special milk Process is known as PHARMING EXAMPLE: alpha-1-antitrypsin- used to treat cystic fibrosis