B18- Biodiversity and ecosystems

Question 1

Biodiversity def?
Why is it important?

Answer 1

The variety of different species on Earth or in an ecosystem
Ensures stability of an ecosystem by reducing the dependency on one species for food/shelter

Question 2

2 reasons the population has grown so rapidly

Answer 2

-Healthcare preventing diseases
-Growth of food

Question 3

Deforestation
Why?
Impact?

Answer 3

-Make space for housing, agriculture, quarries and use timber for fuel
-Loss of habitats, lower biodiversity, lower intake of CO2

Question 4

Increased waste
Why?
Impact?

Answer 4

-Increased population, more packaging, more industrial waste from factories
-Air pollution, water pollution

Question 5

Burning fossil fuels
Why?
Impact?

Answer 5

-Generate electricity
-Being used faster than it can be made

Question 6

Peat bog destruction
Why?
Impact?

Answer 6

-Burnt as fuel, in garden compost
-Being destroyed faster than its made, loss of habitats and biodiversity
-Releases carbon dioxide into atmosphere

Question 7

3 causes of land pollution and why are they bad?

Answer 7

Industrial waste- toxic chemicals from factories disposal
Herbicides/ pesticides- toxic chemicals from farming
Household waste- landfill, takes up space, destroys habitats

Question 8

1 cause of air pollution, why is it bad?

Answer 8

Burning fossil fuels- produces smog and acid rain

Question 9

3 causes of water pollution and why are they bad?

Answer 9

Fertilisers in farming, cause eutrophication
Toxic chemicals- from landfill sites, wash into rivers
Untreated sewage- can be pumped into rivers

Question 10

Key reason why pollution is bad?

Answer 10

Can kill organisms and reduce biodiversity

Question 11

2 impurities released from fossil fuels and what do they cause?

Answer 11

Sulfur dioxide- breathing problems, acid rain
Nitrous oxide- acid rain

Question 12

2 Effects of acid rain

Answer 12

-Destroy roots of plants due to lower pH
-Kill leaves of plants from rain

Question 13

Effect of smoke pollution on environment and humans?

Answer 13

-Dimming effect, could cool the Earth temp
-Damage lungs

Question 14

What is smog?

Answer 14

A haze of small particles that can be seen in the air over cities

Question 15

2 ways to monitor pollution

Answer 15

-pH and oxygen measuring instruments
-Bioindicators, species that are only found in certain pH/oxygen levels

Question 16

3 examples of seasonal changes to an environment

Answer 16

Hours of daylight
Amount of rainfall
Temperature

Question 17

3 examples of geographical changes to an environment

Answer 17

Availability of water
Water salt content
Variation in soil pH

Question 18

3 positive & 3 negative examples of human activity changing an environment

Answer 18

Positive: Replanting hedgerows, Conservation measures, Reducing water pollution
Negatives: Pollution from agriculture, Acid rain affecting soil, Climate change

Question 19

4 biological consequences of global warming?

Answer 19

-Loss of habitat- rising sea levels cause flooding
-Change in distribution- changes in temp and rain
-Changes in migration- due to changing seasons
-Reduced biodiversity- extinction

Question 20

2 main greenhouse gases

Answer 20

Carbon dioxide
Methane

Question 21

How do greenhouse gases cause global warming?

Answer 21

Short wavelength radiation from the sun enters the atmosphere and is absorbed by the Earth. Some are re-emitted as longer wavelength radiation into space, but some are absorbed by greenhouse gases in atmosphere. The temp will increase, causing global warming.

Question 22

5 ways humans are reducing the negative effects on biodiversity

Answer 22

Breeding programmes for endangered species
Protection of rare habitats
Replanting hedgerows
Reduction of deforestation
Recycling resources

Question 23

Bioaccumulation explanation?

Answer 23

Toxins enter food chain, hard to break down, build up at each stage, dangerous level of toxins in top predators

Question 24

Eutrophication detailed description

Answer 24

Nitrates and minerals stimulate growth of algae. Creates high competition for light, other plants can’t photosynthesise and die. Increase in microbes to feed on dead plants. Microbes use oxygen to respire. Less oxygen for other organisms, they then die. More microbial respiration. Eventually oxygen levels drop greatly, all aerobic organisms die and the pond is ‘dead’.

Question 25

Trophic levels def?

Answer 25

Positions of organisms within a food chain

Question 26

Trophic levels from 1-4 and their meaning?

Answer 26

1. Producers, make their own food by photosynthesis 2. Primary consumers, herbivores 3. Secondary consumers, carnivores 4. Tertiary consumers, carnivores

Question 27

Apex predator def? Decomposers def?

Answer 27

Carnivores at the top of the food chain with no predators Organisms that break down dead matter into useful nutrients in the soil

Question 28

Biomass def?

Answer 28

The mass of organic matter in living organisms

Question 29

What does a pyramid of biomass look like? Key features?

Answer 29

Producers are always at the bottom The amount of biomass is always less than the previous stage

Question 30

3 reasons why the biomass decreases with each trophic level

Answer 30

-Some used in excretion e.g urea -Some is used in respiration -Non-eaten parts e.g bones

Question 31

Efficiency transfer of biomass equation

Answer 31

Biomass in higher trophic / biomass in lower trophic x 100%

Question 32

What is a pyramid of number?

Answer 32

Number of organisms at each level

Question 33

What is a pyramid of biomass?

Answer 33

The amount of biomass at each trophic level

Question 34

Incident energy def? How much incident energy is used by plants? How much biomass is transferred between each trophic?

Answer 34

The light falling on Earth 1% of incident energy is used by algae and plants for photosynthesis 10% of biomass from a trophic level is transferred to the level above

Question 35

Food security def?

Answer 35

Having enough food to feed a population

Question 36

6 biological factors that are affecting food security

Answer 36

-Increasing birth rates -Changing diets in developed countries, local food transported away from people who need it -New pests and pathogens in farming -Environmental changes, flooding/droughts -Cost of agricultural inputs, seed, fertilisers -Conflicts

Question 37

3 ways to create sustainable food production

Answer 37

-Maintaining soil quality -Finding more efficient methods -Taking care of fish stocks

Question 38

How can growth in livestock be increased? Why can this be bad?

Answer 38

By feeding the livestock a high-protein diet It adds an extra step to the food chain so less biomass and food is at the end of the chain

Question 39

2 ways to improve the efficiency of food production (farming)

Answer 39

-Limiting the movement of animals to reduce respiration -Controlling the temperature to reduce respiration, less energy transfer to the environment, more biomass for growth

Question 40

Why are fish stocks concerning?

Answer 40

Fish stocks in the ocean are declining, if breeding can't take place then a species may disappear

Question 41

2 ways to help maintain fish stocks and what do they mean?

Answer 41

Controlling net size, allow baby fish to escape and later breed Quotas, allowed number of fish to catch

Question 42

Why is modern biotechnology helpful?

Answer 42

It allows large quantities of microorganisms to be cultured for food

Question 43

What could genetically modified bacteria be used to produce? What could genetically modified crops be used to provide?

Answer 43

Drugs such as insulin on an industrial scale, helps people with diabetes More food/ food with improved nutritional value e.g golden rice

Question 44

Name of the new protein-rich food developed recently? Made from? How is it created? Why is it good?

Answer 44

Mycoprotein Fusarium fungus which grows on glucose syrup Grown in aerobic conditions, then harvested and purified Cheap ingredients, reproduces rapidly