Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GCSE OCR Biology > B4.1 Ecosystems > Flashcards

B4.1 Ecosystems Flashcards

You may prefer our related Brainscape-certified flashcards:
GCSE Religious Studies - Edexcel Route A flashcards GCSE Religious Studies - Eduqas Route A flashcards AP® Biology flashcards GCSE Geography - AQA flashcards Biology 101 flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route B flashcards
1
Q

What is an ecosystem made up of?

A

All the living organisms and physical conditions in an area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define community.

A

The organisms within the ecosystem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define habitat.

A

Where organisms live

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define population?

A

The total number of organisms of each species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are organisms grouped into? What is their role?

A
  • Producers - organisms that make their own food by photosynthesis. They include all plants and algae
  • Consumers - organisms that cannot make their own food. They have to eat other organisms to gain energy.All animals are consumers.
  • Decomposers - a special group of consumers. They gain their energy by feeding on dead or decaying material.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What can glucose be converted into?

A

Carbohydrates, fats and proteins which are used as energy stores and for growth and repair.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define biomass?

A

The dry mass of all of the living organisms in an area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does a food chain show?

A

The transfer of biomass and energy transfer from one organism to the next.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define food web.

A

A series of interlinked food chains.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define omnivore.

A

Animals which eat both animals and plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define carnivore.

A

an organism that mostly eats meat, or the flesh of animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define herbivore.

A

an animal that mainly eats plants.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define biotic factors.

A

The living factors of an ecosystem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define abiotic factors

A

The non living factors of an ecosystem e.g rainfall or temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do organisms compete for?

A

Food - space - mates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does temperature affect communities

A

Temperature has its greatest effect on the enzymes that control metabolic reactions. Plants develop more rapidly in warmer temperatures.

SIDE NOTE: Warm blooded animals are less affected by their external environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does light intensity affect communities?

A

Light is required for photosynthesis. In general the greater the light availability the greater the success of a plant.

SIDE NOTE: in areas of low light plants often have larger leaves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does moisture levels affect communities?

A

A lack of water leads to death in most plants and animals.
A lack of water causes most plants to wilt because water is required to keep their cells turgid, keeping plants upright.
Water is used in photosythesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does soil pH affect communities?

A

The pH of soil affects the biological activity in the soil and the availability of certain minerals.
Some plants grow better in acidic soils such as farms.
Some plants grow better in alkaline soils such as cucumbers and cauliflower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is used to measure the following abiotic factors:

Light intensity
Availability of moisture
pH
Temperature

A

Light meter
Humidity sensor
pH probe
thermometer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What do plants need to survive?

A

Light
Water
Carbon dioxide
Minerals
Space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do animals need to survive?

A

Food
Water
Mates
Space
Shelter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is interdependence?

A

How different organisms depend on each other within a community.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the three main types of interdependence?

A

Predation
Mutualism
Parasitism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is predation?

A

The relationship between a predator and a prey species.The size of the predator population directly affects the size of the prey population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is mutualism?

A

Where both organisms benefit from the relationship e.g bees and flowers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is parasitism ?

A

Where only one organism (the parasite) gains from the relationship. The organism. it lives off (the host) suffers.
e.g headlice and humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What do pyramids of biomass show?

A

Show the population at each tropic level.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is a pyramid of biomass structured

A

The producer is placed at the base, with the next tropic levels placed above.

30
Q

What does the bar width represent in a pyramid of biomass?

A

The number of organisms present

31
Q

What is the general pattern for a pyramid of biomass?

A

The size of the population generally increases ,but the number of organisms decreases.

32
Q

How do you calculate biomass at each trophic level?

A

The average mass of each organism x Number of organisms present

33
Q

State a disadvantage of collecting biomass data?

A

Biomass data is difficult to obtain as the organism needs to be killed and heated in an oven to remove any water, until a constant dry mass is obtained.

34
Q

What are the steps to draw a pyramid of biomass?

A

Step 1: Decide on a sale to represent the biomass of each species

Step 2: Calculate the width of each bar bye dividing each biomass by the scale factor

Step 3: Use the measurements to draw each bar in the pyramid

35
Q

How is energy transferred to producers?

A

Sunlight

36
Q

How much energy do producers transfer into chemical stores?

A

1%

37
Q

How much energy is transferred to each trophic level?

A

10%

38
Q

How is biomass lost in organisms?

A

Not all of an organism is eaten

Some of the biomass is used in respiration

Some parts of an organism cannot be digested, such as hair and teeth

Waste products produced by the body are lost through excretion. e.g urea is lost in urine

39
Q

What is egestion?

A

The release of undigested substances as feces

40
Q

What is excretion?

A

The removal of toxic materials, waste products of metabolism and excess substances from organisms

41
Q

How do you calculate the efficiency of biomass transfer?

A

[Biomass available after the transfer (g or kg) / Biomass available before the transfer (g or kg)] X 100

42
Q

Where do plants get their nutrients?

A

Soil

43
Q

Name three molecules which are cycled through ecosystems

A

Carbon
Nitrogen
Water

44
Q

What is carbon used for?

A

Fats
Proteins
DNA

45
Q

Where can carbon become trapped?

A

Oceans and rocks

46
Q

How much of the atmosphere is nitrogen?

A

80%

47
Q

What do organisms use nitrogen for?

A

To make DNA and proteins.

48
Q

How does nitrogen exist in soil?

A

As nitrates dissolved in water

49
Q

Describe how nitrogen is cycled through an ecosystem.

A
  1. Nitrogen is fixed by lightening and nitrogen-fixing bacteria
  2. Denitrifying bacteria release nitrites in soil into nitrogen in the air
  3. Denitrifying bacteria convert nitrates in soil into nitrites, and nitrites to ammonia
  4. Nitrifying bacteria convert ammonia in soil into nitrites, and nitrites to nitrates
  5. Nitrates in soil taken up by plants and combined with carbohydrates to make plant proteins.
  6. Plant proteins either eaten by other animals to form animal protein or die and decompose to release ammonia into soil
  7. Animals excrete ammonia and die and decompose to release ammonia into soil.
50
Q

Where does the water cycle move from?

A

Through the atmosphere ,soil, rivers , lakes and oceans

51
Q

What can excess use of nitrates lead to?

A

eutrophication

52
Q

What is the carbon cycle?

A

The process by which carbon is cycled through the atmosphere, the Earth, plants and animals

53
Q

How is carbon removed from the atmosphere?

A

Carbon dioxide is removed from the environment during photosynthesis.

When animals eat plants, carbon in the plant is transferred to the animal. Some of this carbon is used to produce fats and proteins in the animals body

Glucose is used in plants to grow and develop.The carbon is part of their extra biomass

54
Q

How is carbon released back into the atmosphere?

A

Respiration - All living organisms respire to transfer energy from chemical stores in food. Carbon dioxide is produced and released.

Decomposition - When plants and algae and animals die decomposers break down their remains, reeling carbon dioxide as they respire.

Burning fossil fuels - Fossil fuels are a store of carbon. When they burn this trapped carbon is released.

55
Q

What are some examples of fossil fuels

A

Coal
Oil
Natural gas

56
Q

Why does the level of atmospheric carbon dioxide vary?

A

photosynthesis only takes place in the light, so carbon dioxide is only removed from the atmosphere in the day time

Respiration is carried out throughout the day and night, releasing carbon dioxide at a relatively consistent rate.

57
Q

What are decomposers?

A

micro-organisms that break down or decay dead organic material and waste at a microscopic level

58
Q

What are saprophytes?

A

A plant, fungus, or microorganism that lives on dead or decaying organic matter.

59
Q

What are detritivores?

A

Small animals that speed up decomposition by shredding organic material into very small pieces.

60
Q

Name examples of Detritivores and the material they break down

A

earthworm - leaves

woodlouse - wood

maggot - animal material

61
Q

How do bacteria and fungi break down substances in organic matter?

A

They release enzymes and then absorb the soluble nutrients and use them for growth and an energy store

62
Q

How can nutrients be passed on to other organisms?

A

Be eaten or directly released into soil

63
Q

What factors affect the rate of decomposition?

A

Warm temperatures
Moist environments
Aerobic conditions

64
Q

Explain how warm temperatures affect the rate of decomposition

A

Enzymes work faster is higher temperatures yet not too high as to avoid denaturing which prevents decomposition occurring

65
Q

Explain how moist environments affect the rate of decomposition

A

If not enough water is available, reactions within the microorganisms will slow down or be prevented.
This reduces or stops the process of decomposition

66
Q

Explain how aerobic conditions affect the rate of decomposition?

A

Oxygen is needed for the microorganisms to respire.
Anaerobic conditions will prevent most forms of decomposition as the micro-organisms cannot survive in this environment

67
Q

How do you calculate the rate of decay of biological material?

A

Change in mass (g) / Time (day)

68
Q

Why is recycling in ecosystems necessary?

A

To create a continuous flow of nutrients

69
Q

Describe how carbon is cycled through an ecosystem.

A
  1. Carbon dioxide is fixed through photosynthesis
  2. Respiration releases carbon dioxide
  3. Decomposition releases carbon dioxide
  4. Combustion releases carbon dioxide
70
Q

Describe how water is cycled through an ecosystem.

A
  1. Water evaporates from rivers and lakes and from transpiration
  2. Water condenses as clouds
  3. Water is returned through precipitation

GCSE OCR Biology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions