B18 - Biodiversity and Ecosystems

Question 1

What is biodiversity?

Answer 1

Variety of all different species of organisms on earth, or within an ecosystem

Question 2

Why is biodiversity important?

Answer 2

• Ensures stability of ecosystems by reducing dependence on one species on another for food

Question 3

Why are we producing more waste?

Answer 3

• Rapid growth in human population
• Increase in standard of living
• All leads to more resources being used and more waste

Question 4

What are examples of pollution?

Answer 4

• Water=sewage, fertiliser or toxic chemicals
• Air=smoke and acidic gases
• Land=landfill or toxic chemicals

Question 5

How have humans reduced the amount of land available for other animals and plants?

Answer 5

• Building
• Quarrying
• Farming
• Dumping waste

Question 6

What problems do destroying peat bogs cause?

Answer 6

• Reduces the area of habitat and reduces the variety of different plants, animals and microorganisms that live there
• Decay or burning of peat releases carbon dioxide into atmosphere

Question 7

Why has deforestation occured in tropical areas?

Answer 7

• Provide land for cattle and rice fields
• Grow crops for biofuels

Question 8

What are the problems of deforestation?

Answer 8

• Loss of biodiversity
• Releases carbon dioxide into atmosphere
• Reduces rate carbon dioxide is removed from atmosphere

Question 9

What are the consequences of global warming?

Answer 9

• Melting of polar ice caps
• Rise in sea level could threaten cities
• Weather patterns more unusual weather
• Animals migrate to poles to find habitats with suitable temperatures
• Tropical diseases become more common
• Extinction of species - reduced biodiversity

Question 10

What is contributing to global warming?

Answer 10

Increasing levels of carbon dioxide and methane

Question 11

What reduces biodiversity?

Answer 11

• Increase in human population and waste produced
• Deforestation
• Peat bog destruction
• Global warming

Question 12

What is conservation?

Answer 12

Preservation of ecosystems and organisms that live within them

Question 13

How can we reduce the negative effect of humans on biodiversity?(5)

Answer 13

• Breeding programmes to preserve endangered species
• Protection and development of rare habitats
• Reintroduction of hedgerows as there is higher biodiversity in them than field they surround
• Reducing deforestation and release of greenhouse gases
• Recycling instead of dumping waste in landfill sites

Question 14

What are trophic levels?

Answer 14

Different stages in a food chain or web

Question 15

What is trophic level 1?

Answer 15

Plants and algae that make their own food

Question 16

What is trophic level 2?

Answer 16

Herbivores that eat plants/algae

Question 17

What is trophic level 3?

Answer 17

Carnivores that eat herbivores

Question 18

What is trophic level 4?

Answer 18

Carnivores that eat other carnivores

Question 19

What percentage of light is transferred from light to plants?

Answer 19

1%

Question 20

What do decomposers do?

Answer 20

Break down dead plant and animal matter by secreting enzymes into environment and then small soluble food molecules diffuse into microorganism

Question 21

What are pyramids of biomass constructed for?

Answer 21

• Represent relative amount of biomass in each level of a food chain

Question 22

How do you construct a pyramid of biomass?

Answer 22

• Trophic level 1 at the bottom

Question 23

What percentage of biomass is transferred from one level to the next?

Answer 23

10%

Question 24

Why is biomass lost between each trophic level?

Answer 24

• Not all ingested material is absorbed, some egested as faeces
• Some absorbed material is lost as waste, e.g carbon dioxide and water in respiration and water and urea in urine

Question 25

How do you find efficiency of biomass transfers?

Answer 25

Percentage efficiency transfer=biomass in higher trophic level/biomass in lower trophic level * 100

Question 26

What is food security?

Answer 26

- Measure of the availability of food required to support people of a household, region or country

Question 27

How is food security reduced?

Answer 27

- Increase in human population - Changing diets mean sarce food resources are transported to be sold to other areas from areas which need them - New pests and pathogens attack crops and farm animals - Effects of climate change - farming more difficult(famine in some countries) - Increased costs of farming - Armed conflicts affecting how available food is

Question 28

How can efficiency of food production be improved?

Answer 28

- Restricting energy transfer from food animals to the environment - Limiting their movement and controlling temperature of surroundings

Question 29

What is intensive farming?

Answer 29

- Using machines, natural and artifical fertilisers and high-yield crops to maximise the amount of food produced - e.g removing hedgerows from fields to make them bigger and easier to farm - e.g keeping livestock in smaller pens with regulated temperatures

Question 30

What are advantages of intensive farming?

Answer 30

- Higher yields - More efficient use of land

Question 31

What are the disadvantages of intensive farming?

Answer 31

- Ethical objections to some modern methods - Can increase risk of antibiotic resistance

Question 32

What is organic farming?

Answer 32

- No machines to same extent as intensive - No artificial pesticides to crops and use natural fertilisers like compost and manure - Rotate their crops to avoid monoculture - Organic is often more expensive as it has a lower yield

Question 33

Why is important to protect fish stocks?

Answer 33

- Declining - Some fish are at risk of disappearing in some areas

Question 34

How can we conserve fish stocks?

Answer 34

- Control of net size - Introduction of fishing quotas(limit amount of fish that can be caught and killed from specific species)

Question 35

What do sustainable fisheries not do?

Answer 35

- Do not reduce overall number of sih - Number of fish that are caught and killed does not ever exceed the birth of new fish

Question 36

What is biotechnology?

Answer 36

- Alteration of living organisms to make products that help us - examples are cloning and genetic modification - helps us meet the food demands of our increasing population

Question 37

What is genetic modification?

Answer 37

- Genes can be removed using enzymes and inserted into genome of other individuals in same species - e.g bacteria to have human gene for insulin

Question 38

What is the funguc Fusarium useful for?

Answer 38

Producing myoprotein - protein rich food suitable for vegetarians