biological resources for food production ✓

Question 1

how can glasshouses be used to increase the yield of certain crops ?

Answer 1

glasshouses contain the main factors affecting photosynthesis at the best amounts to increase the yield of the crops

Question 2

how can polythene tunnels be used to increase the yield of certain crops ?

Answer 2

the structures warm up the soil and protect the crops from frosts which makes more plants be able to be grown

Question 3

what are the effects on crop yield of increased carbon dioxide ?

Answer 3

more carbon dioxide means more photosynthesis

Question 4

what are the effects on crop yield of increased temperature ?

Answer 4

higher temperature increases the rate of photosynthesis by increasing the enzyme activity

Question 5

how can fertiliser increase crop yield ?

Answer 5

they contain NPK
Nitrogen - for the growth of leaves and stems
Phosphorous - for healthy roots
Potassium - for healthy leaves and flowers
(Mg - needed to make chlorophyl)

Question 6

what are the reasons for pest control ?

Answer 6

to get rid of organisms that are reducing the amount of yield of crops

Question 7

what are the advantages of using a pesticide ?

Answer 7

kill the organisms quickly to quickly increase the yield of crops being made

Question 8

what are the disadvantages of using a pesticide ?

Answer 8

• can kill all organisms not just the pests
• can enter food chains and kill other organisms or destroy the food source which disrupts food chains
• can contaminate food products with chemicals that could be harmful

Question 9

what are the advantages of using biological control ?

Answer 9

• only targets pest species and not beneficial insects

- reduces the need to use pesticides

Question 10

what are the disadvantages of using biological control ?

Answer 10

adding new organisms can cause problems to other organisms

Question 11

what are the types of pesticides ?

Answer 11

insecticide - kills insects
fungicide - kills fungi
herbicide - kills weeds

Question 12

what is the role of yeast in the production of bread ?

Answer 12

• yeast respires and releases carbon dioxide
• the bubbles get trapped in the dough and make it rise
• when the bread is baked the yeast are killed

Question 13

what is the role of yeast in the production of beer ?

Answer 13

• yeast feeds on sugars in fruit or in grain

- it respires anaerobically to make ethanol this is fermentation

Question 14

what is an experiment to see the role of anaerobic respiring yeast in different temperatures ?

Answer 14

• mix sugar, yeast and distilled water and add mixture to test tube
• attach a bung with a tube leading to second test tube of water
• sealing the two test tubes with bungs stops oxygen from getting in
• place tube with yeast mixture in a water bath at certain temperature
• leave the tube to warm up and then start counting how many bubbles are produced in a given amount of time
• calculate rate of CO2 production by number of bubbles ÷ time taken shows respiration rate
• repeat at different temperatures

Question 15

what is the role of the bacteria lactobacillus in the production of yogurt ?

Answer 15

• yogurt is made from milk
• the bacteria lactobacillus is added to the milk
• it feeds on the lactose sugar
• it respires anaerobically
• lactic acid lowers the PH and denatures the protein in the milk
• the protein becomes insoluble and thickens the milk

Question 16

what is yeast ?

Answer 16

yeast = single celled fungus

Question 17

how does yeast respire ?

Answer 17

aerobically or anaerobically

Question 18

what is the symbol equation for aerobic respiration ?

Answer 18

C6 H10 6O2 → 6COs + 6H2O

Question 19

what is the word equation for anaerobic respiration ?

Answer 19

glucose → carbon dioxide + ethanol

Question 20

what is the use of an industrial fermenter ?

Answer 20

• can produce lots of microorganisms quickly
• industrial fermenters are kept at the optimum levels for growth which means the yield of products from the microorganisms can be as big as possible