BY5 - Ecology

Question 0

Define autotroph

Answer 0

An organism that obtains organic food molecules without eating other organisms. Autotrophs use energy from the sun or from the oxidation of inorganic substances to make organic molecules.

Question 1

Define the term abiotic

Answer 1

A factor which makes up the non-biological environment

Question 2

Define biodiversity

Answer 2

An expression of the number of different species living in a given ecosystem

Question 3

Define biomass

Answer 3

The dry mass of organic matter composed of a group of organisms in a particular habitat

Question 4

Define biotic

Answer 4

An ecological factor that makes up part of the living environment

Question 5

Define the term ecosystem

Answer 5

A natural unit of living components (biotic) in a given area as well as all the nonliving (abiotic) factors they interact with e.g. Desert, arctic, forest

Question 6

Define the term population

Answer 6

A group of organisms of the same species living in the same area at the same time e.g. population of bluebells in deciduous wood

Question 7

Define the term ecology

Answer 7

The study of interrelationships between organisms and their environment

Question 8

Define the term community

Answer 8

Populations of different species that occupy a particular area e.g. woodland community (flowers, insects, mice etc)

Question 9

Define the term habitat

Answer 9

A particular area occupied by a population

Question 10

Define the term microhabitat

Answer 10

Small localities within habitats with its own characteristics within a larger habitat

Question 11

Define the term niche

Answer 11

An organism’s role in an ecosystem including all of its interactions within a community and its environment

Question 12

What is a food web?

Answer 12

A food web shows the energy flows within an ecosystem, in any food web there will be several trophic levels

Question 13

Define the term nutrition

Answer 13

It is the process by which living organisms obtain energy to maintain life functions and matter to create and maintain structure

Question 14

What is a detritivore?

Answer 14

They are holozoic organisms that feed off detritus e.g. woodlice and dungbeatles

Question 15

What are saprobionts (decomposers)?

Answer 15

Are microbes such as bacteria or fungi that obtain nutrients from dead organisms extracellular digestion

Question 16

Define the term trophic efficiency

Answer 16

The percentage of energy at one trophic level that is incorporated into the next trophic level

Question 17

Define the term gross ecological efficiency

Answer 17

The rate at which energy is passed from one trophic level to another. This varies from one ecosystem to another

Question 18

Why is a large proportion of light energy not absorbed?

Answer 18

They are the wrong wavelength

Is reflected or transmitted

Question 19

In plants what happens to the light energy absorbed?

Answer 19

Used up during photosynthesis and transpiration
Are incorporated into organic plant products (e.g: glucose)
Used up in respiration

Question 20

Define photosynthetic efficiency

Answer 20

A measure of the ability of a plant to absorb light energy. It depends on external factors such as light intensity and temperature.

Question 21

Define biological productivity

Answer 21

The rate at which biomass accumulates in an ecosystem

Question 22

Define primary productivity

Answer 22

The production of new organic matter by green plants

Question 23

Define secondary productivity

Answer 23

The production of new organic matter by consumers

Question 24

Give the equation for primary productivity

Answer 24

NPP = GPP - respiration

Question 25

Define conversion efficiency

Answer 25

The quantity of material taken in and incorporated in biomass

Question 26

Give the advantages of using a pyramid of energy

Answer 26

Takes into account rate of production and shows energy transfer per unit time No inverted pyramids Can compare ecosystems

Question 27

Give the disadvantages of a pyramid of energy

Answer 27

Obtaining data to construct them is complex and difficult | Energy is lost at each trophic level and heat through respiration

Question 28

Define succession

Answer 28

New organisms replace existing ones as abiotic factors alters the conmunity

Question 29

Define primary succession

Answer 29

Introduction of plants and animals into areas that have not previously supported a community (bare rock)

Question 30

Define secondary succession

Answer 30

Reintroduction of organisms into a bare habitat previously occupied by plants and animals

Question 31

What is the term used to describe the different stages in succession?

Answer 31

Sere

Question 32

What is the stable stage in succession?

Answer 32

Climax community

Question 33

What colonises bare rock?

Answer 33

Pioneer species (lichen, mosses)

Question 34

Give two factors that aid the colonisation of a habitat

Answer 34

Seeds and spores may survive and remain in the soil and begin to germinate Migrating animals defecate which decomposes improving the nutrient content of the soil

Question 35

Give the six ways humans interfere in the development of a climax community

Answer 35

``` Grazing Moorland management Farming Deforestation Industry Urban development ```

Question 36

Define conservation

Answer 36

The planned preservation of wildlife

Question 37

List the factors that can lead to extinction

Answer 37

``` Overhunting Competition from introduced species Deforestation Pollution Drainage of wetland ```

Question 38

Give seven conservation techniques

Answer 38

Reintroduction programmes: red kite in mid Wales Protection and breeding programmes for endangered species UK nature Conservancy Council Eco-tourism: responsible travel minimising impact on the environment Gene Banks: sperm and seed banks Rare breed societies Legislation and international corporation to restrict trading of endangered species (CITES) and global organisations (WWF) to increase public awareness

Question 39

Why is the conservation of existing gene pools is important

Answer 39

For ethical reasons – we have a stewardship role to help other species survive Plant species are an important human assets: they are a source of food, medicines, chemicals and disease resistant genes

Question 40

Give four examples of agricultural exploitation

Answer 40

Removal of hedgerows to make larger fields Monoculture Use of chemicals by farmers (herbicides, pesticides, inorganic fertilisers) Damage to bog habitats

Question 41

What do fertilisers contain

Answer 41

Nitrates and phosphates

Question 42

Why do crops need fertilisers

Answer 42

Harvesting removes these minerals, elements and interrupts natural recycling of nutrients

Question 43

Give three ways high nitrate levels in waterways can be overcome

Answer 43

Restrict the amount of fertiliser applied to the soil Only apply fertiliser when crops are actively growing Leave a strip of land 10 m wide next to watercourses

Question 44

Briefly outline eutrophication

Answer 44

Leeching of fertilisers Algae grow Plants are shaded Plants and algae die Dead algae and plants decomposed by micro Microbes multiply and use up the dissolved oxygen in water Dissolves oxygen levels decreases Aquatic animals die because their biochemical oxygen demand are not met

Question 45

Define deforestation

Answer 45

The removal of trees in an unsustainable way

Question 46

Give five reasons for deforestation

Answer 46

``` Demand for timber as building material Wood used for charcoal To clear land for farming To improve transport infrastructure by building new roads To make paper and cardboard packaging ```

Question 47

What are the consequences of deforestation

Answer 47

Climate change: if trees are cut down less CO2 is removed from the atmosphere by photosynthesis Destruction of natural habitats: reduces biodiversity and potential loss of plant species that are potential source of new medicines Soil erosion,: digging and ploughing loosens soil increasing erosion; removal of trees on higher slopes can lead to low land flooding after heavy rainfall; removal of vegetation affects regional climates by also reducing the rainfall leading to desertification

Question 48

Define forest management

Answer 48

The sustainable replanting and regeneration of forests

Question 49

What are the techniques employed in managed forestry

Answer 49

Coppicing Selective cutting Long rotation times

Question 50

How can forestry efficiency be improved

Answer 50

Planting trees optimum distances apart so they grow thicker and have less competition for sunlight Remove only high-quality timber sorts of fewer trees are felled Control pest and disease so higher quality timber is grown

Question 51

Define overfishing

Answer 51

Unsustainable fishing, the rate of removal exceeds the rate at which they reproduce due to measured intensity and efficiency of farming methods

Question 52

Give an effect of overfishing on other wildlife

Answer 52

Predators have no food as overfishing decreases the fish population which are their prey

Question 53

Give the controls that can be used to reduce the impact of overfishing

Answer 53

Impose fishing quotas Restrict mesh size of nets International corporation limiting the size of catches allow fish stocks to be preserved to support marine ecosystems Enforcement of closed seasons for fishing Enforcement of exclusion zones Legislate size of fishing fleets and number of days at sea Encourage fishing of non-traditional varieties Discard young fish that are caught Consumer pressure to buy ethically sourced fish

Question 54

What is fishfarming or aquaculture

Answer 54

Used for species such as salmon and trout. Fish are bred and grown to maturity in ponds/lakes/estuaries in managed enclosures

Question 55

Give the problems associated with fish farming

Answer 55

Very dense stocks lead to disease that can spread to wild fish Antibiotics are used to keep the fish healthy Pesticides are used to control marine parasites also harm marine invertebrates Fertilisers are used to increase phytoplankton for feeding Waste from excretion, fertiliser and waste food can need to eutrophication Farmed fish could interbreed with wild fish and weakeb stocks

Question 56

Give two main reasons of increased atmospheric carbon dioxide levels

Answer 56

Deforestation and burning of fossil fuels

Question 57

Give examples of greenhouse gases

Answer 57

Carbon dioxide Methane Chlorofluorocarbons Nitrogen dioxide

Question 58

How do greenhouse gases contribute to climate change

Answer 58

They form an insulating layer in the atmosphere | They only allow light through but prevent heat from escaping into the atmosphere

Question 59

Give examples of climate change

Answer 59

``` Polar ice caps melting Rise in sea levels Changes in rainfall patterns More droughts, hurricanes and forest fires Increased crop yields and pest numbers ```

Question 60

Give three sources of biofuels

Answer 60

Wood Biogas (methane, ethanol) Biodiesel (corn, sugarcane, rapeseed)

Question 61

Net primary productivity

Answer 61

The energy in an ecosystem available to consumers

Question 62

Detritus

Answer 62

Dead organic matter

Question 63

Primary productivity

Answer 63

The production of new organic matter by green producers

Question 64

Secondary productivity

Answer 64

The production of new organic matter by consumers