5 use of biological resources

Question 1

how can selective breeding develop plants with desired characteristics?

Answer 1

• decrease resistance in food crops
• increase crop yield
• more weather tolerant
• better tasting food

Question 2

how can selective breeding develop animals with desired characteristics?

Answer 2

• needs variation to take place
• use the offspring with the best combination of features
• produced for size

Question 3

negatives of selective breeding in animals:

Answer 3

• reduces genetic diversity
• increased incidence of genetic conditions
• increased vulnerability to disease/ predation/ natural disaster

Question 4

how can glasshouses and polythene tunnels be used increase crop yield?

Answer 4

• increase light
• increase CO2
• increase humidity
• control temp
• monitor pH of soil

Question 5

what does increased carbon dioxide do in glasshouses?

Answer 5

• produced during respiration
• used during photosynthesis
• more CO2= more photosynthesis
• more photosynthesis= higher crop yield

Question 6

what does increased temperature do in glasshouses?

Answer 6

• increases rate of respiration + photosynthesis
• increases rate of growth
• increases enzyme activity

Question 7

how can the use of fertiliser increase crop yield?

Answer 7

• plant food which contains mineral ions for plant growth
• can be organic or inorganic
• extra mineral ions

Question 8

advantages of using biological control:

Answer 8

• more natural
• no resistance formed
• no need to reapply- cheaper
• pest specific

Question 9

disadvantages of using biological control:

Answer 9

• can go wrong- predators start eating crops
• takes a while to reduce population
• not all pests eaten

Question 10

advantages of using pesticides:

Answer 10

• fast acting
• immediate effect
• targets and kills the entire population

Question 11

disadvantages of using pesticides:

Answer 11

• need to reapply
• may kill other species
• toxic to food chain- may cause bioaccumulation

Question 12

role of yeast in the production of food:

Answer 12

• releases carbon dioxide to make bread rise

Question 13

practical: investigate the role of anaerobic respiration by yeast in different conditions:

Answer 13

• effect of temp
• higher temp= faster respiration
• until enzymes denatured

Question 14

role of lactobacillus in yoghurt production?

Answer 14

• bacteria use lactose to respire anaerobically, producing lactic acid, this causes a fall in pH, which denatures proteins and causes them to coagulate

Question 15

what is an industrial fermenter used for?

Answer 15

• to grow micro- organisms on an industrial scale

Question 16

what is the purpose of a cooling jacket on an industrial fermenter?

Answer 16

• keeps enzymes working at optimum temperature
• reduces temperature after respiration heats up contents as respiration produces heat

Question 17

why is it important to maintain aseptic conditions in an industrial fermenter?

Answer 17

• to prevent unwanted micro organisms

Question 18

why is it important to add air and nutrients to the fermenter regularly?

Answer 18

• air- allows oxygen for aerobic respiration
• glucose- for respiration
• amino acids- for growth

Question 19

why is it important to maintain the optimal temperature and pH for the growth of a microorganism in an industrial fermenter?

Answer 19

• so enzymes don’t denature
• measure by electric probe

Question 20

why is it important to stir the contents of an industrial fermenter regularly?

Answer 20

• stops contents from settling to the bottom
• stops condition becoming anaerobic

Question 21

how to promote growth of fish:

Answer 21

• high lipid and high protein food to promote rapid growth
• regular feeding and small amounts- ensure that most gets eaten
• selective breeding to grow desirable fish

Question 22

issues with breeding different fish:

Answer 22

• interspecific competition
• predation

Question 23

what is interspecific competition?

Answer 23

• differed species will compete for food and some species will be wiped out- could place species in different ponds/ tanks

Question 24

what is predation?

Answer 24

• carnivorous species will prey on other fish- could place cover over ponds to reduce predation from birds

Question 25

issues with too many fish in one pond:

Answer 25

• intraspecific competition
• infectious diseases

Question 26

what is infraspecific competition?

Answer 26

• larger fish will outcompete smaller fish for food, large individuals may prey on smaller individuals

Question 27

what are infectious diseases in fish farming?

Answer 27

parasites and pathogens
spread quickly if fish are too close together- could separate fish by age and size, remove dead or infected fish and treat the water with antibiotics to kill the bacteria

Question 28

what is biodiversity

Answer 28

• variety of living organisms in a particular habitat

Question 29

practical: investigate the distribution of organisms in their habitats and measure biodiversity using quadrats:

Answer 29

• quadratic practical

Question 30

effects of deforestation:

Answer 30

• leaching
• soil erosion
• disturbance of evapotranspiration
• disturbance of carbon cycle
• disturbance of the balance of atmospheric gases

Question 31

consequences of polluting water by sewage:

Answer 31

• provides good nutrients of bacteria
• bacteria therefore multiply rapidly
• use up oxygen as they are respiring
• increases biological oxygen demand
• this decreases the overall level of oxygen and kills fish as they cannot respire
• can also lead to eutrophication

Question 32

consequences of carbon monoxide:

Answer 32

• binds with haemoglobin in blood- stops oxygen from binding- can’t transport oxygen so can’t respire

Question 33

consequences of sulphur dioxide:

Answer 33

• dissolves in water to form dilute sulphuric acid and nitric acid
• this rain then has a damaging effect on trees, freshwater and soils
• effects enzymes

Question 34

consequences of leaching from soil:

Answer 34

• causes eutrophication
• this decreases oxygen, kills fish and organisms