Food Production

Question 1

Use of glasshouses

Answer 1

-provide farmers with an enclosed environment which they can control the climate of and increase crop yields

Question 2

How are conditions of the glasshouse are manipulated

Answer 2

-additional lighting (winter months)
-burn fuels - higher temp and CO2 and water vapour
-Hydroponics for balance of minerals
-transparent material allows sunlight in for photosynthesis (greenhouse effect)

Question 3

How does burning fuels increase crop yield

Answer 3

-CO2 (more photosynthesis)
-water vapour (less transportation so plant does not wilt)
-temperature (enzyme activity)

Question 4

Protein denature

Question 5

How does the greenhouse effect keep the greenhouse warm

Answer 5

-shortwave radiation enters then reflects off contents of greenhouse
-they reflect off as long wave radiation which cannot pass through glass, so stays in the glasshouse and becomes warmer

Question 6

What are polythene tunnels/polytunnels

Answer 6

-large plastic tunnels that cover crops
-protect crops from effects of weather
-increase temperature in the tunnel
-prevent entry of pests that can damage plants or diseases

Question 7

What are fertilisers

Answer 7

-increase the amount of key nutrients in the soil for crop plants
-grow larger and healthy

Question 8

What are pesticides

Answer 8

-Chemicals kill off unwanted insects and weed species
-less damage done to crop plants by insects
-less competition from other plant species, increasing yield

Question 9

Organic fertilisers examples

Answer 9

-farmyard manure and compost

Question 10

Forms of chemical fertilisers

Answer 10

-applied to the soil as dry granules
-sprayed on in liquid form

Question 11

Use of nitrates and its deficiency in plants

Answer 11

-needed to make amino acids
-weak growth and yellow leaves

Question 12

Use and deficiency of phosphorus (phosphates) in plants

Answer 12

-needed to make DNA and cell membranes
-poor root growth and discoloured leaves`

Question 13

Potassium use in plants and its deficiency

Answer 13

-needed for enzymes in respiration and photosynthesis
-poor growth of flower and fruits, brown spots on leaves

Question 14

Types of pesticides

Answer 14

-insecticides
-herbicides
-fungicides

Question 15

How do pests, weeds and fungi affect plant crowth

Answer 15

-pests: eat crops and damage them
-weeds: outcompete crop plants for space, water and soil nutrients
-fungi: infect crop plants and spread disease that affects growth and yield

Question 16

Advantages of pesticides

Answer 16

-accessible and cheap
-immediate effect
-increase crop yield and quality
-can kill entire population of pests

Question 17

Disadvantages of using pesticides

Answer 17

-organisms can develop resistance
-non specific chemical and can kill beneficial organisms (like bees)
-can lead to bioaccumulation
-need to be repeatedly applied

Question 18

Biological control

Answer 18

Using a natural predator to eat pest species

Question 19

Advantages of biological control

Answer 19

-avoids bioaccumulation
-no resistance
-can target specific species
-long lasting
-does not need to be reapplied

Question 20

disadvantages of biological control

Answer 20

-may eat other organisms instead of the pest
-takes a longer period of time to be effective
-cannot kill the entire population
-may become a pest itself
-may eat other organisms instead of the pest

Question 21

fermentation

Answer 21

using respiration carried out by microorganisms to make a useful product

Question 22

how is beer made

Answer 22

-made from barley
-barley is mashed and put into hot water to activate enzymes (starch to maltose)
-yeast added to mixture
-maltose from barley is fermented by yeast

Question 23

how is bread made

Answer 23

-wheat flour and water are mixed together, then yeast is added
-enzymes from cereal grain in the flour break down starch to form sugars
-yeast respires using sugars
-initially yest respires aerobically
-when air runs out, yeast respires anaerobically and produce more CO2 and ethanol
-CO2 produced is trapped in small air pockets which later rise
-when the dough is baked in the oven, the gas bubbles expand
-baking kills yeast and evaporates the ethanol

Question 24

anaerobic respiration of lactobacillus in milk

Answer 24

lactose -> lactic acid

Question 25

what does the lactic acid do in yoghurt

Answer 25

-lactic acid released by the bacteria causes physical and chemical changes in the milk to make yoghurt -the acid denatures the milk protein, causing it to coagulate -it also makes the milk taste sour -the acidity also prevents other microorganisms from growing in the yoghurt, acts as a preservative

Question 26

how is yoghurt made

Answer 26

-equipment is sterilised to kill other bacteria and prevent chemical contamination -milk is pasteurised at 85-95C to kill other bacteria -milk is cooled to 40-45C and lactobacillus bacteria is added -mixture is incubated at this temp for hours, lactobacillus digest milk proteins and ferment the sugar in milk -lactobacillus converts lactose into lactic acid and increases acidity sours and thickens the milk in the yoghurt -yoghurt is stirred and cooled to5C to halt action of the lactobacillus

Question 27

why is the milk pasteurised and equipment pasteurised in when making yoghurt

Answer 27

-less production, spoil taste -other bacteria no killed would compete and use lactose in the milk

Question 28

what are industrial fermenters

Answer 28

-containers used to grow microorganisms like bacteria and fungi in large amounts -conditions can be carefully controlled to produce large quantities of the microorganisms

Question 29

useful products that can be made in fermenters

Answer 29

-insulin -antibiotics -hormones -yeast

Question 30

components of an industrial fermenter

Answer 30

-paddle stirrers -gas outlet -water jacket, place to add and remove water -probes -equipment to analyse probe -tap -air inlet with filter -nutrient input -microbe input/tap in

Question 31

purpose of the paddle stirers

Answer 31

-distribute food nutrients -distribute oxygen -distribute heat/even out temp

Question 32

purpose of gas outlet

Answer 32

-ensures pressure does not build up, CO2 can be collected and sold to fizzy drinks companies

Question 33

purpose of water jacket

Answer 33

-ensure temp remains constant -promotes optimum enzyme activity and prevents denaturing of enzymes in microbes

Question 34

purpose of the probes and the analyser

Answer 34

-these continuously detect the internal conditions within the fermenter, analyser analyses information from probes and adjusts the setting and inputs to maintain optimum conditions -pH, temp, oxygen levels

Question 35

purpose of air inlet

Answer 35

supply organisms that respire aerobically with sterile air

Question 36

nutrient input

Answer 36

provides microbes with energy source and growth materials they require

Question 37

how are fermenters kept clean

Answer 37

-steam to clean it to kill microorganisms and prevent chemical contamination, ensures only desired microbes will grow

Question 38

why is fish farming needed

Answer 38

-most fish are caught in the wilds, overfishing has lead to declines in many fish populations -fish farms raise large numbers of fish in a small space to provide food (protein) for humans

Question 39

advantages of fish farming over wild caught fish

Answer 39

-fish types: can select species that produce bigger fish and carry out selective breeding -easy to catch, can catch all year round, produces large numbers -reduce overfishing, no food chain disruption, sustainable yield -less risk to fishermen

Question 40

methods in fish farms to ensure high yields

Answer 40

-control intraspecific predation and overcrowding (separated by size and age) -control interspecific predation (separated by tanks) -control disease an infection (kept ion small numbers) -antibiotics and remove dead fish -biological control of pests -control oxygen -remove waste products (faeces and sewage) -frequent feeding ion small amounts (no overeating) -high protein diet -selective breeding (fish with desired characteristics to reproduce) -hormones? -maintain high water quality