ecology

Question 1

abiotic factors

Answer 1

physical features an organisms interacts with in the environment

Question 2

biotic factors

Answer 2

living organisms of the environment that an organism reacts with

Question 3

producer

Answer 3

autotroph; makes its own food, contains chlorophyll which absorbs light energy to convert CO2+H2O into glucose, which stores chemical energy

Question 4

consumer

Answer 4

heterotrophs; organisms that are not able to make their own food, obtaining energy and nutrients by feeding on other organisms

Question 5

primary consumers

Answer 5

organisms that feed on plants only

Question 6

secondary consumers

Answer 6

organisms that feed on primary consumers

Question 7

tertiary consumers

Answer 7

organisms that feed on secondary consumers

Question 8

decomposers

Answer 8

organisms that get their energy by breaking down dead organisms, feces and excretory products; returns nutrients like mineral salts to the environment

Question 9

population

Answer 9

group of organisms of the same species that live together in a habitat

Question 10

community

Answer 10

made up of all the populations of different species living and interacting with one another in a habitat

Question 11

ecosystem

Answer 11

community of organisms interacting with one another and its non-living environment

Question 12

food chains

Answer 12

series of organisms, beginning with producers, through which energy and nutrients are transferred

Question 13

trophic level

Answer 13

the position an organism occupies in a food chain

Question 14

food web

Answer 14

a network of interconnected food chains

Question 15

activity of decomposers

Answer 15

egested and excreted materials, and dead organisms contain trapped chemical energy, which is released
they use some of this energy for their own needs whilst the rest are transferred as heat to environment

Question 16

where does loss of energy go

Answer 16

uneaten body parts, faeces and excretory products

Question 17

ecological pyramids

Answer 17

horizontal bar diagrams where food and energy relationships are shown
producers are at the bottom

Question 18

pyramid of numbers

Answer 18

used to compare number of organisms present in each trophic level at particular time

Question 19

limitations of pyramid of numbers

Answer 19

1. does not compare size/mass of organisms
2. does not compare whether organism is juvenile or adult (developmental stage)

Question 20

pyramid of biomass

Answer 20

used to compare mass of organism present in each trophic level at particular time
constructed based on standing mass (dry mass => when all water has been removed)
biomass of lower tropic level is usually larger than biomass of next trophic level

Question 21

limitations for pyramid of biomass

Answer 21

1. animals have to be killed to obtain biomass
2. have to be constructed at a particular point in time

Question 22

nutrient cycling

Answer 22

when decomposers break down dead organisms, allowing materials locked up inside dead organisms to return back to natural environment to be used again by green plants

Question 23

carbon cycle

Answer 23

where carbon is constantly removed/released to environment in the form of CO2, allows for CO2 concentration to be relatively constant

Question 24

photosynthesis

Answer 24

process where green plants containing chlorophyll convert light energy into chemical energy in the form of carbohydrates (glucose) from carbon dioxide and water

Question 25

feeding

Answer 25

removes CO2 from environment, as animals obtain carbon compounds from feeding on plants/other animals

Question 26

respiration

Answer 26

release of CO2, where food molecules are oxidised to release energy

Question 27

decomposition

Answer 27

release of CO2, where decomposers break down dead organic matter

Question 28

combustion of fossil fuels

Answer 28

release of CO2 into environment

Question 29

importance of carbon cycle

Answer 29

1. ensures continuous supply of CO2 for plants to carry out photosynthesis
2. enables energy to flow through ecosystem (carbon compounds transferred from organism to organism in food chains of an ecosystem)
3. regulates amount of CO2 in atmosphere

Question 30

carbon sink

Answer 30

area that stores carbon from atmosphere for a long period of time and stores more carbon than it releases
removes CO2 from atmosphere

Question 31

oceans as carbon sinks

Answer 31

CO2 dissolves in ocean water absorbed and used by aquatic plants in photosynthesis
portion of carbon compounds are buried in the seabed, in the form of fossil fuels

Question 32

renewable natural resources

Answer 32

air, water, forests, wildlife

Question 32

non-renewable natural resources

Answer 32

fossil fuels (formation takes millions of years, cannot be formed quickly)

Question 33

pollution

Answer 33

process by which harmful substances are added to the environment, making it undesirable or unfit for life

Question 34

pollutants

Answer 34

substances that cause pollution

Question 35

sewage

Answer 35

water-carried waste matter from homes/industries

Question 36

untreated sewage components

Answer 36

phosphates and nitrates (nutrients for algae and water plants => used in the synthesis of proteins and nucleic acids)

Question 37

eutrophication

Answer 37

the increased growth and multiplication of algae and floating water plants in rivers or lakes

Question 38

insecticides

Answer 38

substances used to kill insects

Question 39

bioaccumulation

Answer 39

accumulation of chemical substances such as pesticides in an organism

Question 40

biomagnification

Answer 40

occurs when toxins/insecticides released are passed from one trophic level to the next with increasing concentration along the food chain

Question 41

biodiversity

Answer 41

the range of a species that are present in a particular ecosystem

Question 42

conservation

Answer 42

the protection and preservation of natural resources in the environment