Nat 5 - Life On Earth Flashcards

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1
Q

Define the term biodiversity

A

Biodiversity is the total variation that exists amongst all living things on Earth.

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2
Q

Name three things that can affect biodiversity

A

Pollution, habitat destruction and overfishing

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3
Q

Define the term biotic factor

A

Biotic factors are factors that are caused by living things

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4
Q

Define the term abiotic factor

A

Abiotic factors are factors that are caused by non-living factors

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5
Q

Name 4 biotic factors

A

Food availability, disease, grazing and predation

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6
Q

Name 4 abiotic factors

A

Light intensity, pH, temperature and oxygen levels

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7
Q

Define the term biome

A

A biome is a region of the plant that has similar climate, flora (plants) and fauna (animals). It is made up of many similar ecosystems

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8
Q

Name 3 examples of biomes

A

Freshwater, tropical rainforest and grassland

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9
Q

State 2 factors that can influence the global distribution of biomes

A

Temperature and rainfall

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10
Q

Define the term ecosystem

A

An ecosystem is the entire community of living organisms in a habitat and the non-living components with which the organisms interact

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11
Q

Define the term habitat

A

A habitat is the place where an organism lives

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12
Q

Define the term community

A

A community is a group of organisms of one species in an ecosystem

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13
Q

Define the term population

A

A population is all of the living organisms within a particular habitat

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14
Q

Define the term niche

A

A niche is the role that an organism plays within a community

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15
Q

Define the term food chain

A

A food chain shows feeding relationships of animals and plants in an ecosystem

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16
Q

State what the arrows in a food chain show

A

The arrows in a food chain show the direction of energy flow through an ecosystem

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17
Q

Define the term producer

A

A producer is a plant that produced its own food using light energy in photosynthesis

18
Q

Define the term consumer

A

A consumer is an organism which eats other organisms in a food chain

19
Q

Define the term decomposer

A

A decomposer is an organism that breaks down dead plant and animal material

20
Q

Define the term herbivore

A

A herbivore is an organism that only eats plants

21
Q

Define the term carnivore

A

A carnivore is an organism that only eats animals

22
Q

Define the term omnivore

A

An omnivore is an organism that eats plant and animal material

23
Q

Explain the difference between primary, secondary and tertiary consumers

A

The primary consumer is a herbivore which eats the plant, the secondary consumer eats the primary consumer and the tertiary consumer eats the secondary consumer

24
Q

State how much percent of energy is lost at each level of a food chain

A

90% lost, 10% passed on

25
Q

Name 3 ways that energy is lost

A

Heat, movement and undigested waste

26
Q

Define a pyramid of numbers

A

A pyramid of numbers shows the number of organisms at each level of a food chain in an area (m2)

27
Q

Explain why some pyramids of numbers are irregular in shape

A

Sometimes a tree is the producer or a flea is the tertiary consumer

28
Q

Define a pyramid of biomass

A

A pyramid of biomass shows the total mass of organisms at each stage of a food chain

29
Q

Define a pyramid of energy

A

A pyramid of energy shows the energy available at each stage of a food chain

30
Q

Discuss which of the 3 types of pyramid most accurately demonstrates a food chain

A

Pyramid of energy because it shows that 10% of energy is always passed on

31
Q

Define the term competition

A

Competition occurs in an ecosystem when two or more members of the community need a particular resource that is in short supply

32
Q

Name 3 resources that plants compete for

A

Light, water and nutrients

33
Q

Name 3 resources that animals compete for

A

Space, food, water and mates

34
Q

Define the term interspecific competition

A

When competition occurs between members of different species

35
Q

Define the term intraspecific competition

A

When competition occurs between members of the same species

36
Q

Describe the intensity of intraspecific competition compared to interspecific competition and explain why this is the case

A

Intraspecific competition is more intense because organisms compete for the exact same resources

37
Q

State the molecule needed by plants and animals that contains nitrogen

A

Protein

38
Q

State the form of nitrogen that plants can take up through their roots

A

Nitrates

39
Q

Name the 3 types of bacteria involved in the nitrogen cycle

A

Nitrifying bacteria, denitrifying bacteria and nitrogen fixing bacteria

40
Q

Describe the role of nitrifying bacteria

A

It causes ammonium compounds to be converted into nitrites and nitrates

41
Q

Describe the role of denitrifying bacteria

A

It removes nitrates from the soil by converting it to nitrogen gas

42
Q

Describe the role of nitrogen fixing bacteria

A

It absorbs nitrogen from the atmosphere and converts it into ammonium compounds