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Biology paper 2 (COMPLETE) Flashcards

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Biology 101 flashcards
1
Q

. What is the definition of an ecosystem?

A

The interaction of a community of living organisms with the non ‐living parts of their environment.

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2
Q

What do plants compete with other plants for?

A

Light
Space
Water and mineral ions from the soil

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3
Q

What do animal compete with each other for?

A

Food
Mates
Territory

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4
Q

List two ways a plant may depend on another species for its survival.

A

Pollination

Seed dispersal

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5
Q

What is interdependence?

A

If one species is removed it can affect the whole community

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6
Q

What is meant by a stable community?

A

One where all the species and environmental factors are in balance so that
population sizes remain fairly constant.

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7
Q

What is the definition of an abiotic factor?

A

A non living factor

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8
Q

. List three abiotic factors which can affect an aquatic organism.

A

Oxygen levels
Temperature
Carbon dioxide levels
Light intensity

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9
Q

List three abiotic factors which can affect a plant.

A

Light intensity
Temperature
Carbon dioxide levels
Oxygen levels

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10
Q

What is the definition of a biotic factor?

A

A living factor which may affect a community

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11
Q

List four biotic factors which can affect a community

A

Food availability
A new predator
A new pathogen
One species outcompeting another so that numbers are no longer sufficient to breed

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12
Q

There are three types of adaptation that an organism may show to
aid its survival. What are the three types?

A

Behavioural
Structural
Functional

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13
Q

What is an extremophile?

A

An organism which lives in an extreme environment

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14
Q

Give three examples of what might make an environment be

described as extreme.

A

High temperature
Pressure
Salt concentration

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15
Q

Name

a particular extremophile you have studied

A

Bacteria living in deep sea vents

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16
Q
  1. What is biomass?
A

Amount of living material in an organism

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17
Q
  1. What does a food chain show?
A

Feeding relationships within a community

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18
Q
  1. What do all food chains begin with?
A

A producer

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19
Q
  1. Name two different types of organism which would be found at the start of a food chain.
A

Green plant

Algae

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20
Q
  1. What is meant by the terms mode and median?
A

Mode = number which occurs most often in a set of data.

Median = middle value in a set of dat

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21
Q
  1. What might eat

a secondary consumer?

A

tertiary consumer

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22
Q
  1. Define the term predator.
A

An animal which kills and eats another animal.

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23
Q
  1. Define the term prey.
A

An animal which is hunted and killed for food by a predator

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24
Q
  1. What piece of equipment is usually used to sample abundance of an
    organism in an area?
A

Quadrat

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25
Q
  1. Why is it essential that materials are recycled in the living world?
A

To provide the building blocks for future organisms.

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26
Q
  1. What is precipitation in the water cycle?
A

Rain

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27
Q
  1. List three main processes in the carbon cycle.

Biology Only

A

Photosynthesis
Respiration
Combustion
Decay

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28
Q
  1. Name three factors which must be present for rapid decay of waste
    biological material to occur.
A

Warmth
Oxygen
Water
Microorganisms (Decomposers)

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29
Q
  1. What do gardeners call the end product after waste biological
    material has decayed?
A

Compost

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30
Q
  1. What is this end product then used for?
A

As
a natural fertiliser for
garden plants or crops

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31
Q
  1. What causes anaerobic decay to occur?
A

Insufficient oxygen

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32
Q
  1. Name

a useful end product of anaerobic decay.

A

Methane

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33
Q
  1. What is this product used for? (methane)
A

As

a fuel

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34
Q
  1. What is the name of the equipment used to process and collect this
    end product?
A

A biogas generator

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35
Q
  1. List three environmental changes which may alter the distribution
    of
    a species in an ecosystem.
A

Temperature
Availability of water
Composition of atmospheric gases

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36
Q
  1. Name three reasons why these environmental changes may occur
A

Seasonal
Geographic
Human interaction

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37
Q
  1. Define the term biodiversity?
A

The variety of all the different species or

organisms on Earth or within an ecosystem

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38
Q
  1. What two factors have increased the use of resources by humans?
A

Rapid

growth in population and rise in standards of living

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39
Q
  1. List three categories of pollution caused by human activity.
A

Air
Water
Land

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40
Q
  1. What can cause pollution in each of these three categories?
A

Air: smoke and acidic gases
Water: sewage, fertiliser or toxic chemicals
Land: from landfill and from toxic chemicals

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41
Q
  1. Name four processes which humans carry out that reduces the
    land available to other animals , plants and microorganisms.
A

Building
Quarrying
Dumping waste
Farming

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42
Q
  1. Give three reasons why humans should not destroy peat bogs to
    make compost.
A

Decay of peat releases carbon dioxide into the atmosphere.
Reduces the area of the natural habitat for organisms that live there.
Reduces the diversity of the area as it reduces the number of animals, plants
and microorganisms living there.

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43
Q
  1. What is

a biofuel?

A

A fuel made by living organisms.

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44
Q
  1. Why do humans undertake large scale deforestation in tropical
    areas?
A

To provide land for cattle farming
To provide land for rice fields
To grow crops for biofuels

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45
Q
  1. Name two gases which are increasing in the atmosphere and

contribute to global warming.

A

. Carbon dioxide and methane

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46
Q
  1. List three biological consequences of global warming.
A

Ice caps melting and causing rise in sea levels
Change in climate – droughts and flooding
Loss of habitat and species needing to migrate

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47
Q
  1. Consider the negative aspects of how humans interact with ecosystems. What could be done positively to counteract this effect?

a) global warming and deforestation
b) Animals and plants becoming in danger of
extinction due to reduction in habitat
c) Large 40 acre fields growing one crop
d) dumping waste in landfill sites

A

a) Agreement by governments to reduce
carbon dioxide emissions and
deforestation

b) Introducing breeding programmes
and protection of habitats by
conservation trusts

c) Reintroduce smaller fields and replant
hedgerows and leave edges of field to
grow wild

d) Recycle resources more effectively

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48
Q
  1. Define the term trophic level.
A

Feeding level within an ecosystem

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49
Q
  1. What is a carnivore?
A

Meat eating animal

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50
Q
  1. What is a herbivore?
A

Plant eating animal

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51
Q
  1. What type of consumer is a carnivore which eats another carnivore?
A

Tertiary consumer

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52
Q
  1. What do we call a carnivore that has no predators?
A

Apex predator

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53
Q
  1. What is a decomposer?
A

Microorganisms that break down dead plant and/or

animal matter

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54
Q
  1. How do decomposers gain their food from dead plant or animal matter?
A

By
secreting enzymes into the environment. Small soluble food molecules diffuse
into the microorganism.

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55
Q
  1. What does the pyramid of biomass represent?
A

The relative amounts of biomass
at each level of
a food chain

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56
Q
  1. How much energy as a percentage is transferred by producers from incident light for photosynthesis ?
A

Approximately 1%

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57
Q
  1. Approximately how much biomass, as a percentage, is transferred from a trophic level to the one above it?
A

10%

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58
Q
  1. List two ways in which biomass can be lost at each stage of
    a food chain.
A

Not all ingested food is absorbed
‐ some is lost as faeces.
Not all absorbed food is converted into biomass – some used for keeping
constant body temperature or movement.

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59
Q
  1. What is the equation which should be used to calculate the efficiency of biomass transfer between trophic levels as a percentage?
A

Efficiency of biomass transfer
= biomass transferred to the next level
——————————————————— x100
biomass available at the previous level

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60
Q
  1. What is meant by the term food security?
A

Having enough food to feed

a population

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61
Q
  1. List four biological factors which threaten food security.
A

Increasing birth rate
Changing diets in developed countries leading to food being shipped around
the world
New pests and pathogens affecting farming
Environmental changes
Costs of agricultural inputs
Conflicts which have reduced access to food and water

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62
Q
  1. Give two ways in which energy transfer to the environment can be
    restricted in food animals.
A

Restrict movement

Control the temperature of the surroundings

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63
Q
  1. Some farmers feed their animals high protein food. Why?
A

Increase growth

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64
Q
  1. List two things which can be done to conserve fish stocks in the ocean at
    a sustainable level.
A

Control size of holes in net

Introduce fishing quotas

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65
Q
  1. What type of food does the fungus Fusarium produce?
A

Mycoprotein

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66
Q
  1. How is Fusarium grown?
A

On glucose syrup in aerobic conditions

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67
Q
  1. What is golden rice?
A

Genetically modified rice which has high levels of beta

carotene present

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68
Q
  1. What type of organism produces genetically engineered human insulin?
A

Genetically modified rice which has high levels of beta

carotene present

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69
Q
  1. What is a gamete?
A

A cell with half the number of chromosomes of the parent cell.

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70
Q
  1. Name the male and female gametes in a) a human b) a daisy plant
A

a) Male = sperm Female = egg

b) Male = pollen Female = egg

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71
Q

what happens in meiosis

A

Genetic mixing happens
Gamete production occurs
New cells show variation
Two divisions occur

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72
Q

what happens in mitosis

A

New cells have same no. of chromosomes as parent
Happens in skin cells
Two new cells are formed as a result
Identical cells are formed

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73
Q
  1. How many chromosomes are found in the nucleus of a human:
    a) ovary cell ?
    b) egg cell ?
    c) embryo cell ?
    d) a cell just after fertilisation has occurred?
    e) a testes cell ?
A

a) ovary cell ? 46
b) egg cell ? 23
c) embryo cell ? 46
d) a cell just after fertilisation has occurred? 46
e) a testes cell ? 46

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74
Q
  1. Name the shape which best describes the DNA polymer.
A

Double helix

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75
Q
  1. How is DNA organised inside the cell nucleus?
A

Arranged in chromosomes

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76
Q
  1. Which is larger, a chromosome or a gene?
A

Chromosome

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77
Q
  1. What does a gene code for?

.

A

A particular sequence of amino acids

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78
Q
  1. Write down the definition of the genome of a horse.
A

All the genetic material of the horse.

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79
Q
  1. List two reasons why it is important to understand more about the
    human genome
A

To be able to identify the genes which are linked to different diseases
To understand and be able to treat inherited disorders
To use in tracing human migration patterns from the past

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80
Q
  1. What are three advantages of sexual reproduction?
A

Produce variation in the offspring
If environment changes can give a survival advantage meaning some organisms
are likely to survive
Humans can speed up natural selection by selective breeding to increase food
production

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81
Q
  1. What are three advantages of asexual reproduction?
A

Only one parent needed
More time and energy efficient as do not need to find a mate
Faster than sexual reproduction
Many identical offspring can be produced when conditions are favourable

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82
Q
  1. List three organisms which reproduce using both sexual and asexual reproduction
    methods.
A

Malarial parasites
Fungi
Strawberry plants
Daffodils

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83
Q
  1. Where would you find a nucleotide?
A

DNA

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84
Q
  1. What does a nucleotide consist of?
A

Common sugar, phosphate group, base

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85
Q
  1. What are the symbols of the 4 bases found in DNA?
A

A T C G

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86
Q
  1. What does the code for an amino acid consist of?
A

A sequence of three bases

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87
Q
  1. Fill in the missing terms:
    The long strands of DNA are made of alternating _____ and ______ sections.
    Attached to each
    ______
    is one of the four bases.
    The DNA polymer is made up of repeating ____________ units
A

The long strands of DNA are made of alternating __sugar___ and __phosphate____
sections.
Attached to each __sugar____ is one of the four bases.
The DNA polymer is made up of repeating _____nucleotide_______ units

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88
Q
  1. In the complementary strands of DNA – which base is T always linked to?
A

A

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89
Q
  1. Which organelle in the cytoplasm carries out protein synthesis?
A

Ribosome

90
Q
  1. Which organelle in the cytoplasm carries out protein synthesis?
A

amino caids

91
Q
  1. What do carrier molecules bring to the organelle from the cytoplasm
A

Amino acids

92
Q
  1. What happens in protein synthesis once the protein chain is complete?
A

The protein folds

up into a unique shape

93
Q
  1. What happens if a mutation codes for a slightly altered enzyme protein with a different
    shape?
A

The enzyme may no longer fit the substrate binding site

94
Q
  1. What can non‐coding parts of DNA do?
A

Switch genes on or off and affect how genes are

expressed

95
Q
  1. Complete the sentences below using one of the following words:
    genotype phenotype homozygous gamete chromosome
    The same alleles for a particular characteristic are described as ……………………..
    Mice fur can be described by its colour. This is known as the ………………………….
    The alleles for a particular characteristic determine its ………………………………….
    The pollen of a rose plant can also be described as a male …………………………….
A

The same alleles for a particular characteristic are described as homozygous
Mice fur can be described by its colour. This is known as the phenotype
The alleles for a particular characteristic determine its genotype
The pollen of a rose plant can also be described as a male gamete

96
Q

What are the different forms of a gene called ?

A

alleles

97
Q

Why is it easy to describe an organisms phenotype for a particular characteristic but very
difficult to state the genotype?

A

Most characteristics are a result of multiple genes interacting .

98
Q

. If two heterozygous tall plants were crossed 75 times, what proportion of the offspring
would you expect to be short?

A

25% or 19

99
Q

What is polydactyly and is it caused by inheriting a recessive or dominant allele?

A

A genetic disorder which results in having extra fingers or toes ‐ dominant allele

100
Q

Is someone who is heterozygous for cystic fibrosis healthy?

A

Yes, they are a carrier but do not suffer from CF themselves

101
Q

Many people feel opposed to the screening of embryos to identify the CF allele.
Suggest two reasons why they may feel this way.

A

Screening procedure may cause miscarriage or damage embryo/fetus
The embryo has a right to life
Screening is expensive and could be used for other purposes
Have to make moral/ethical or religious decisions as a result such as whether to
terminate.

102
Q
  1. What does variation mean?
A

Variation means the differences in the characteristics of individuals in a population.

103
Q
  1. Write a definition for evolution.
A

A change in the inherited characteristics of a population over time, through a process
of natural selection.

104
Q
  1. What does the theory of evolution by natural selection state?
A

All species of living things have evolved from simple life forms that first developed
more than 3 billion years ago.

105
Q
  1. What is the definition of the term species?

?

A

A group of similar looking individuals who can breed together and produce fertile
offspring.

106
Q
  1. Humans choose animals or plants to breed from based on usefulness or appearance.
    List four characteristics which would be selected for e.g. a thick woolly coat in sheep
    (two in plants and two in animals).
A

Disease resistance in crop plants
Animals which produce more meat or milk
Domestic dogs with a gentle nature
Large or unusual flowers

107
Q
  1. What is a major disadvantage caused by selective breeding?
A

can lead to inbreeding where some breeds are particularly prone to disease or
inherited defects

108
Q
  1. How often do mutations occur?

t

A

Continuously

109
Q
  1. How likely is it that a mutation will lead to a new phenotype?
A

Very rare

110
Q
  1. What is genetic engineering?
A

A process which involves modifying the genome of an
organism by introducing a gene from another organism to give a desired
characteristic

111
Q
  1. What human product is made by genetically engineered bacteria to treat diabetes?
A

Insulin

112
Q
  1. What are plants called which have had their genome modified?
A

GM crops

113
Q
  1. How are the required genes isolated from the host?
A

Using an enzyme

114
Q
  1. What is the biological definition of a vector ?

14. What is the role of a vector in genetic engineering?

A

Used to insert the gene into the

required cells

115
Q
  1. Name a common vector for inserting genes into the required cells.
A

Bacterial plasmid / virus

116
Q
  1. When in the life cycle must genes be transferred to the cells of animals, plants or
    microorganisms?
A

Early on in development so the new cells develop with the desired
characteristic

117
Q
  1. List three reasons which people are concerned about in relation to genetic engineering
A

Do not know the effect of using GM crops on populations of wild flowers and insects.
may kill insects which are needed to pollinate other plants.
Some people feel that the effects of eating GM crops on human health have not been
fully explored.
For ethical reasons ‐ should humans be inserting genes from one organism into a
totally different organism?

118
Q
  1. What is tissue culture?
A

Using small groups of cells from a part of a plant to grow

identical new plants.

119
Q
  1. Why is tissue culture important?
A

? To preserve rare plant species

Commercially in nurseries to grow lots of new identical plants

120
Q
  1. Why is an electric shock used in adult cell cloning?
A

To stimulate the egg cell to divide

and form an embryo

121
Q
  1. What is the term used to describe the technique gardeners use to produce many
    identical new plants from a parent plant
A

Taking a cutting

122
Q
  1. Name two pieces of evidence for Darwin’s theory of evolution through natural
    selection which mean it is now largely accepted.
A

Fossil record
knowledge of how resistance to antibiotics evolves in bacteria
passing on of characteristics to offspring in genes.

123
Q
  1. What are fossils?
A

The remains of organisms from millions of years ago

124
Q
  1. How are fossils formed?
A

from parts of organisms that have not decayed
when parts of organism are replaced by minerals
as preserved traces like footprints, burrows or rootlets.

125
Q
  1. List two reasons why there are not many traces of early life on Earth.
A

Organisms were mainly soft bodied so little trace left

Any traces destroyed by geological activity

126
Q
  1. What can be learned from studying fossils?
A

how much or how little organisms have changed as life developed on Earth

127
Q
  1. What does an evolutionary tree show?
A

how organisms are related using current classification data or fossil data is a species
is extinct

128
Q
  1. What does it mean when we say an organism is extinct?
A

There are no remaining individuals of a species still alive

129
Q
  1. List four factors which may contribute to the extinction of a species.
A

A change in food availability and the inability to find an alternative source.
Climate change
Creation of a new species by speciation that is better adapted to the environment
Human activity: Road/house building, mining, pollution, poaching, deforestation
A new predator or disease that a species cannot defend itself from.
Failure to breed successfully

130
Q
  1. Why do bacteria evolve rapidly?
A

Because they reproduce at a rapid rat

131
Q

10.Name a bacterial pathogen which is resistant to several strains of antibiotics.

A

MRSA

132
Q

11.Why are pharmaceutical companies not developing new antibiotics ?

A

Very costly

and takes a long time to develop

133
Q

12.Name three things that can be done to reduce the rate of development of
antibiotic resistance.

A

Doctors should not prescribe antibiotics for non serious or viral infections.
Patients must complete the course of antibiotics to ensure all bacteria are killed and
none survive to mutate and become resistant.
Restrict the use of antibiotics in agriculture

134
Q
  1. Name the seven groups that Linnaeus used to classify living organisms.
A

Kingdom, phylum, class, order, family, genus, species.

135
Q
  1. What is the binomial naming system?
A

A method of scientifically naming animals using

the genus and species.

136
Q
  1. Carl Woese used information from chemical analysis to suggest a new method
    of classification. What is it called?
A

The three domain system

137
Q
  1. List the groups that organisms are divided into using Carl Woese’s method.
A

Archaea
Bacteria
Eukaryota

138
Q
  1. What theory did Charles Darwin propose?
A

The theory of evolution by natural selection

139
Q
  1. List three observations Darwin made which led him to propose his
    theory.
A

• Individual organisms within a particular species show a wide range of
variation for a characteristic
• Individuals with characteristics most suited to the environment are more
likely to survive to breed successfully
• The characteristics that have enabled these individuals to survive are then
passed on to the next generation

140
Q
  1. What was Charles Darwin’s book called?
A

On the Origin of Species

141
Q
  1. List three reasons why Charles Darwin’s theory was only partially
    accepted.
A

i. The theory challenged the idea that God made all the animals and plants that
lived on Earth
ii. There was insufficient evidence at the time the theory was published to convince
many scientists.
iii. The mechanism of inheritance and variation was not known until 50 years after
the theory was published

142
Q
  1. Jean Baptiste Lamarck put forward his theory of evolution. What was his
    idea?
A

that changes occur in an organisms life time and these can be inherited.

143
Q
  1. Alfred Wallace also put forward his theory of evolution by natural
    selection independently to Darwin but what work is he best known for?
A

His work on warning colouration in animals and his theory of speciation

144
Q
  1. List the steps needed for a new species to be formed.
A

• Populations of the same species become isolated
• Environmental conditions differ for each population
• Individuals in each population most suited to the environment breed
successfully
• Over time each population will have greater differences in their genotype.
• If two populations of one species become so different in phenotype that they
can no longer interbreed and produce fertile offspring – 2 new species have
been formed.

145
Q
  1. What did Gregor Mendel observe when he carried out breeding
    experiments on pea plants?
A

Inheritance of each characteristic is determined by units that are passed onto
the next generation unchanged.

146
Q
  1. What was discovered in the late 19th century which helped to develop
    our understanding of genetics further?
A

The behaviour of chromosomes in cell division

147
Q

10.When was the structure of DNA determined and the mechanism of
gene function determined?

A

Mid 20th century

148
Q
  1. Define homeostasis.
A

The regulation of the internal conditions of a cell or organism to
maintain optimum conditions.

149
Q
  1. Why does homeostasis need to maintain optimal conditions?
A

For enzyme action and all cell functions

150
Q
  1. List three conditions that the body needs to maintain.
A

Blood glucose concentration, body temperature and water levels.

151
Q
  1. What do the two automatic response systems involve?
A

Nervous responses or chemical responses

152
Q
  1. Define stimuli.
A

Changes in the environment.

153
Q
  1. List the receptor cells and state what stimulus they detect.
A 
Eye (retina) - light, 
Ear – sound, 
Nose – Chemicals in the air, 
Mouth (tongue) – chemicals in food, 
Skin - touch, pressure, pain andtemperature
154
Q
  1. Name the 3 coordination centres in the body and describe what
    each of them coordinates.
A

Brain - coordinates information from the receptor cells and send
signals to the muscles and glands.

Spinal cord - Coordinates messages from the brain and receptor cells
and coordinates reflexes.

Pancreas - coordinates the glucose levels in the blood.

155
Q
  1. What is an effector?
A

A muscle or gland.

156
Q
  1. What is a stimulus?
A

Any change in the surroundings

157
Q
  1. What is a receptor?
A

Cells that detect a change

158
Q
  1. Name the two parts of the central nervous system.
A

Brain and spinal

cord

159
Q
  1. What is an effector?
A

A muscle or gland

160
Q
  1. What does the CNS coordinate?
A

The response of effectors

161
Q
  1. Put these in the correct order: receptor, stimulus, response,
    coordinator, effector.
A

stimulus → receptor → coordinator →

effector → response

162
Q
  1. What is the role of the sensory neurone?
A

Carry impulses from the

receptors to the central nervous system (CNS)

163
Q
  1. What is the role of the relay neurone?
A

Connect the sensory

neurones to the motor neurones in the CNS

164
Q
  1. What is the role of the motor neurone?
A

Connect the sensory

neurones to the motor neurones in the CNS.

165
Q
  1. What is a synapse?
A

A gap between two neurones

166
Q
  1. Describe what happens at the synapse.
A

An impulse reaches the end
of a neurone; neurotransmitter is released across the gap. It then
diffuses across the synapse and when it reaches the next neurone this
starts another impulse

167
Q
  1. Why are reflex actions important?
A

They protect the body from

injury

168
Q
  1. Recall the pathway of the reflex arc
A

. receptor → sensory neurone

→ spinal cord → motor neurone → effector

169
Q
  1. Describe what happens in vasoconstriction and vasodilation
A

• If the body temperature is too low, blood vessels constrict (vasoconstriction),
sweating stops and skeletal muscles contract (shiver).

• If the body temperature is too high, blood vessels dilate (vasodilation) and
sweat is produced from the sweat glands. Both these mechanisms cause a
transfer of energy from the skin to the environment.

170
Q

15.What part of the brain monitors and controls temperature?

A
171
Q

What part of the brain monitors and controls temperature?

A

Thermoregulatory

centre

172
Q
  1. What is the endocrine system composed of?
A

Glands

173
Q
  1. What is a hormone?
A

A chemical that is released from a gland in

response to a change

174
Q
  1. How are hormones carried around the body?
A

In the bloodstream

175
Q
  1. Which acts faster, the nervous system or the endocrine system?
A

The

nervous system

176
Q
  1. Where is the pituitary gland?
A

In the brain

177
Q
  1. What is the role of the pituitary gland?
A

It secretes many hormones in

response to changes in body conditions

178
Q
  1. Name the hormones released by the pituitary gland.
A 
Anti diuretic,
thyroid, 
luteinising, 
follicle stimulating, 
prolactin 
and growth hormone
179
Q
  1. Name the hormones that the pancreas releases
A

Insulin and glucagon

180
Q
  1. What happens to the glucose in the blood when insulin is released?
A

The
glucose is removed from the blood and then converted to glycogen and
stored in the liver and muscles

181
Q
  1. HT: Describe the role of glucagon in the regulation of glucose?
A

Glucagon is released when the blood glucose concentration is low and it
stimulates the liver and muscles to convert glycogen into glucose

182
Q
  1. Which type of diabetes is caused when the body cells no longer
    respond to insulin?
A

Type 2

183
Q

12 . State how Type 1 diabetes is treated.

A

With insulin injections

184
Q
  1. State how Type 2 diabetes is treated
A

By controlling the carbohydrate

in the diet and by exercise.

185
Q
  1. State the ways in which water is lost from the body.
A

Lungs, urine, skin

sweat

186
Q
  1. Sweat contains mostly water. What else can be found in sweat?
A

Ions

and urea

187
Q
  1. What is removed via the kidneys in the urine?
A

Excess water, ions and

urea

188
Q
  1. What is a hypertonic solution?
A

More concentrated solution than in

the cells e.g. concentrated sugar solution

189
Q
  1. What is an isotonic solution?
A

Same concentration as the solution in

the cell

190
Q
  1. What is a hypotonic solution?
A

More dilute than the solution in the

cells. e.g. water or dilute sugar solution

191
Q
  1. What happens to animal cells when they are put in water?
A

Water
enters the cell by osmosis and as the volume increases this puts
pressure on the cell membrane and it bursts. This is called lysis.

192
Q
  1. What happens to animal cells when they are put in a concentrated
    sugar solution?
A

Water leaves the cell by osmosis and the cells shrink and the
membrane wrinkles. This is called crenation

193
Q
  1. HT: What happens to excess proteins in the diet?
A

They are transported

to the liver and converted into urea

194
Q
  1. HT: What does deaminated mean?
A

An amino group is removed from

an amino acid.

195
Q
  1. HT: What is ammonia converted to in the liver?
A

Urea

196
Q
  1. Name the structures in the kidneys where the blood is filtered.
A

Kidney

tubules (nephrons)

197
Q
  1. What are the 3 steps in the blood filtering process?
A

Filtration,

selective reabsorption and excretion

198
Q
  1. Describe what happens in each of the 3 steps of the blood filtering
    process.
A

Filtration of glucose, urea, ions (salts) and water from the blood.

Selective reabsorption of ALL glucose, some ions (salts) and some water
into the blood.

Excretion of ALL urea, excess ions (salts) and excess water
into the urine.

199
Q
  1. HT: Where in the body are the water levels in the blood monitored?
A

The pituitary gland in the brain

200
Q
  1. HT: Name the hormone that controls the water levels in the blood.
A

Anti-diuretic hormone (ADH).

201
Q
  1. HT: What effect does increased levels of this hormone have on the
    kidneys?
A

The kidney tubules to become more permeable to water.

Increased levels of ADH cause the kidneys to re-absorb more water

202
Q
  1. HT: Describe what happens in the body when the water content of
    the blood is too low?
A

The PITUITARY GLAND releases ADH into the blood,
Kidney Tubules MORE permeable and reabsorb MORE water MORE
CONCENTRATED urine is produced and the blood water levels return to
normal

203
Q
  1. HT: Describe what happens in the body when the water content of
    the blood is too high?
A

The PITUITARY GLAND stops releasing ADH into the
blood, Kidney Tubules LESS permeable and reabsorb LESS water LESS
concentrated urine is produced and the blood water levels return to normal

204
Q
  1. How does kidney dialysis treat kidney failure?
A

Filters the blood to restores

the concentrations of dissolved substances in the blood to normal levels

205
Q
  1. Describe how the dialysis machine works.
A

Blood high in urea flows
between partially permeable membranes in the opposite direction to the
dialysis fluid (maintains the concentration gradient).

The dialysis fluid
contains the same concentration of useful substances as the blood - this
ensures that glucose and ions (salts) are not lost.

Urea passes out from the
blood into the dialysis fluid.

206
Q
  1. How does a kidney transplant treat kidney failure?
A

A diseased kidney
is replaced by a healthy donor kidney; this can be from a live donor or
from someone who has died. `

207
Q
  1. State the advantages and disadvantages of kidney dialysis and kidney
    transplants
A

Kidney Dialysis –
Advantages: Available to all kidney patients
(no shortage), no need for immune-suppressant drugs

Disadvantages:
Patient must limit their salt and protein intake between dialysis sessions,
expensive for the NHS, regular dialysis sessions (up to 8hrs) – impacts on
the patient’s lifestyle, risk of infection Kidney

Transplant – Advantages:
Patients can lead a more normal life without having to watch what they
eat and drink, cheaper for the NHS overall

Disadvantages: Must take immune-suppressant drugs which increase the
risk of infection, shortage of organ donors, kidney only lasts 8-9 years on
average, any operation carries risks

208
Q

What is the role of thyroxine?

A

It regulates the metabolic rate, this is

the rate at which energy is released in the body.

209
Q
  1. What is the role of plant hormones?
A

To coordinate and control growth

and responses to light and gravity

210
Q
  1. What is a positive tropism? Give an example of a positive tropism.
A

Where a plant grows towards a stimulus e.g. shoots and light

211
Q
  1. What is a negative tropism? Give an example of a negative tropism.
A

Where a plant grows away from a stimulus e.g. roots and light

212
Q
  1. Where is auxin produced in the shoot?
A

The tip

213
Q
  1. If a light is shining on the side of a shoot, where will the auxin move to?
A
214
Q
  1. What effect does auxin have on the cells in a shoot?
A

They cause cell

elongation

215
Q
  1. Where is auxin produced in the root?
A

The tip

216
Q
  1. What effect do auxins have on the cells in the roots?
A

They stop cell

elongation

217
Q
  1. HT: What is the effect of gibberellins on plants?
A

Involved in growth

and to overcome dormancy in seeds

218
Q
  1. HT: How are gibberellins used in agriculture and horticulture?
A

To end

seed dormancy, promote flowering and increase fruit size

219
Q
  1. HT: What is the effect of ethene on plants?
A

Controls cell division,

promotes flower opening and involved in the dropping of leaves

220
Q
  1. HT: How is ethene used in agriculture and horticulture?
A

Used in the

food industry to control ripening of fruit during storage and transport

221
Q
  1. HT: How are auxins used in agriculture and horticulture?
A

Used as
weed killers, as rooting powders and for promoting growth in tissue
culture.

science by paper (6 decks)

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