Topic N - Man's use of biological resources

Question 1

How are glasshouses used to increase the yield of certain crops

Answer 1

1. Crops free from pests and diseases
2. Control water supply
3. Artificial light = more time to photosynthesis
4. Trap heat = keep plants warm ( heater used in winter)
5. Increase level of CO2 - use paraffin heater

Question 2

How do polythene tunnels increase crop yield

Answer 2

Large plastic sheet over crops

Keeps crops warm and contains humidity

Question 3

What is the difference between glasshouses and polythene tunnels

Answer 3

Glass houses are more expensive than polythene tunnels because more variables can be controlled

Question 4

How does increasing the temperature and CO2 and light effect crop yield

Answer 4

Increase rate of photosynthesis
Plants grow bigger + faster
Crop yields = higher

Question 5

How does the use of fertiliser increase crop yield

Answer 5

Fertilisers replace missing minerals in the soil or provide more of them= increase crop yield

Question 6

What 4 important minerals do plants require and why

Answer 6

Nitrogen
Phosphorus
Potassium
Magnisum

Because needed to make important compounds like proteins

Question 7

What are the reasons for pest control

Answer 7

To kill pests that feed on crops = fewer plants are damaged or destroyed = increase in crop yield

Question 8

Definition of pesticides

Answer 8

Group of chemicals that target pests

Question 9

Definition of biological control

Answer 9

Alternative to using pesticides

Using other organisms to reduce the number of pests

By encouraging wild organisms or adding new ones ( predators )

Question 10

What are 2 forms of pest control

Answer 10

Pesticides

Biological Control

Question 11

What are the advantages of pesticides

Answer 11

Easy to control
Effective- kills the pest
Relatively cheap

Question 12

What are disadvantages of pesticides

Answer 12

Poisonous to humans
Harm other wildlife
Not very specific
Requires constant labour ( each season )
Can contaminate food supply= effect food chain

Question 13

Advantages of biological control

Answer 13

lasts longer
no reapplication
specific
avoids bioaccumulation ( food chains )
no development of resistance

Question 14

Disadvantages of biological control

Answer 14

New organisms = pest themselves
Undesired/ unknown effects
Less guarantee it will work
Expensive- maintenance + labour ( needs highly trained people )

Question 15

PAPER 2

Why do people want to farm large numbers of fish

Answer 15

To provide protein

Question 16

PAPER 2

What methods are used in fish farming to produce large amounts of fish

Answer 16

1. Maintains water quality ( filter out watste)
2. Protection from interspecific predation ( being eaten by other animals eg. Birds + seals)
3. Controlling intraspecific predation ( organisms eat individuals of the same species) = separate small and large fish so small fish don’t get eaten
4. Controlling quality and frequency of of feeding = maximise energy = bigger + quicker fish will grow
5. Controlling disease
6. Selective breeding = less aggressive + faster growing fish produced

Question 17

what is yeast

Answer 17

a useful microorganism

Question 18

what happens when yeast respires aerobically ( in presence of oxygen)

Answer 18

it breaks down sugar into CO2 and water

Question 19

where is yeast used and how does it work

Answer 19

baking

mixed into the dough to create bubbles of CO2 that make dough rise

Question 20

how does yeast work in the production of bread

Answer 20

1. enzymes breakdown carbohydrates into sugars
2. yeast uses sugars in aerobic respiration = produce CO2
3. when oxygen runs out= anaerobic respiration (fermentation) = produce CO2 + ethanol (alcohol)
4. CO2 produced = trapped in bubbles in the dough
5. pockets of gas expand + dough rises
6. dough baked= temperature kills yeast = stop fermenting + alcohol produced = boiled away
7. yeast dies = bread stop rising – but pockets left in bread where CO2 was trapped

Question 21

what is a fermenter ( in industry) and what are there purposes

Answer 21

a large container where useful microorganism are grown

to make the yield of products from the microorganisms can be as big as possible

Question 22

what is a fermenter filled with

Answer 22

full of liquid culture medium in which microorganisms can grow and reproduce

Question 23

what are the conditions inside a fermenter

Answer 23

conditions are kept at the optimum levels for growth= yield of products can be as big as possible

Question 24

list the conditions controlled in a fermenter

Answer 24

1. aseptic precautions ( sterilisation with superheated steam kills unwanted microbes)
2. nutrients
3. optimum temp + pH
4. oxygenation
5. agitation

Question 25

what are aseptic precautions in a fermenter

Answer 25

vessels sterilised with super heated steam = kill unwanted microbes

Question 26

why are aseptic precautions needed in a fermenter

Answer 26

increases product yield microorganism aren't competing with other organisms product doesn't get contaminated

Question 27

why are nutrients needed in a fermenter

Answer 27

provided in the liquid culture medium needed for growth

Question 28

why is an optimum temp. needed in a fermenter

Answer 28

provided by water cool jacket needed so doesn't get to hot an so enzymes don't denture

Question 29

why is an optimum pH needed in a fermenter

Answer 29

needed for microorganisms enzymes to work efficiently keeps rate of reaction and product yield as high as possible

Question 30

why is an oxygenation needed in a fermenter

Answer 30

provided by pumping in sterile air needed for respiration to provide energy for growth

Question 31

what is agitation in fermenter

Answer 31

when microorganisms are kept in contact with fresh medium by paddles that circulate (agitate) the medium around the vessel

Question 32

why is an agitation needed in a fermenter

Answer 32

needed so microorganisms can always access the nutrients need for growth = increases the product yield

Question 33

what is selective breeding

Answer 33

develops plants and animals with desired characteristics by taking the best plants or animals and breeding them together to get the best possible offspring

Question 34

list some features why organism are selectively bread

Answer 34

maximum yield of meat, milk , grain good health and disease resistant speed, fertility, good mothing skills ( animals ) attractive flowers, nice smells

Question 35

how can plants be genetically modified to improve food production

Answer 35

resistant to insects | resistant to herbicides ( chemicals that kill plants )

Question 36

what are the benefits of making crops insect resistant

Answer 36

farmers don't need to spray as many pesticides = wildlife that doesn't eat crops = not harmed increases crop yield = make more food

Question 37

what are the benefits of making crops herbicide resistant

Answer 37

farmers can spray their crops to kills weeds without affecting crop itself

Question 38

what are the concerns with genetically modifying crops

Answer 38

1. transplanted genes may get out into environment = create super weeds 2. could adversely affect food chains or even human health

Question 39

why are some people totally against genetic engineering all together

Answer 39

worry that changing an organisms genes = create unforeseen problems= passed onto future generations

Question 40

definition of transgenic

Answer 40

transfer of genetic material from one species to a different species genes transferred from another species (eg. insulin- restriction & ligase enzymes, recombinant DNA)

Question 41

PAPER 2 describe the process of micropropagation (tissue culture ) in which explants are grown in vitro ( cloning plants )

Answer 41

1. plant with desirable characteristics is selected to be cloned 2. Explants ( small pieces ) are taken from tips of stem or side shoots = meristem ( stem cells = living growing tissue) 3. explants sterilised= kill any microorganisms 4. explants grown in vitro = placed petri dish containing nutrient medium ( contains nutrients + growth hormones = needed for explants to grow ) 5. cells in explant divide + grow into a small plant (further explants can be taken from small plants until enough are produced) 6. small plants taken out of medium= planted in soil + put in glasshouses 7. develop into plant genetically identical to original plant ( share same characteristics)

Question 42

PAPER 2 what is micropopagation used for

Answer 42

to produce commercial quantities of genetically identical plants with desirable characteristics

Question 43

PAPER 2 describe the stages in the production of cloned mammals ( use dolly the sheep as example )

Answer 43

1. nucleus of sheeps egg cell = removed = enucleated cell ( cell without nucleus ) 2. diploid nucleus from a mature (udder) cell (of a different sheep) = inserted into enucleated cell 3. cell = stimulated ( by electric shock) = start dividing by mitosis ( as if it was a normal fertilised egg) = develops into embryo 4. dividing cell ( embryo ) = implanted in uterus of another sheep ( segregate mother ) to develop until it was ready to be born. 5. result = dolly = clone of sheep that udder cell came from.

Question 44

PAPER 2 how can cloned transgenic animals be used to produce human proteins

Answer 44

cows + sheep make protein naturally in their milk by transferring human genes into the cells of theses animals = produce useful human proteins in milk

Question 45

PAPER 2 what have transgenic chicken been engineered to produce

Answer 45

human proteins in egg white

Question 46

PAPER 2 what can transgenic cows and sheep produce in their milk

Answer 46

can produce human antibodies = used in therapy for illnesses like arthritis, some types of cancer and multiple sclerosis

Question 47

PAPER 2 what can be done to transgenic animals which is beneficial

Answer 47

can be cloned = useful genetic characteristics = passed on ( this doesn't always happen with breeding)

Question 48

PAPER 2 definition of clone

Answer 48

genetically identical organisms