Life on earth

Question 1

abiotic factors

Answer 1

non-living factors present in an ecosystem such as temperature, soil moisture, light intensity and pH

Question 2

abundance

Answer 2

the quantity of species in an area

Question 3

acclimatise

Answer 3

adjust or become accustomed to new surroundings- for example when using a choice chamber it is important to allow time for the organism to acclimatise before recording results

Question 4

adaptation

Answer 4

is an inherited characteristic (physical, physiological r behavioural) of an organism which enables it to survive successfully in its habitat

Question 5

advantageous mutation

Answer 5

a random change to an organism’s genetic material that is beneficial and increases the organism’s chance of success

Question 6

algal bloom

Answer 6

rapid growth of algae (simple, aquatic plants) in water

Question 7

allege

Answer 7

each of two or more alternative forms of a gene that arise by mutation

Question 8

ATP (Adenosine triphosphate)

Answer 8

adenosine molecule with three phosphate groups attached which can release energy when one phosphate group is removed

Question 9

atypical

Answer 9

unusual results- usually the result of not taking enough samples, for example when throwing quadrats

Question 10

bioaccumulation

Answer 10

the build-up of toxic substances in living organisms

Question 11

biodiversity

Answer 11

total variation in an ecosystem including the variety that exists within a species and between different species

Question 12

biological control

Answer 12

the control of a pest by the introduction of a natural enemy or predator

Question 13

biotic factors

Answer 13

factors affecting a species that are directly related to, or are the result of, activities of living things

Question 14

by-product

Answer 14

a substance made when another substance is being produced e.g. oxygen is a by-product of photosynthesis

Question 15

carbohydrate

Answer 15

a molecule made of carbon, hydrogen and oxygen e.g. glucose, starch, cellulose

Question 16

carbon fixation

Answer 16

the second stage of photosynthesis in which ATP, hydrogen and carbon dioxide are used to produce glucose (and oxygen)

Question 17

carnivore

Answer 17

organism which only eats other consumers

Question 18

cellulose

Answer 18

structural carbohydrate of which plant cell walls are composed

Question 19

chlorophyll

Answer 19

green pigment in chloroplasts that absorb light energy for the process of photosynthesis

Question 20

chloroplast

Answer 20

organelle containing chlorophyll; the site of photosynthesis

Question 21

community

Answer 21

all the populations of all species in a habitat

Question 22

competition

Answer 22

when two organisms require the same resource and that resource is in short supply

Question 23

consumer

Answer 23

an organism that eats other organisms

Question 24

DDT

Answer 24

example of pesticide which can build up in the body f pests. its concentration increases as it is passed along the food chain leading to lethal concentrations in top predators

Question 25

decomposers

Answer 25

organisms (mainly bacteria fungi) which obtain energy by decomposing (breaking down) waste materials

Question 26

disadvantageous mutation

Answer 26

a random change to an organism's genetic material that us harmful and decreases the organism's chance of success

Question 27

distribution

Answer 27

the way in which something is spread over an area

Question 28

ecosystem

Answer 28

( ecosystem = community + habitat). a natural unit made up of one or more habitats and the community or communities of plants and animals there

Question 29

energy flow

Answer 29

the transfer of energy through food chain

Question 30

environment

Answer 30

the sum total of all surroundings of a living organism

Question 31

evolution

Answer 31

the change in genetic makeup of a population over successive generations, which may be caused by natural selection

Question 32

fauna

Answer 32

animal life

Question 33

fertiliser

Answer 33

a chemical or natural substance, containing nitrogen that is added to soil to increase crop yield

Question 34

food chain

Answer 34

diagram which shows how energy is passed from organism to organism

Question 35

food web

Answer 35

a network of food chains

Question 36

glucose (C6H12O6)

Answer 36

simple sugar used as the respiratory substrate in respiration and produced by photosynthesis

Question 37

GM crops

Answer 37

genetically modified plants which have had foreign genes (genes from other plants or animals) inserted into their genetic codes by genetic engineering to improve their characteristics

Question 38

grazing

Answer 38

when animals eat green plant material where only part of the (plant) structure is removed e.g. horse/cow/sheep eating grass

Question 39

habitat

Answer 39

the place where organisms live

Question 40

herbivore

Answer 40

organism which only eats plants

Question 41

humidity

Answer 41

the quantity of water vapour present

Question 42

indicator species

Answer 42

species that by their presence or absence or abundance indicate environmental quantity/ levels of pollution in an ecosystem

Question 43

interbreed

Answer 43

to sexually reproduce

Question 44

interspecific competition

Answer 44

occurs between organisms of different species competing for the same resource (which has limited supply)

Question 45

intraspecific competition

Answer 45

occurs between organisms of the same species competing for the same resource (which has a limited supply)

Question 46

leaching

Answer 46

when fertilisers are washed out of the soil by rainwater

Question 47

light intensity

Answer 47

a measurement of the brightness of light

Question 48

light meter

Answer 48

an instrument used to measure light intensity

Question 49

light reactions

Answer 49

first stage of photosynthesis (also known as photolysis) which needs light to occur. water is split into hydrogen and oxygen during this stage

Question 50

limiting factor

Answer 50

a variable that, when in short supply, can limit the rate of a chemical reaction

Question 51

moisture meter

Answer 51

an instrument used to measure the level of moisture

Question 52

mutagenic agent

Answer 52

are things (such as radiation) which can increase the frequency of mutations

Question 53

natural selection

Answer 53

a process where organisms possessing certain characteristics that make them better suited to a environment are selected and survive to reproduce. therefore, they pass on their advantageous characteristics to their offspring

Question 54

neutral mutation

Answer 54

a random change to an organism's genetic material that does not affect the survival of an organism

Question 55

niche

Answer 55

the niche of a species is its role in its habitat

Question 56

nitrate

Answer 56

nitrogen compounds which are taken by plants

Question 57

omnivore

Answer 57

organism which consumes both plants and animals (to obtain energy)

Question 58

paired key

Answer 58

a set of statements which cane be used to identify an organism

Question 59

pesticides

Answer 59

a chemical used to kill pests (organisms-insects/animals/plants- which damage crops)

Question 60

pitfall trap

Answer 60

a device used to trap invertebrates which are active on the ground surface

Question 61

pollution

Answer 61

the introduction into the environment of a substance which has harmful or poisonous effects. it can affect the air, fresh water, sea and land.

Question 62

population

Answer 62

the total number of living things of one species living in a a habitat

Question 63

predation

Answer 63

when one organism (predator) hunts and eats another (prey) as food

Question 64

predator

Answer 64

organisms which hunts and eats another animal

Question 65

prey

Answer 65

organisms which is hunted and eaten by predators

Question 66

producer

Answer 66

organisms which produce their own food (usually green plants by photosynthesis)

Question 67

protein

Answer 67

compound containing carbon, hydrogen, oxygen and nitrogen which are an essential part of living organisms