Ecology

Question 1

In an ecosystem, what is the difference between a population and a community?

Answer 1

A population is a group of organisms of the same species. A community is a group of populations (different species)

Question 2

What do Plants compete for?

Answer 2

Light, space, minerals, water

Question 3

What do Animals compete for?

Answer 3

Food, territory, mates (within a species only)

Question 4

What name is given to the a) living and b) non-living parts of an ecosystem?

Answer 4

a) biotic b) abiotic

Question 5

What is an ecosystem?

Answer 5

The interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment

Question 6

List the ways in which one organism might depend on another within an ecosystem (interdependence)

Answer 6

Food, shelter, pollination, seed dispersal

Question 7

What are some abiotic factors which might affect a
community of organisms?

Answer 7

light intensity; temperature; moisture levels; soil pH & mineral content; wind intensity & direction; carbon dioxide levels (plants only); oxygen levels (aquatic animals)

Question 8

What are some biotic factors which might affect a
community of organisms?

Answer 8

availability of food; new predators arriving; new pathogens; one species outcompeting another so that there are not enough individuals to breed

Question 9

What is an Adaptation?

Answer 9

Special features an organism has to enable it to be successful within its environment

Question 10

What are the 3 different categories of adaptation which enable an organism to be successful within its environment?

Answer 10

Behavioural, structural, functional

Question 11

What are extremophiles?

Answer 11

Organisms that can live in extreme environments such as high temperature, pressure or salt concentration

Question 12

Where might you find extremophiles in the ocean?

Answer 12

In deep sea vents

Question 13

What are the producers of biomass for all life on earth?

Answer 13

Photosynthetic organisms (including plants)

Question 14

How can we represent feeding relationships within a community?

Answer 14

Food chains or webs

Question 15

What organisms are at the start of all food chains?

Answer 15

Photosynthetic organisms such as plants or algae

Question 16

What is a Quadrat?

Answer 16

A piece of equipment that can be used to estimate percentage cover of plants in an ecosystem

Question 17

What is the Transect Line?

Answer 17

The line along which quadrats can be placed to investigate the distribution of plants within an ecosystem

Question 18

What is meant by the terms ‘distribution’ and ‘abundance’ when studying organisms within an ecosystem

Answer 18

-How the organisms are spread out within the ecosystem
-How many there are

Question 19

In a food chain, name the first trophic level

Answer 19

Producers

Question 20

Name the trophic level in a food chain that feeds on producers

Answer 20

Primary consumers

Question 21

Name the third trophic level in a food chain

Answer 21

Secondary consumers

Question 22

Name the fourth trophic level in a food chain

Answer 22

Tertiary consumers

Question 23

What name is given to a consumer that kills and eats other animals?

Answer 23

A predator

Question 24

What name is given to an animal that is eaten by another animal?

Answer 24

Prey

Question 25

Why do the population numbers of predators and prey rise and fall in cycles?

Answer 25

When prey numbers are high, there is lots of food for the predators, but this means more predators so more prey are eaten.

Question 26

In the carbon cycle, what is the only way in which carbon dioxide can be removed from the air and turned into other carbon compounds?

Answer 26

By plants in photosynthesis

Question 27

In the water cycle, name the process by which water from the ground is returned to the air

Answer 27

Evaporation

Question 28

In the water cycle, name the process by which water vapour is converted to a form that plants and animals can use

Answer 28

Precipitation

Question 29

In the carbon cycle, how is the carbon in dead organisms recycled?

Answer 29

Microorganisms decompose the organism, respire and return carbon dioxide to the air

Question 30

Aside from recycling carbon, what other important role do microorganisms play in decomposition?

Answer 30

Returning mineral ions to the soil

Question 31

(Triple only) Give 3 factors that affect the rate of decay of biological material

Answer 31

Temperature, water availability, oxygen availability

Question 32

(Triple only) What is compost?

Answer 32

Substance produced by decay of waste biological material that can then be used as a natural fertiliser for growing garden plants or crops

Question 33

(Triple only) What is produced by anaerobic decay of waste biological material?

Answer 33

Methane

Question 34

(Triple only) What is biogas?

Answer 34

A fuel containing methane produced by anaerobic decay in biogas generators

Question 35

(Triple only) Give 3 environmental changes that can affect the distribution of species in an ecosystem

Answer 35

Temperature; availability of water; composition of atmospheric gases

Question 36

What is biodiversity?

Answer 36

The variety of all the different species of organisms on earth or within an ecosystem

Question 37

How does high biodiversity make an ecosystem more stable?

Answer 37

By reducing dependence of one species on another for food, shelter

Question 38

What effect are humans having on biodiversity and why is this a problem?

Answer 38

Reducing it; means less available for future use

Question 39

What are the two effects of an increasing human population and increased living standard?

Answer 39

More resources are used; more waste is produced

Question 40

How can pollution occur in water?

Answer 40

Sewage, fertiliser or toxic chemicals

Question 41

How can pollution occur in air?

Answer 41

Smoke and acidic gases

Question 42

How can pollution occur on land?

Answer 42

Landfill and toxic chemicals

Question 43

Why is pollution a problem?

Answer 43

Kills plants and animals and reduces biodiversity

Question 44

Give 4 ways in which humans can reduce the amount of land available for other animals

Answer 44

Building; quarrying; farming; dumping waste

Question 45

Which habitat is being destroyed to produce garden compost?

Answer 45

Peat bogs

Question 46

What two problems are being caused by the destruction of peat bogs?

Answer 46

Reduces biodiversity; burning/decay of peat releases carbon dioxide into the atmosphere which leads to global warming

Question 47

Give two reasons why large scale deforestation is being carried out

Answer 47

To provide land for cattle and rice fields; to grow crops for biofuels

Question 48

Name two greenhouse gases

Answer 48

Carbon dioxide and methane

Question 49

List 3 consequences of global warming

Answer 49

Sea level rise; ice caps melting; habitat destruction; extinction; changes to animal behaviour or distribution

Question 50

What can farmers do to increase biodiversity in fields where they only grow one type of crop?

Answer 50

Reintroduce field margins and hedgerows

Question 51

What can humans do to reduce the amount of waste in landfill?

Answer 51

Recycling resources

Question 52

How can humans help to protect endangered species?

Answer 52

Breeding programmes

Question 53

How can humans help to reduce destruction of rare habitats?

Answer 53

Protection (e.g. laws, nature reserves) and regeneration

Question 54

How can governments help to reduce global warming?

Answer 54

Reduction of deforestation and carbon dioxide emissions

Question 55

(Triple only) What name is given to carnivores with no predators?

Answer 55

Apex predators

Question 56

(Triple only) How do decomposers break down dead plant and organic matter?

Answer 56

They secrete enzymes into the environment. Small soluble molecules then diffuse into the microorganism

Question 57

(Triple only) How can we visually represent the relative amount of biomass in each level of a food chain?

Answer 57

Pyramids of biomass

Question 58

(Triple only) What is represented by each 'bar' on a pyramid of biomass?

Answer 58

The total dry mass of all organisms within a trophic level (average dry mass of one organism x total number of organisms)

Question 59

(Triple only) How is biomass lost between each trophic level in a food chain?

Answer 59

Not all ingested material is absorbed - some egested as faeces; some lost as waste e.g. carbon dioxide and water in respiration; water and urea in urine; glucose used in respiration

Question 60

(Triple only) How do we calculate efficiency of biomass transfers between trophic levels?

Answer 60

% efficiency = biomass available to next level/biomass entering level x 100

Question 61

(Triple only) What is food security?

Answer 61

Having enough food to feed a population

Question 62

(Triple only) What is sustainable food production?

Answer 62

Production of sufficient resources for the population, with minimal impact on the environment and/or leaving enough for the population to recover

Question 63

(Triple only) What are the factors that affect food security?

Answer 63

Increasing birth rate in some countries; changing diets in developed countries; new pests/pathogens; environmental changes e.g. rains fail = famine; cost of agricultural inputs; conflict

Question 64

(Triple only) How does intensive farming increase efficiency of food production?

Answer 64

Restricts energy transfer from food animals to environment

Question 65

(Triple only) Give 2 ways in which energy transfer from food animals to the environment can be reduced in intensive farming

Answer 65

Limiting movement; controlling temperature of surroundings

Question 66

(Triple only) What can be supplemented in animal feed to increase growth?

Answer 66

Protein

Question 67

(Triple only) Why is there currently a need for sustainable fishing methods?

Answer 67

Fish stocks in oceans are declining. If they are too low, breeding cannot continue and species could disappear completely from certain areas

Question 68

(Triple only) Give two ways in which fish stocks can be kept at a sustainable level

Answer 68

Control of net size (smaller nets, larger holes) and introduction of fishing quotas

Question 69

(Triple only) How can genetic modification help meet the food demands of a growing human population?

Answer 69

Genes can be altered to increase crop yield and quality

Question 70

(Triple only) What is mycoprotein?

Answer 70

A protein-rich food produced by Fusarium fungus, suitable for vegetarians

Question 71

(Triple only) Name the fungus that produces mycoprotein

Answer 71

Fusarium

Question 72

(Triple only) What conditions are needed to produce mycoprotein?

Answer 72

Glucose syrup growth medium; aerobic conditions

Question 73

(Triple only) How can scientists grow HUMAN insulin to treat diabetes?

Answer 73

Genetically modified bacteria (alternative is to use animal insulin which is not the same and may have issues for people who object to use of animal products)

Question 74

(Triple only) What is golden rice?

Answer 74

Rice genetically modified to be high in beta-carotene which is needed to make vitamin A