Use of biological resources

Question 1

How can greenhouse and polythene tunnels increase crop yield

Answer 1

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

Question 2

how does increased temperature increase crop yield

Answer 2

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

Question 3

How does a continuous supply of CO² increase crop yield

Answer 3

• CO² needed for photosynthesis which is needed to provide energy foe growth
• without constant supply, it may become limiting factors, so rate of photosynthesis is slower

Question 4

How to fertilizers increase crop yield

Answer 4

• fertilizers provide nutrients to plant
• needed for growth
• makes crops large and give plentiful yield

Question 5

2 methods of pest control

Answer 5

• biological control
• pesticides

Question 6

Define biological control

Answer 6

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

Question 7

2 advantages of pesticides

Answer 7

• cheap
• Easy to use

Question 8

3 disadvantages of pesticides

Answer 8

• not specific, cab kill other insects that are not pests
• can contamination water sources
• have to be applied more than once

Question 9

3 uses of yeast

Answer 9

• fermentation of alcohol
• baking (makes bread rise)
• making biofuels

Question 10

How does yeast cause bread rise

Answer 10

• yeast breaks down sugars in the bread in respiration
• produces CO² which causes bread to rise

Question 11

Describe how yogurt is made feom milk

Answer 11

• bacteria (lactobacillus) used to break lactose in milk down into lactic acid
• lactic acid lowers pH of milk
• causes protein to denatured and makes milk turn into yoghurt

Question 12

What is a fermenter used for

Answer 12

to produce large cultures of microorganisms

Question 13

5 things that need to be controlled in an industrial fermenter

Answer 13

• temperature
• pH
• nutrients levels
• oxygen levels
• contamination

Question 14

What is genetic engineering

Answer 14

altering the genome of an organism

Question 15

How are new genes introduced into an organism

Answer 15

• organisms genes are cut using restriction enzymes to create sticky ends
• DNA from a bacterium is also cut to produce sticky ends
• gene is inserted into the bacterium and joined together by DNA ligate enzymes

Question 16

3 benefits of genetically modified crops

Answer 16

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

Question 17

Define a transgenic organism

Answer 17

an organism that contains foreign DNA