B17 - Organising an Ecosystem Flashcards

1
Q

Define population

A

A species that occupy the same habitat.

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

Define habitat

A

The place in which an organism lives.

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

Define community

A

Populations of different species interacting.

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

Define ecosystem

A

The interactions between the biotic and abiotic factors in an area.

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

What do food chains show?

A

Food chains show the feeding relationships of different organisms and the flow of energy between the organisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define biomass

A

The total mass of living material.

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

What are trophic levels?

A

The stages in a food chain.

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

What do arrows in a food chain represent?

A

The direction of biomass transfer.

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

Describe a simple food chain

A

producer → primary consumer → secondary consumer → tertiary consumer.

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

What is a producer?

A

An organism that makes its own food.

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

What types of organisms are primary producers?

A

Photosynthetic organisms like green plants and algae that trap energy from the sun.

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

What is a primary consumer?

A

An organism that feeds on producers.

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

What is a secondary consumer?

A

An organism that feeds on primary consumers.

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

What is a tertiary consumer?

A

An organism that feeds on secondary consumers.

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

What is a predator?

A

A consumer that kills and eats other animals.

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

What is prey?

A

An animal that is killed and eaten by another animal.

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

Describe the pattern of predators and prey in a stable community

A

The numbers of predators and prey rise and fall in cycles.

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

Why are producers the first trophic level?

A

● Producers provide all biomass for the food chain (production of glucose via photosynthesis).
● The rest of the food chain involves the transfer of this biomass.

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

What piece of apparatus is used to measure the abundance and distribution of organisms in an area?

A

Quadrat

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

What piece of apparatus is used to study the distribution of organisms across a gradient?

A

Belt transect

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

When considering the abundance of organisms, what is meant the term “mean”?

A

The average number of organisms.

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

How is the arithmetic mean calculated?

A

Sum of each number of each organism/the total number of each type of organism.

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

When considering the abundance of different organisms, what is meant by the term “mode”?

A

The most populous organism

24
Q

When considering the abundance of organisms, what is meant by the term “median”?

A

The organism that represents the middle value when the numbers of each organism are arranged from lowest to highest.

25
Q

Describe how materials cycle through the living and non-living components of an ecosystem

A

● Organisms take in elements from their surroundings e.g. soil, air.
● Elements converted to complex molecules which become biomass.
● Elements transferred along food chains.
● Elements returned to environment during excretion and decomposition of dead organisms.

26
Q

Give 3 molecules which are cycled through ecosystems

A

Oxygen, carbon dioxide and water.

27
Q

Describe the carbon cycle

A
  • Plants fix carbon dioxide into organic molecules during photosynthesis.
  • The organic carbon-containing molecules are passed onto organisms that eat the plants.
  • Carbon dioxide is released back into the atmosphere by respiration from animals and plants.
  • Burning fossil fuels also releases carbon dioxide into the atmosphere.
28
Q

Why is the carbon cycle important?

A

Carbon-containing molecules such as glucose are important for living organisms to grow and provide energy for vital functions within cells.

29
Q

Describe the water cycle

A
  • Water from lakes and oceans evaporates.
  • The evaporated water condenses into clouds and returns to earth as precipitation.
  • The water from precipitation is useful for life on land.
  • The water then returns to rivers and oceans through surface runoff.
30
Q

Why is the water cycle important?

A

Living organisms require water and the water cycle provides organisms on land with a continuous supply of water.

31
Q

Why are microorganisms important for the cycling of materials through an ecosystem?

A

Microorganisms (bacteria and fungi) return carbon to the environment by releasing carbon dioxide through respiration while they decompose dead matter. The decomposition of dead matter in soil returns mineral ions to the environment for other organisms to use e.g. plants use mineral ions for growth.

32
Q

What is meant by decomposition?
(biology only)

A

The breakdown of dead materials into simpler organic matter

33
Q

How do decomposers break down dead matter?
(biology only)

A

Decomposers release enzymes which catalyse the breakdown of dead material into smaller molecules.

34
Q

What are the two types of decomposition? (biology only)

A

Aerobic decomposition (with oxygen)

Anaerobic decomposition (without oxygen)

35
Q

What factors affect the rate of decomposition? (biology only)

A

● Oxygen availability
● Temperature
● Water content

36
Q

Why is oxygen required for decomposition? (biology only)

A

Most decomposers require oxygen for aerobic respiration.

37
Q

How does the availability of oxygen affect the rate of decomposition? (biology only)

A

● As oxygen levels increase, the rate of decomposition increases.
● As oxygen levels decrease, the rate of decomposition decreases.

38
Q

Why can decomposition still occur in the absence of oxygen?
(biology only)

A

Some decomposers respire anaerobically.*
*However, the rate of decomposition is slower as anaerobic respiration produces less energy.

39
Q

How does soil water content affect the rate of decomposition? (biology only)

A

Decomposers require water to survive:
● In moist conditions the rate of decomposition is high.
● In waterlogged soils there is little oxygen for respiration so the rate of decomposition decreases.

40
Q

Why does decomposition require water?
(biology only)

A

Water is required for the secretion of enzymes and absorption of dissolved molecules.

41
Q

How does temperature affect the rate of decomposition?
(biology only)

A

Decomposers release enzymes:
● Rate highest at 50°C (optimum temperature for enzymes).
● Lower temperatures, enzymes work too slowly, rate decreases.
● High temperatures, enzymes denature, decomposition stops.

42
Q

How is the rate of change calculated when considering the decay of biological material? (biology only)

A

Rate of change = Change in value / Change in time

Where value is a measurable variable associated with the decay of the material

43
Q

What is compost?
(biology only)

A

The nutrient-rich product of the rapid decay of waste biological material (dead plants and animal waste) in optimum conditions set by gardeners and farmers.

44
Q

How is compost used?
(biology only)

A

Used as natural fertiliser to promote growth of crops or garden plants.

45
Q

Describe how biogas generators work
(biology only)

A

Biogas generators provide methane gas for fuel through anaerobic decomposition that occurs in animal waste.

46
Q

Describe how environmental conditions affect communities
(biology only) (higher only)

A

● Environmental conditions e.g. temperature, soil pH, light intensity affect the abundance and distribution of organisms within communities.
● e.g rising global temperatures have been linked to the extinction of frog species (their thin skin makes them more vulnerable to temperature changes).

47
Q

How can different temperatures be bad for certain communities?

A
  • If the temperature is too low, growth will be slower as organisms will use more energy to stay warm
  • If the temperature is too high, organisms can die and water will become limited as evaporation increases
48
Q

How can changes in water levels affect ecosystems?
(Higher)

A
  • Animals may have to migrate to find water.
  • Melting ice caps may destroy the habitats of some animals (either animals living in icy regions or by sea level rise).
49
Q

How can atmospheric gases affect ecosystems?
(Higher)

A
  • Some organisms cannot survive when certain gases are present.
  • Polluted water can cause illness to animals that drink it.
50
Q

What detrimental impacts can sulfur dioxide have on the environment?

A
  • Formed when fossil fuels containing impurities are burnt.
  • Sulfur dioxide can dissolve in water to form acid rain which can erode buildings and pollute water sources.
51
Q

What detrimental impacts can carbon monoxide have on the environment?

A
  • Carbon monoxide is formed from the incomplete combustion of fossil fuels.
  • Carbon monoxide binds irreversibly to haemoglobin which prevents it from carrying oxygen.
  • Too much exposure can cause unconsciousness and death.
52
Q

Name 5 greenhouse gases

A
  • Water vapour
  • Carbon dioxide
  • Nitrous oxide
  • Methane
  • CFCs
53
Q

Give 3 human activities that contribute to greenhouse gases

A
  • Burning fossil fuels
  • Deforestation
  • Large scale livestock farming
54
Q

How do greenhouse gases lead to global warming?

A
  • Greenhouse gases allow heat from the sun to enter the atmosphere.
  • The gases act as a ‘blanket’ and trap the heat in the atmosphere.
55
Q

State 3 negative consequences of global warming

A
  • Sea level rise caused by melting icebergs.
  • Disrupted farming and agriculture.
  • Increased spread of diseases in warmer climates.