Use of Biological Resources

Question 1

How can glasshouses and polythene tunnels be used to increase the yield of certain crops?

Answer 1

Conditions such as temperature, carbon dioxide and light can be controlled so that there are no rate-limiting factor. This ensures a maximum yield.

Question 2

What are the effects of increasing carbon dioxide and temperature in glass houses?

Answer 2

• Increasing amount of CO2 increases crop yield as there is more reactant= more product
• increasing the temperature increases crop yield as enzymes are at optimum temperature so the rate of photosynthesis increases.
• more photosynthesis= more glucose = more energy for growth= higher yield.

Question 3

Why are fertilisers used to increase crop yield?

Answer 3

They contain minerals that plants require (e.g. NKP)
Nitrates= amino acids–> proteins–> growth
Phosphates= needed for respiration and growth as cells need phosphorus to make DNA and cell membranes.
Potassium= enzymes need potassium for respiration and photosynthesis.

Question 4

What are the reasons for pest control and biological control?

Answer 4

Pests can eat/damage crops so they cannot be sold= less profit for farmers.

Question 5

Advantages of pest control?

Answer 5

Ensures crop yield is maximum
Doesn’t damage the actual crop
Fast and accurate
Instant results

Question 6

Disadvantages of pest control

Answer 6

Can harm other wildlife
Killing pests may affect diversity
Pests can become immune
Can leech into soils and pollute surrounding rivers and habitats.

Question 7

What are the positives of biological control

Answer 7

Cheap
No harm to other species 
Self regulating 
Lasts longer 
Specific
No resistance 
No effect on food chains

Question 8

What are the disadvantages of biological control

Answer 8

May effect biodiversity or enter wildlife

Question 9

What is the role of yeast in beer production?

Answer 9

Yeast is required as it converts sugar to ethanol and carbon dioxide when it respires anaerobically.

Question 10

Describe an experiment to investigate carbon dioxide production by yeast in different conditions

Answer 10

1) place yeast in a glucose solution in a test tube and add a layer of oil on top to prevent yeast from respiring aerobically.
2) place test tube in water baths of different temperatures
3) collect gas coming off in a gas syringe and compare depending on temperature.

Question 11

Role of lactobacillus in yoghurt production

Answer 11

When lactobacillus bulgaricus respires anaerobically, it produces lactic acid, which denatures the protein and cusses it clump together= yoghurt

Question 12

Why are aseptic precautions required in a fermenter

Answer 12

Needed to prevent the entry of microbes that would use up the nutrients and O2, effect the production and contaminate it.

Question 13

Need for nutrients in fermentor?

Answer 13

To allow rapid growth of cells

Question 14

Need for optimum ph and temperature in fermentor

Answer 14

Helps enzymes work at their best ability.

Question 15

Need for oxygenation in fermenters

Answer 15

Allows aerobic respiration to occur

Question 16

Need of Agitation in fermentor

Answer 16

Paddle wheels agitate and spread out the reactants so that they are not concentrated in one area.

Question 17

What methods are used to farm large numbers of fish to provide a source of protein?

Answer 17

Water quality: water is filtered:gets rid of waste (e.g. faces and leftover food) –> avoids pollution.
Intraspecific: fish separated by age and gender, regularly fed and given adequate room.
Interspecific: fish in tanks and also nets.
Disease: water is changed, surroundings sterilised and small amounts of fish kept together.
Quality and frequency of feeding: fed in small amounts with nutrient rich food.
Selective breeding: fish with strong characteristic are bred together.

Question 18

How can plants and animals with desired characteristics be made?

Answer 18

Selective breeding.

Question 19

Use of restriction enzymes

Answer 19

Used to cut DNA at specific sites

Question 20

Ligase enzymes

Answer 20

Used to join or stick DNAs together.

Question 21

What cam plasmids and viruses act as and how

Answer 21

Vectors

They take up pieces of DNA and inset this recombinant DNA into other cells.

Question 22

What does recombinant mean?

Answer 22

When DNA fragments are inserted into a vector

Question 23

How can large amounts of human insulin be produced?

Answer 23

From GM bacteria
The insulin causing gene is taken from a cell using a restriction enzyme and is the placed into a bacteria’s DNA. Bacteria is then put into a fermentor where conditions are optimum for it to replicate many times= a lot of insulin.

Question 24

Potential for producing GM plants to improve food production

Answer 24

• Increases plant resistance to infectious diseases caused by fungi, bacteria and viruses
• increases plant resistance to pests
• give plants immunity to chemical herbicides

Question 25

What does transgenic mean

Answer 25

The transfer of genetic material from one spices to a different specie.

Question 26

Describe process of micropropagation .

Answer 26

• A number of explants are removed from the parent plant ate are sterilised using a disinfectant solution and rinsed with distilled water.
• place the explant in vitro contain agar.
• cell division by mitosis creates a mass of cells called a Callus and this is placed into a fresh growth medium containing a mixture of plant growth regulators.
• light, water and humidity are all controlled.

Question 27

What is micropropagation used for

Answer 27

For the production of commercial quantities of clones with desirable characteristics.

Question 28

Stages in animal cloning e.g dolly the sheep

Answer 28

A nucleus with its diploid set of chromosomes are removed from an adult body cell
This is inserted into an enucleated cell
The cell is given an electric shock to trigger cell division by mitosis and form an embryo
Embryo is placed in the womb of a surrogate mother
Offspring is produced, identical to the organism that had its nucleus removed.

Question 29

Potential for using cloned transgenic animals for human antibodies

Answer 29

Animals can be used to make human antibodies which are them infected Into the person.
This is an advantage as the person does not have to wait for their body to produce antibodies

Question 30

Potential for using cloned transgenic animals for organ transplants

Answer 30

No shortage
No rejection
No problems with relatives

Question 31

Advantages of animal cloning

Answer 31

Infertile animals can be cloned
Can happen at any time of the year
Desired traits can be passed on.

Question 32

Disadvantages of animal cloning

Answer 32

Cloned animals may develop problems
Cloning is new technology, consequences that we don’t know of
Low success rate
Expensive and time consuming