Harnessing biology

Question 1

how does high light intensity create a higher crop yield

Answer 1

more photosynthesis, keeps stomata open

Question 2

how does high CO2 create a higher crop yield

Answer 2

photosynthesis reactant

Question 3

how does warm temperature create a higher crop yield

Answer 3

more kinetic energy for enzymes

Question 4

how does water create a higher crop yield

Answer 4

• reactant for photosynthesis
• transports mineral ions
• transpiration

Question 5

uses of MG in fertiliser

Answer 5

makes chlorophyll

Question 6

uses of NO3 in fertiliser

Answer 6

proteins + DNA

Question 7

uses of PHO3 in fertilisers

Answer 7

DNA

Question 8

uses of K in fertilisers

Answer 8

enzyme reactions

Question 9

What are the advantages of organic fertiliser

Answer 9

• improves soil structure
• greater range of minerals
• releases minerals over a long time
• cheaper

Question 10

What are the disadvantages of organic fertiliser

Answer 10

• slow acting, has to be decomposed
  -bulkier more difficult to apply
• may contain pests

Question 11

What are the advantages of inorganic fertiliser

Answer 11

• mineral ions are released immediately
• contents are known
• easy to apply

Question 12

What are the disadvantages of inorganic fertiliser

Answer 12

• can lead if eutrophication as fertiliser is soluble
• requires regular reapplication

Question 13

What is eutrophication

Answer 13

• Heavy rain leaches minerals from fields
• fertiliser is washed into nearby bodies of water
• high conc of nitrates and minerals caused an algae bloom
• algae bloom covers surface and blocks sunlight
• plants underneath cannot photosynthesise and die
• number of bacteria increase
• dead plants are decomposed by bacteria
• bacteria despiste reducing the oxygen in the water
• low oxygen causes other organisms and animals to die

Question 14

What are the advantages of pesticides

Answer 14

• reduces pest population instantly
• can kill a whole population

Question 15

What are the disadvantages of pesticides

Answer 15

• not specific to the pest
• pest can become resistant
• chemical can affect higher up the food chain

Question 16

What are the advantages of biological controls

Answer 16

• only needed to be introduced once
• pest specific
• pest will not become resistant
• no effect on other animals in the food chain

Question 17

What are the disadvantages of biological control

Answer 17

• takes time to reduce population
• not all population is killed

Question 18

What does the cooling jacket do in a fermenter

Answer 18

Removes heat energy stopping the fermenter from over heating and the enzymes denaturing

Question 19

What does an air filter do in a fermenter

Answer 19

Maintains sterile conditions so no other bacteria is grown

Question 20

What are the purpose of stirrers in a fermenter

Answer 20

Keep the solution from settling and to oxygenate all the parts

Question 21

Explain why temperature must be controlled in a fermenter

Answer 21

So the enzymes are working at their optimum temperature which allows the best growth.

Question 22

What is the bacteria used to make yoghurt

Answer 22

Lactobacillus

Question 23

Describe the stages to make yoghurt

Answer 23

• pasteurise the milk to remove any harmful microorganisms by heating to 95 degrees
• milk is homogenised to dispense fat globules
• cooled to 40 degrees for optimum enzyme activity for lactobacillus
• Lactobacillus respires producing lactic acid
• lactic acid has a low PH and denatures milk proteins causing the yoghurt to thicken
• yoghurt is then cooled to 5 degrees and stirred

Question 24

What are the steps of selective breeding

Answer 24

• Humans select the best individual organisms with the best desirable traits and breed them together
• creates a range of offspring
• select the offspring with the desired trait and repeat process
• repeat for many generations

Question 25

Disadvantages of selective Breeding

Answer 25

• takes a long time
• offspring may not have the desired traits

Question 26

How do farmers feed fish to promote fast growth

Answer 26

High lipid and protein foods
Regular feeding with small amount

Question 27

What is Inter specific competition

Answer 27

Different species compete for food

Question 28

What is intraspecific

Answer 28

Different sized fish will compete for food

Question 29

How do farmers deal with Inter specific and intraspecifc competition

Answer 29

Place different species / sized fish in different ponds

Question 30

How do farmers deal with infectious disease in fish farming

Answer 30

Remove dead or infected fish quickly and remove faeces asaell

Question 31

Definition of biodiversity

Answer 31

The measure of how many different species live in an ecosystem

Question 32

how does deforestation affect the carbon cycle and global warming

Answer 32

• plants are carbon sinks and take in carbon dioxide through photosynthesis
• when trees are cut down the carbon store is released into the atmosphere and the tree is unable to take in CO2 through photosynthesis
• trees may also be burned down which also release CO2 from combustion

Question 33

What are the consequences of carbon minoxide

Answer 33

binds irreversibly with haemoglobin and stops oxygen binding

Question 34

why is sulphur dioxide bad for the environment

Answer 34

sulphur dioxide reacts with atmospheric water vapour to form acid rain
can kill ecosytems and destroy organisms in rivers and lakes

Question 35

how does sewage affect organisms in water bodies

Answer 35

• sewage provides a good source of food for bacteria
• bacteria therfore multiply rapidly
• large population of bacteria respire aerobically using up the oxygen in the water
• decreases the level of oxygen in the water resulting in the death of other organisms as they start respiring anaerobically