Use of Biological Resources

Question 1

How can greenhouses and polyethene tunnels increase crop yield?

Answer 1

The conditions are kept at the optimum for growth, including the use of artificial lighting and trapping heat from the sun

Question 2

How does increased temp increase the crop yield?

Answer 2

-Enzymes work more efficiently at higher temperatures and reaction rates are faster
-Enzymes are involved in key growth processes and photosynthesis

Question 3

How does a continuous supply of carbon dioxide increase the crop yield?

Answer 3

-Co2 is needed for photosynthesis which is needed to provide energy for growth
-Without a constant supply for enough CO2, it may become a limiting factor and so the rate of photosynthesis is slower

Question 4

How do fertilisers increase crop yield?

Answer 4

Fertilisers provide nutrients for the plant which are needed for growth to make crops large and give a plentiful yield

Question 5

State 2 methods of pest control

Answer 5

-Biological control
-Pesticides

Question 6

What is biological control?

Answer 6

A method of controlling plant pests by deliberately introducing organisms that feed on the pests to decrease the number of them

Question 7

Give 2 advantages of pesticides

Answer 7

-Cheap
-Easy to use

Question 8

3 disadvantages of pesticides

Answer 8

-They are not specific so it can kill other insects that are not pests
-They can contaminate water sources
-They have to be applied more than once.

Question 9

Give 3 uses of yeast

Answer 9

-Fermentation of alcohol
-Baking
-Making biofuels

Question 10

How does yeast cause bread to rise?

Answer 10

The yeast breaks down the sugars in the bread in respiration and produces carbon dioxide which causes the bread to rise

Question 11

Describe how yoghurt is made from milk

Answer 11

-Lactobacillus is used to break the lactose in milk into lactic acid
-Lactic acid lowers the pH of the milk which causes proteins to denature and makes milk into yoghurt.

Question 12

What is fermenter used for?

Answer 12

To produce large cultures of microorganisms

Question 13

State 5 things that need to be controlled in an industrial fermenter

Answer 13

-Temperature
-pH
-Nutrient levels
-Oxygen levels
-Contamination

Question 14

Write in order the parts of a fermenter

Answer 14

-Gases out
-Nutrients in
-Mixing blades
-Water jacket for temperature control
-Products out

Question 15

Give 6 methods used in fish farming to increase yield

Answer 15

-Ensuring good water quality
-Controlling predation
-Controlling disease
-Clearing wast
-Managing feeding
-Selective breeding

Question 16

How is water quality mantained in fishing areas?

Answer 16

-Waste removed
-Pathogens killed

Question 17

What is the difference between intraspecific and interspecific predation, in terms of fish?

Answer 17

Interspecific predation-Where other species eat the fish
Intraspecific predation→Where fish eat one another

Question 18

Describe how selective breeding is carried out

Answer 18

-Organisms with the desired traits are selected
-These organisms are bred together
-This process is repeated until the offspring have the desired characteristics

Question 19

What genetic engineering?

Answer 19

Altering the genome of an organism

Question 20

How are new genes introduced into an organism

Answer 20

-The organism’s genes are cut using restriction enzymes to create sticky ends
-The DNA from a bacterium is also cut to produce sticky ends
-The gene is inserted into the bacterium and joined together by DNA ligase enzymes

Question 21

3 benefits of genetically modified crops

Answer 21

-The plants are resistant to herbicides and disease
-Grow bigger and quicker
-They can grow in harsher environments and without the need to continue to top up nutrients frequently

Question 22

What is a transgenic organism?

Answer 22

An organism that contains foreign DNA

Question 23

Describe the process of tissue culture

Answer 23

-Small cuttings (explants) are taken from the plant that you wish to clone
-The cuttings are placed in an agar dish containing growth hormones
-Once the new plants have grown enough, they are transferred to soil

Question 24

2 benefits of tissue culture (micropropagation)

Answer 24

-Can produce many plants quickly
-Can produce lots of plants with desirable traits

Question 25

Describe how animal cell cloning can be carried out

Answer 25

-The nucleus is removed from an unfertilised egg cell to create an enucleated cell
-The nucleus is removed from a cell from the animal you wish to clone
-The nucleus is placed in the enucleated cell and cell division is triggered by an electric shock
-Once the embryo gets big enough, it is placed in a surrogate mother

Question 26

Give one example of a human protein made by a transgenic organism

Answer 26

Insulin (modified E.Coli)