Ecology

Question 1

What is ecology?

Answer 1

The interaction of organisms with each other and with their environment

Question 2

What are biotic factors and examples of them?

Answer 2

Biotic factors are the living components of an ecosystem, for example
Predators
Pathogens
One species outcompeting another
Availability of food

Question 3

What are abiotic factors and examples of them?

Answer 3

Abiotic factors are the nonliving components of an ecosystem, for example
Light intensity
Temperature
Moisture levels
Soil pH and mineral levels
Wind intensity
Carbon dioxide levels
Oxygen levels

Question 4

How do plants compete with each other for resources?

Answer 4

By bigger plants having bigger leaves to absorb more light and longer roots to absorb more minerals and water

Question 5

What resources do animals compete for?

Answer 5

Water, food, territory and mates

Question 6

Define interdependence

Answer 6

Each species depending on other species in a community for things such as food, shelter, pollination etc

Question 7

Why will a smaller organism struggle to keep warm?

Answer 7

A smaller organism will have a larger surface area to volume ratio which causes them to lose heat more easily and struggle to keep warm

Question 8

Why does a larger organism retain heat better?

Answer 8

A larger organism will have a smaller surface area to volume ratio which means they don’t lose heat as easily and can keep warm

Question 9

What are structural adaptations and give an example

Answer 9

Features of an organism’s body structure such as shape and colour e.g. an arctic animal having white fur to blend in

Question 10

What are behavioural adaptations and give examples

Answer 10

The way organisms behave e.g. species of birds migrating to warmer climates in the winter or owls being nocturnal

Question 11

What are functional adaptations and give examples

Answer 11

The things that go on inside the organism’s body that can be related to processes like reproduction and metabolism e.g. bears lowering their metabolism when hibernating or desert animals producing little sweat and only small amounts of concentrated urine

Question 12

What are extremophiles?

Answer 12

Microorganisms that are adapted to live in very extreme environments, for example
Volcanic vents
Very salty lakes
High ocean pressures

Question 13

What do trophic levels show?

Answer 13

How many steps away the organism is from the start of the chain

Question 14

What is a pyramid of biomass?

Answer 14

A chart, drawn to scale, showing the biomass at each trophic level - it’s the total mass of all the organisms of one trophic level

Question 15

Why is biomass lost at each stage?

Answer 15

Uneaten materials e.g. bones
Waste products e.g. faeces, urine, carbon dioxide
Used in metabolic reactions e.g. respiration

Question 16

How do you calculate biomass?

Answer 16

Efficiency = biomass transferred to next level / biomass available at previous level x 100

Question 17

What is the carbon cycle?

Answer 17

The processes and events involved in recycling carbon through the environment

Question 18

What is the process of the carbon cycle?

Answer 18

1) Carbon is taken out of the air in photosynthesis - glucose is a carbon based compound
2) Carbon moves through food chains as plants and animals are eaten and the carbon becomes part of their fats and proteins which are also carbon based compounds
3) Carbon is then returned to the atmosphere when animals respire, as dead animals decay, in burning fossil fuels by humans and dissolved in oceans

Question 19

What are examples of decomposers?

Answer 19

Bacteria and fungi

Question 20

What are examples of detritivores / detritus feeders?

Answer 20

Beetles, slugs, snails, woodlice, maggots, earthworms

Question 21

How do decomposers break down dead matter?

Answer 21

By a process called decay / rotting
They do this by releasing enzymes to the dead matter and consuming the broken down substance

Question 22

How do detritus feeders breakdown dead matter?

Answer 22

They feed on detritus (organic matter made up of dead plants or animals) and digest it internally. They can also feed on faeces

Question 23

What is decay?

Answer 23

The breakdown of dead organic matter (often called rotting)

Question 24

What four factors affect the rate of decay?

Answer 24

Temperature
If the temperature is too high or too low then the decomposing enzymes can’t survive and the rate of decay is slowed down
Oxygen levels
If there is a lack of oxygen, the decomposing enzymes can’t respire and survive, slowing down the rate of decay
Water levels
If there is a lack of water, the decomposing enzymes can’t survive, slowing down the rate of decay
The number of decay organisms
If there are less organisms to produce decomposing enzymes to feed on the dead matter, the rate of decay will be slower

Question 25

How do decomposers and detritus feeders contribute to the carbon cycle?

Answer 25

Decomposers and detritus feeders feed on dead matter and the waste of animals. They respire and release carbon dioxide into the atmosphere. The dead matter not consumed is turned into fossil fuels

Question 26

What are biofuels and how do they differ from fossil fuels?

Answer 26

Biofuels are fuels made from recently living organisms. They are different from fossil fuels because those organisms died millions of years ago

Question 27

What are the positives of biofuels?

Answer 27

They are cheap, renewable and easy to transport Biofuels are also carbon neutral because they only release carbon dioxide that the organism had taken in during its lifetime

Question 28

What are the negatives of biofuels?

Answer 28

They require a lot of space (deforestation is often needed to make the fields) and transportation, harvesting and processing releases carbon dioxide

Question 29

How do batch generators work?

Answer 29

They are manually loaded with waste, left to digest and then the products are cleared away

Question 30

What are the positives and negatives of batch generators?

Answer 30

Positives They don’t have to be filled up as often as continuous generators Negatives They don’t produce biogas at a steady rate They only produce biogas in small batches

Question 31

How do continuous generators work?

Answer 31

Waste is continually fed in so the biogas is produced at a steady rate

Question 32

What are the positives and negatives of continuous generators?

Answer 32

Positives They produce biogas at a steady rate They are suitable for large scale projects Negatives They have to be filled up very often

Question 33

Why has population explosion occurred?

Answer 33

Medical advancements and improved agricultural productivity

Question 34

Why is Africa experiencing greater population growth than other parts of the world?

Answer 34

High fertility rates, declining mortality rates and improved healthcare

Question 35

Why is the mass of household waste increasing each year?

Answer 35

The growing population An increase in the standard of living e.g. more disposable packaging and overbuying resources

Question 36

What is the process of the greenhouse effect?

Answer 36

1) Energy from the sun is absorbed by the Earth 2) The Earth radiated this energy back out into the atmosphere 3) The greenhouse gases in the atmosphere absorb the energy 4) The gases re-radiate the energy in all directions, including back down to Earth

Question 37

What are the causes of global warming?

Answer 37

Burning fossil fuels Deforestation (fewer trees to take in carbon dioxide in photosynthesis and the trees are also often burned or left to decompose which releases carbon dioxide)

Question 38

What are the consequences of global warming?

Answer 38

Rising sea levels due to the melting ice caps and glaciers that run into the sea Changes in the distribution of organisms e.g. organisms that need warmer climates may be spread further Changes in migration patterns causing animals to migrate at different times of the year Extreme weather such as floods, droughts, heatwaves, forest fires, hurricanes and cyclones Reduced biodiversity

Question 39

What is algal bloom and how does it affect wildlife?

Answer 39

When fertilisers wash into rivers, allowing algae to grow but this blocks the light for plants in the water and causes them to die. This means that there is a lack of photosynthesis to produce oxygen for the fish in the water and they also die

Question 40

How is soil erosion caused and how can it lead to the collapse of food webs?

Answer 40

It’s caused by toxic chemicals used in farming polluting the soil (it can also be caused by nuclear waste buried underground). This results in reduced mineral concentration in the soil, leading to less plants being able to survive and less food being available to species as the producers at the bottom of the food chain have been reduced

Question 41

How is acid rain formed and how can it harm biodiversity?

Answer 41

Burned fossil fuels release sulphur dioxide which reacts with rain, creating acid rain. This damages plants and makes lakes acidic, massively affecting biodiversity as it reduces photosynthesis which reduces the availability of food and it hugely affects marine life

Question 42

What are the four main human activities that reduce the amount of land available to plants and animals?

Answer 42

Building Farming Quarrying Dumping waste

Question 43

What are the main reasons for deforestation?

Answer 43

Provide land for farming and quarrying Provide land and wood for building Provide fuel and paper

Question 44

What are the effects of deforestation?

Answer 44

Increased carbon dioxide concentration Increased global warming Loss of habitats due to soil erosion

Question 45

What are the effects of destroying peat bogs?

Answer 45

Reduction of biodiversity Loss of habitats Carbon dioxide is released when burned which contributes to global warming

Question 46

What is food security?

Answer 46

Having enough food to feed a given population

Question 47

What factors can threaten food security?

Answer 47

Drought War / conflict Natural disasters Disease in crops Economic crisis Cost of agricultural machinery Population growth Changing diet in developing countries

Question 48

How can farmers increase the growth of animals?

Answer 48

Feeding animals a more protein concentrated diet Factory farming livestock (raising them in small pens), fish can be factory farmed in small cages Keeping them in temperature controlled conditions (this reduces the amount of energy used for keeping warm / movement so that more energy is available for growth)

Question 49

What are the advantages of battery farming?

Answer 49

More efficient Costs less Less labour intensive Less risk of attack from predators like foxes Less energy is lost from the food chain so there is more available for human consumption

Question 50

What are the disadvantages of battery farming?

Answer 50

Horrible conditions for the animals Unethical Animal cruelty Diseases can spread among the animals easily Energy used to control temperatures comes from burning fossil fuels Quality of the product is poorer

Question 51

What are the consequences of overfishing?

Answer 51

It reduces the amount of fish available for human consumption, it affects food webs and has led to some species becoming endangered

Question 52

How can fish stocks be sustained?

Answer 52

Having fishing quotas (limits on what fish can be caught) Having bigger holes in nets so baby fish can escape Limiting fishing during breeding season so that populations can recover

Question 53

What is mycoprotein?

Answer 53

Mycoprotein is a new food source, used to make a high protein, low fat meat substitute from fungi

Question 54

How is mycoprotein made?

Answer 54

It is made from Fusarium which is grown in large vats on glucose syrup which acts as food and oxygen is supplied so the fungus can respire aerobically. Nitrogen (in the form of ammonia) and other minerals are also supplied. It’s kept at 30 degrees celsius and the optimum pH. The fungal mass is then harvested, purified and dried to make the mycoprotein

Question 55

How can cultured meat slow down the rate of global warming?

Answer 55

Less farming of cows that release methane Less fossil fuels burned for farming facilities (heating, transport etc) Less deforestation because less space is needed

Question 56

What are other advantages of cultured meat, aside from slowing down the rate of global warming?

Answer 56

It can be mass produced It’s disease free meat There’s no harm to animals so there are less ethical issues and it could be suitable for vegetarians More land would then be available for farming crops

Question 57

How can loss of biodiversity be reduced?

Answer 57

Breeding programmes for endangered species Protection of habitats Reintroduction of hedgerows (the bushes on the side of the roads) Reduction of deforestation and carbon dioxide emissions Recycle rather than dump waste