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Flashcards in Energy flow in ecosystems Deck (98):
1

ecology

the study of living things and their interactions with each other and their environment

2

ecosystem

a self-supporting sysetm of organisms interacting with each other and their environment

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habitat

a place within an ecosystem where specific organisms live, e.g. pond or woodland

4

population

all of the organisms of a particular species found in an ecosystem

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community

all the different species living in an ecosystem

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competeition

the struggle for resources

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biotic factor

all biological (living) components of the ecosystem (predation, food, competition, decomposition)

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abiotic factor

(all the non-biological components of the ecosystem (including water, air, temperature, sunlight, etc...)

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producer

organism that can make its own food (= autotroph)

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primary consumer

organism that obtains energy by feeding on producers (=heterotroph)

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secondary consumer

organism that obtains energy by feeding on primary consumer (= heterotroph)

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herbivore

animal that feeds on plants only

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carnivore

animal that feeds on other animals only

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tertiary consumer

animal that has no natural predators

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prey

animal hunted and killed by another animal for food

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predator

animal that preys on other animals

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detritivore

organism that feeds on dead/ decaying organic material (e.g. worm vulture) (=saprotroph)

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decomposers

organism that decompose (break down) organic material (e.g. bacteria + fungi)

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heterotroph

organism that feeds on other organisms (= consumer)

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autotroph

organism that can make its own food (= producer)

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saprotroph

organism that feeds on decaying organic material (= detritivore)

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food chain

shows simple feeding relationships within an ecosystem

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food web

shows complex feeding relationships within an ecosystem

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trophic level

stage in a food chain (= feeding level)

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pyramids of number

represents the number of organisms in each trophic level in a food chain (irrespective of their mass)

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pyramids of biomass

represents the total mass of all the organisms in each trophic level (irrespective of their number)

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pyramid of energy

shows the energy transferred through each trophic level in a food chain

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quadrat

a square frame (sometimes gridded) for sampling organisms

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The organisms: leaf, worm, mouse, owl

Label their trophic levels

Whether their are a producer or consumer and which consumer they are (primary, secondary...)

Whether they are prey or a predator

Whether they are a herbivore or carnivore

 

leaf → worm → mouse →owl

trophic level 1 → trophic level 2 → trophic level 3 → trophic level 4

prodcuer → primary consumer → secondary consumer → tertiary consumer

(N/A) → herbivore → carnivore → top carnivore

(N/A) → prey → prey, predator → predator

30

What would happen if the fox population decreased? (two outcomes)

squirrel population increases

woodmouse population increases

 

31

What would happen if the caterpillar population decreased? (two outcomes)

shrew population decreases

earthworm population decreases

32

Food chains show the direction of ... transferred between the trophic levels

Energy is transferred as ... (in food molecules)

Chemical energy is stored as new ... (mass of an organism)

Food chains show the direction of energy transferred between the trophic levels

Energy is transferred as chemical energy (in food molecules)

Chemical energy is stored as new biomass (mass of an organism)

33

The population of each organism in a food chain can be shown in a pyramid of ...

The ... of each box is determined by the number of organisms at each trophic level

The population of each organism in a food chain can be shown in a pyramid of numbers

The width of each box is determined by the number of organisms at each trophic level

34

Sketch a pyramid of numbers for this food chain:

50 clovers → 20 snails → 5 thrush → one sparrowhawk

35

The ... of each trophic level in a food chain is shown in a pyramid of biomass

The biomass of each trophic level in a food chain is shown in a pyramid of biomass

36

Sketch a pyramid of biomass for this food chain:

oak tree → caterpillar → mouse → owl

(1 x 50kg) → (50 x 0.2kg) → (5 x 0.5kg) → (1 x 1kg)

oak tree → caterpillar → mouse → owl

(50kg) → (10kg) → (2.5kg) → (1kg)

37

Between each trophic in a food chain, not all energy is converted into new ... in growth

Some ... is ...

Up to ...% of energy can be lost in trophic levels

Between each trophic in a food chain, not all energy is converted into new biomass in growth

Some energy is lost

Up to 90% of energy can be lost in trophic levels 

38

How is energy lost between each trophic level?

some energy is released in respiration (e.g. for movement or body heat)

not all energy is digested, some is excreted

some is converted into new biomass

not all of the organism is eaten

39

How can food production be made more efficient?

by decreasing the number of trophic levels in food chains

by limiting the movement of animals, so that less energy is lost

by increasing the temperature, so that less energy is lost through body heat - this is done by keeping the animals close together in a confined space

 

40

How are organisms in an ecostsytem continually interacting with each other?

e.g. through deeding or competition

41

How much energy eaten in food is used to build new biomass (new cells)?

a very small fraction - often less that 10%

42

Is it more efficient to eat plants or eat animals? Why?

it is more efficient to eat plants

you have decreased the number of trophic levels in the food chain

43

Why is it difficult to determine the number of organisms in a habitat?

plants could be spread out unevenly

some organisms can move (e.g. animals)

it wouldtake an incredibly long time - time constraints

44

What is an ideal sample size of an area?

10% of the area

45

What is a quadrat?

a square frame used for sampling

46

How do you use a quadrat?

layo ut a tape measure to mark out a sampling field

use a random number generator to get some coordinates (e.g. 4, 2)

count the number of organisms present in the quadrat

count the number of organisms found at the other coordinates (i.e. do repeats)

calculate the mean and use it to estimate the entire population size

47

In an experiment to investigate the population size of flowering plants, what type of variable is:

the habitat

the number of flowering plants

the habitat = independent, categorical

the number of flowering plants = dependent, discrete

48

For much of the year at ground level in Birnham Wood it is very dark during the day. However, some small plants do grow there. One of them is the Bird's-Nest Orchid, which has pale brown leaves.

Suggest why it is dark at ground level in Birnham WOod for much of the year

the light is blocked by trees

49

For much of the year at ground level in Birnham Wood it is very dark during the day. However, some small plants do grow there. One of them is the Bird's-Nest Orchid, which has pale brown leaves.

The Bird's-Nest Orchid is not green like most other plants. Explain why the green colour is important to most plants

The green pigment in most plants is chlorophyll which is used in photosynthesis for plants to make their own food

50

For much of the year at ground level in Birnham Wood it is very dark during the day. However, some small plants do grow there. One of them is the Bird's-Nest Orchid, which has pale brown leaves.

Suggest how the Bird's-Nest Orchid is able to survive even though it is not green

it feeds on dead material/carnivorous

51

This is a food chain from a pond:

microscopic plants → microscopic animals → insects → fish

What is the term used to describe the fish?

top carnivore

52

Why is it an advantage for an animal at the top of a food web to feed on more than one type of organism?

it is easier to find prey / less competition

they can survive if one organism dies out

can feed in different seasons

better chance of a balanced diet

 

53

Why is it unusual to find food chains with more than five trophic levels?

most energy would be lost through, for example, respiration and excretion

energy decreases as the trophic level increases

54

What is decomposition and what does this process release?

decomposition is the breakdown of dead organisms, or other material, such as bread

this process releases inorganic minerals, such as nitrate or phosphate, and carbon dioxide into the air in respiration

55

Name two groups of organisms that can act as decomposers in food chains

bacteria

fungi

56

Describe the role of decomposers in the carbon cycle

they breakdown the remains of dead plants and animals and, in doing so, release carbon dioxide through respiration

57

Describe an investigation you could carry out in the laboratory to find theeffect of light intensity on the growth of plants. You should include ful experimental details in your account

Light intenisty is the independent variable of this experiment so I will choose three different light intensities to test on the plant; no light, dim light and harsh light

To make it a fair test, I will use the same species of plant and give the plant the same volume of water and keep them at room temperature - these are my control variables

For each of the light intensities I will measure plant growth over one week by measuring the height of the plant using a rule - this is my dependent variable

I will repeat my experiment three times to increase the reliability of my results

58

Describe how you could compare the population size of a plant growing in two different places. One place is on the side of the hill and the other place is on a piece of flat ground

I would plant the same specied of plant in a 0.5m2 quadrat

One quadrat would be on the side of the hill and the other on a piece of flat ground

After a week, i would count how many plants had grown in each quadrat

I would repeat the experiment three times

59

What seven ways can you improve crop yield?

soil minerals

soil structure

soil pH

water

carbon dioxde

heat

light

60

How do you control soil minerals? What is the reason for controlling this?

how: adding inorganic fertiliser or manure to soil

reason: extra minerals increase plant rate

 

61

How do you control soil structure? What is the reason for controlling this?

how: ploughing fields to break up contact soil

reason: allows better uptake of minerals and water because it's easier for roots to grow in soil

62

How do you control soil pH? What is the reason for controlling this?

how: adding lime to acidic soil

reason: low pH can reduce uptake of minerals

63

How do you control water? What is the reason for controlling this?

how: watering

reason: required for photosynthesis

64

How do you control carbon dioxide? What is the reason for controlling this?

how: greenhouse (e.g. burning fossil fuels)

reason: required for photosynthesis

65

How do you control heat? What is the reason for controlling this?

how: greenhouse (e.g. burning fossil fuels)

reason: required for photosynthesis

66

How do you control light? What is the reason for controlling this?

how: greenhouse (e.g. artificial light)
reason: required for photosynthesis

67

What are pests?

organisms that reduce the yield of crop plants or farm animals (can be plants, animals, fungi, bacteria or viruses)

68

What do these kill:

herbicides

insecticides

fungicides

molluscides

herbicides kill plant petss

insecticides kill insects 

fungicides kill fungi

molluscides kill molluscs

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What are the advantages of pest control?

higher crop yield

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What are the disadvanatges of pest control?

expensive

pest reistance

environmental damage

bioaccumulation

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What is bioaccumulation?

pesticides stored in fatty tissue

72

What is biomagnification

pesticide concentration increases in higher levels of food chain

73

How does biological pest control work?

natural predators of pests

parasites of pests

pathogenic microorganisms (to cause disease of pest)

introduction of sterile males of pest (to prevent reproduction)

use of pheromones (to attract and trap pests)

herbivores (to reduce weeds)

74

How does crop rotation work?

used instead of monocultures

pests die out as they can't live with the new crops

pests live in a particular area, feeding on that crop - if you change the crop, the pests die out as they can't feed anymore

75

A farmer releases ladybird onto his tomato plants to reduce the number of aphids (ladybirds eat aphids that feed on tomatoes). What is the name given to this meyhod of reducig the number of insect pest?

biological control

76

Describe the disadvantages of using pesticides

bioaccumulation

affects other species

poisonous to humans

food chain disruption

pollution

needs reapplication

77

How do insect pests would affect crop yield?

crop yield would decrease

insect pests consme crops so there is less surface area so less photosynthesis

78

Explain why farmers often spray pesticide onto their crops

pesticides kill the organisms (pests) that reduces the yield of their crops

this protects their crops and allows for higher crop yield

79

Explain how fertilisers increase the yield of crops

fertilisers contain minerals, e.g. nitrate for amino acids, proten for chlorophyll

this increases the plant rate

80

Explain why increasing the temperature in a glashouse would affect the yield of crops

temperature is required for photosynthesis

the higher the temperature, the higher the rate of photosynthesis

this increases yield as plants grow more and grow faster

81

What is fish farming?

the raising of fish commercially in tanks or encolsures, usually for food

82

What are the advantages of fish farming?

meets quality of fish

water quality can be carefully monitored inclusing oxygenation and temperature (fish are kept in large seawater tanks)

shortfall of fish can be carefully monitored including diet and frequency of feeding

fish are protected against predators (not present in tanks) and parasites (by using pesticides)

selective breeding programmes can be used to improve the quality of fish (e.g. faster growth)

83

What are the disadvantages of fish farming?

potential for spreading of disease is larger (fish closer together)

overuse of antibiotics to treat disease

pollution of water with fish faeces and food pellets (can lead to eutrophication)

pesticides used to kill parasites can be toxic

food pellets derived from wild fish - leads to a further reduction in wild fish stock

84

What is eutrophication?

an increase of nutirents in water lead to an overgrowth of algae or plants

some planst/algae die

decomposers increase using O2 (aerobic respiration)

fish die as oxygen decreases

85

Why is protein important for growth?

amino acids

hormones

bone

DNA

tissue

muscle

86

Suggest why it is important that water can circulate through the cages

circultaing water removes such as faeces and urine

prevents stagnation and disease/pollution

87

Suggest why fish farmers supply small amounts of food at regular intervals

so all the food is eaten and there is less waste

88

Suggest why fish farmers aim to have Food Conversion Efficiency

there is an economic benefit; there is more growth from a small amount of food

89

What is an intraspecific competition?

competition between members of the same species

90

What is an interspecific competition?

competition between differnt species

91

Describe ways in which fish farmers can reduce intraspecific competition?

increase the cage size so there is no overcrowding

supply enough food

92

Describe ways in which fish farmers can reduce interspecific competition?

only have one type of fish per cage

stop other fish entering the cage by separating the cages with mesh

93

Give one reason why dish are an important food source for humans?

fish are a source of protein

94

Give two ways in which fish farmers maintain water quality and how it is achieved

prevent build up of food by feeding in small, regular amounts

remove waste by filtering the water

95

Suggest five ways in which a fish farm might cause harm to the local ecosystem

release of waste

release of chemicals

release of bacetria

disease can infect wild fish

habitat destruction by floowing/building the fish farms

96

Give five advantages of fish farming compared to catching fish in the wild

guaranteed harvest

no need to buy boat or fuel

it is not dangerous

no depleteing wild fish stocks

no overfishing - conserves endagered species

 

97

Plan an investigation to compare the effect of two different types of fish food on the growth of fish

C: use different fish foods

O: same species and size of fish

R: several fish used

M: growth measured in mass

M: make the time period for the experiment more than one week

S: control the temperature and mass of food by regular feeding

98

Describe and explain three different ways a fish farmer can help to increse the yield of fish

protect from predators by covering ponds with nets

prevent disease by using antibiotics

control water quality by filtering out nitrogenous water