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gcses > biology topic 7 > Flashcards

biology topic 7 Flashcards

1
Q

why do animals have adaptations

A

enable them to survive the conditions in which they normally live.

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2
Q

what can adaptations be

A

behavioural (actions an organisms takes) - migration

structural (how an organism is built) – fur, hair

functional (how the organism works) – produces more or less
urine depending on water availability

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3
Q

give some features that would make an environment extreme

A

high temperature, pressure or salt concentration.

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4
Q

what are extremophiles

A

organisms adapted to surviving in extreme conditions as they have enzymes
adapted for survival in these extreme environments

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5
Q

what do Plants in a community or
habitat compete with each other for

A

Light

Space

Water and mineral ions from the soil

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6
Q

what do Animals in a community often compete with each other for

A

Food

Mates

Territory

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7
Q

what are abiotic factors

A

non-living factors

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8
Q

what are biotic factors

A

living factors

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9
Q

what are examples of abiotic factors that effect a community

A

Light Intensity

Temperature

Carbon dioxide levels for plants

Oxygen levels for aquatic animals

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10
Q

what are Biotic factors
which can affect a community

A

New predators

Low food availability

New pathogens

One species outcompeting
another

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11
Q

describe how you would do a quadrats practical

A

1) quadrat placed randomly in field - randomly generate a coordinate grid for the field

2) repeat 10 times

3) count number of organisms in each quadrat

4) use number of organisms, area of quadrant and area of field to estimate population

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12
Q

describe how you would do a transects practical

A

1) place a [30-m] tape measure across field

2) place quadrats next to the tape

3) count number of plants in every quadrat

4) repeat every 2 meters

increase precision - do it every metre
increase accuracy - repeat and calculate mean

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13
Q

describe the carbon cycle

A

1) plants photosynthesise

photosynthesis takes in CO2

plants use carbon dioxide to make carbohydrate / protein / fat / organic
compounds / named (e.g. enzymes / cellulose)

2) plants respire

animals respire

respiration releases CO2

3) plants and animals die

Microorganisms enzymes decay / decompose dead organisms

microorganisms respire to release CO2

4) Dead organisms form fossil fuels over millions of years

Fossil fuels burnt to release CO2

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14
Q

describe nitrogen recycling

A

Decay microorganisms release nitrate ions into the soil

nitrate ions taken in by roots

using active transport

to make amino acids / proteins

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15
Q

describe the water cycle

A

Water evaporates from the surface of the sea. Heat from the sun speeds up this process and so does the wind. Water vapour in the atmosphere cools down and condenses to form billions of tiny water droplets. Some of the droplets join together and fall as rain.

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16
Q

what are the best conditions for decay

A

Water

Oxygen

Warmth

Microorganisms called decomposers - these are bacteria or fungi.

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17
Q

describe the decay practical

A

Get 2 boiling tubes containing 20ml milk and 5cm3 lipase

Add five drops of the Cresol red and 5cm3 sodium carbonate solution to the milk tube. The solution
should be purple

Put both tubes in a water bath at 10⁰C

Wait until the contents reach the same temperature as the water bath.

Transfer 1cm3 of lipase from the ‘lipase’ tube to the ‘milk’ tube.

Immediately start the stopwatch

Stir the contents of the ‘milk’ boiling tube until the solution turns yellow.

Record the time taken for the colour to change to yellow, in seconds.

Repeat the investigation for different temperatures of water bath.

Explanation

Lipase breaks down fats in milk into glycerol and fatty ACIDS. Cresol red is purple in alkali, yellow in acid

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18
Q

what do Biogas generators do

A

anaerobically digest waste biological material and produce methane.

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19
Q

what can methane gas be used as

A

fule

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20
Q

what changes may occur due to environmental changes

A

seasonal e.g. migration of wildebeast

geographic e.g. coastal soil is more salty

caused by human interaction e.g.
introduction of a new predator to an area or buildings.

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21
Q

what is biodiversity

A

Biodiversity is the variety of all the different species of organisms on
Earth, or within an ecosystem.

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22
Q

why is biodiversity important

A

A high biodiversity ensures
the stability of ecosystems by
reducing the dependence of
one species on another for
food, shelter and the
maintenance of the physical
environment.

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23
Q

what is interdependence

A

Species in a community rely on each other for survival

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24
Q

give examples of interdependence

A

Many flowering plants rely on insects like bees or butterflies for pollination.

Animals or birds may carry plant
seeds away from the parent plant
to reduce competition.

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25
Q

what is A stable community

A

A stable community is one where all the species and environmental factors are in balance so that the population sizes remain fairly constant.

26
Q

give an Example of a stable community

A

As the number of prey increase, so too do the number of predators.

As the number of predators increase, the number of prey decrease

Fewer prey means less food for predators so they too start to decrease

27
Q

give examples of activities that have a negative effect on biodiversity

A

How we manage waste

How we use land

Deforestation

Global warming

28
Q

what is water pollution

A

Sewage, artificial fertilisers and toxic
chemicals may enter lakes, rivers or the sea.

29
Q

what is Eutrophication.

A

Algae in the water grow rapidly due to
fertiliser. Reduces amount of light

for plants at the bottom of the pond so they die.
No plants = no photosynthesis = no oxygen

Decay uses up oxygen so other living
organisms (fish) die as well.

30
Q

what is Bioaccumulation

A

Bioaccumulation is the build-up of toxins along a food chain

31
Q

what is the problem with burning fossil fuels

A

Fossil fuels may contain sulfur,
which reacts with oxygen to form
sulfur dioxide.

High concentrations can cause
breathing difficulties, react with
clouds to form acid rain

32
Q

what human activities reduce the
amount of land available for other
animals and plants

A

Quarrying

Crop growing

Farming

building

waste dumping

33
Q

what is Peat

A

Peat is made of plants in waterlogged bogs anaerobic conditions prevent decay.

34
Q

what is peat sold as

A

Peat bogs is sold as compost or fuel.

35
Q

what is the problem with the decay of burning of peat

A

Decay or burning of peat releases carbon dioxide into the atmosphere.

36
Q

what is deforestation.

A

The removal of forest habitat

37
Q

why does Large scale deforestation happen in tropical areas

A

Provide land for farming cattle for food

Provide land to grow crops for producing biofuel

38
Q

what are some biological consequences of global warming

A

Changes in weather which include flooding and drought

Melting of ice caps and increase in sea levels

Habitat loss which can lead to species becoming extinct or critically endangered.

39
Q

how can we Reduce the negative effects of humans on the environment

A

Reintroduction of field margins and hedgerows. Encourages diversity of wildlife as there is a variety of food.

Breeding programmes for
endangered species

Protection and regeneration
of rare habitats.

Reduction of deforestation
and carbon dioxide emissions

Recycling
resources

40
Q

what are Trophic levels

A

Trophic levels are defined as the
feeding levels within an ecosystem.
Trophic levels can be represented by
numbers.

41
Q

what are apex predators

A

Apex predators are carnivores
with no predator.

42
Q

what are Producers

A

organisms which can make their food using sunlight (plants)

43
Q

what are Primary consumers

A

organisms which eat producers (herbivores)

44
Q

what are Secondary consumers

A

organisms which eat primary consumers (carnivores)

45
Q

what are Tertiary consumers

A

organisms which eat secondary consumers (carnivores)

46
Q

what is a herbivore

A

an animal that feeds on plants

47
Q

what is a Carnivore

A

an animal that feeds on other animals

48
Q

what is an omnivore

A

an animal that feeds on plants and animals

49
Q

what is Biomass

A

Biomass is defined as the amount
of living material at each trophic
(feeding) level.

50
Q

Pyramids of biomass can be
constructed to represent what

A

the relative amount of biomass in each
level of a food chain.

51
Q

why are Pyramids of biomass a Pyramid shape

A

because the amount of biomass and
energy available at each trophic level
decreases.

52
Q

what is the formula to Calculate the efficiency of biomass transfer

A

efficiency of biomass transfer = biomass transferred to next level / biomass available at previous level x 100

53
Q

Producers transfer about what % of light energy for photosynthesis.

A

1%

54
Q

what are there losses in biomass as its transferred through each tropic level

A

Not all ingested material (food taken in) is absorbed into the body. Some is egested as faeces.

Not all the absorbed material is used for new biomass. Some is lost as waste (carbon dioxide and water in respiration) and water and urea in urine.

Large amounts of glucose are used up in respiration and provide energy for movement, growth and keeping a constant body temperature.

55
Q

what is Food security

A

having enough food to feed a
population.

56
Q

what factors effect food security

A

Increasing birth rate

Changing diets

New pests and pathogens that affect farming e.g. Bird flu

Environmental changes due to global warming - famine if rains fail as
crops do not grow.

The cost of farming is high

Conflicts in parts of the world which affect the availability of food or
water.

57
Q

describe what happens during intensive farming

A

Animals kept inside so less energy is lost in controlling body temperature

Kept enclosed so less energy required for movement

Both of which mean more energy is available for growth and less energy is
transferred to the environment

Give antibiotics to prevent them getting ill

58
Q

how can the population of fish be maintained

A
  • Regulate net size – larger holes mean smaller fish can escape
  • Impose fishing quotas
  • Limit fishing during breeding seasons
  • Bans on discarding of fish
  • Bans on fishing in certain areas
59
Q

what is biotechnology used for

A

Modern biotechnology techniques enable large quantities of microorganisms to be cultured for food.

60
Q

what is mycoprotein.

A

Mycoprotein is a protein-rich
food suitable for vegetarians.

61
Q

describe how mycoprotein is produced

A

Fungus / Fusarium

Mixed with glucose

in aerobic conditions or in presence of oxygen

mycoprotein is harvested / purified

gcses (19 decks)

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