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National 5 Biology
Unit 3 Homework
1
Contents
Section 1
Biodiversity And The Distribution Of Life
Homework 1
General Questions
Homework 2
Exam Style Questions
Section 2
Energy In Ecosystems
Homework 3
General Questions
Homework 4
Exam Style Questions
Section 3
Sampling Techniques And Measurement Of Abiotic And Biotic Factors
Homework 5
General Questions
Homework 6
Exam Style Questions
Section 4
Adaptation, Natural Selection And The Evolution Of Species
Homework 7
General Questions
Homework 8
Exam Style Questions
Section 5
Human Impact On The Environment
Homework 9
General Questions
Homework 10
Exam Style Questins
2
Homework 1
1) Give the definitions of the following words:
Ecosystem; Producer; Consumer; Decomposer; Habitat; Population; Niche; Community
[8]
2 a) What does the term Biodiversity mean? Describe how biodiversity impacts
your life.
b) What does the term Abiotic mean? List three Abiotic factors that you can
measure in an environment.
c) What does the term Biotic mean? Lost three Biotic factors that you can
measure in an environment.
d) Explain what ‘pollution’ is and how it affects biodiversity.
e) Describe a key feature of a stable ecosystem.
[2]
[2]
[2]
[3]
[1]
3) List three human activities that have a dramatic impact on named areas of an
ecosystem.
[3]
4) Describe the process of Grazing and it’s impact, both negative and positive, on
biodiversity.
[3]
5 a) Explain what predators and prey are.
b) Describe how predator/ prey interactions affect biodiversity.
[1]
[2]
6a) Explain how changing pH causes a change in biodiversity in marine life.
[1]
b) Explain how changing temperatures causes a change in the distribution of life in
ecosystems.
[2]
7 a) What is a Biome? List three different Biomes found on Earth and briefly describe
them.
[7]
b) Explain how biomes are distributed on Earth in relation to climate zones.
[1]
8) What does the term ‘Ecosystem’ mean? Describe an example of an ecosystem.
[2]
9 a) Describe the term ‘niche’.
b) Name one plant and describe its niche.
c) Name one animal and describe its niche.
[1]
[1]
[1]
[Total 43]
3
Homework 2
1) Read the following passage and answer the questions based on it.
Invasion of the Chinese Mitten Crab
Adapted from Biological Sciences Review, Volume 15, Number 2.
The Chinese mitten crab, Eriocheir sinensis, lives in fresh water as an adult, but it
breeds in the lower reaches of estuaries and spends part of its early life in seawater.
It looks different from other crabs. Its claws are covered in a coating of fine brown
hairs resembling mittens. This type of crab is a problem because it burrows into river
banks, causing them to collapse and silt up river channels.
The mitten crab is not native to Europe. They were recorded in the River Thames in
the 1930s. Their larvae may have been transported to the river in ships’ ballast water
and released during dumping of this water before the ship took on cargo.
Adult mitten crabs have been known to travel thousands of kilometres in freshwater at
up to 18 km per day. The young crabs, when migrating upriver, seem to be mainly
herbivorous. As they grow, they become omnivorous, eating vegetation, crustaceans,
insects and dead fish—in fact anything they can get a hold of! Not only is this a
problem for the plants and animals that they are eating, but also they compete with
native species, such as freshwater crayfish, for food.
(a) How does the appearance of the Chinese mitten crab differ from other crabs? [1]
(b) State the type of environment the Chinese mitten crabs are found in at each of the
following stages in their life.
(i) Early years
(ii) Breeding times
(iii) Mature adults
[1]
(c) How is it thought that the Chinese mitten crabs arrived in Britain?
[1]
(d) Describe one problem the Chinese mitten crab causes to the habitat and one
problem it causes to the native community.
[2]
(e) Describe the changes in its diet as a young adult mitten crab grows.
[1]
(f) When moving at their maximum speed, how long would it take an adult mitten crab
to travel the whole length of a 45 km river?
[1]
4
Q2. Read the passage below and use the information to answer the questions which
follow.
(Adapted from Hostile Habitats, Scottish Mountaineering Trust, 2006).
As you climb a mountain or hill, the vegetation gradually changes. In Scotland, trees
and tall grasses in the glens are replaced on the mountain tops by lichens and dwarf
mosses less than a centimetre high. The treeline is the maximum altitude at which
trees can grow. Scottish hills have relatively little tree cover and so the treeline is not
always obvious but it does form a real ecological boundary. If trees had not been
cleared by humans in past centuries, the slopes below the treeline would be covered in
forest. Low growing vegetation is dominant on the higher
slopes.
The factors which produce the treeline are not clearly understood but the average
temperature during the growing season seems to be important. Under colder
conditions, trees are at a disadvantage compared to low growing, denser vegetation.
The growing tips of trees are fully exposed to high winds which cause physical damage
and slow down growth of shoots by drying them out. High winds in wet conditions cause
wind chill which can further damage shoots. In the case of low growing plants, these
effects are reduced as their growing shoots are protected by the surrounding
vegetation.
The treeline in Scotland is generally lower than in other countries a similar distance
from the equator. The exact height of the treeline varies across Scotland. The wet
and windy conditions in the west of Scotland produce a treeline between 200 m and
450 m above sea level. In the east of Scotland, the treeline is between 500 m and 650
m above sea level. Other types of vegetation show similar effects, with mountain plants
being found at lower levels on the west coast.
(a) Give two types of plants you might expect to find growing on mountain tops in
Scotland.
[1]
(b) Most hills in Scotland do not have woodland present up to the potential treeline.
Why is this?
[1]
(c) According to the passage, what factor might be important in determining how high
up a hill trees can grow?
[1]
(d) What two factors are needed to produce wind-chill?
[1]
(e) The passage states that, “Low growing vegetation is dominant on the higher slopes”.
What advantage does this type of vegetation have which allows it to grow at higher
altitudes than trees?
[1]
(f) In summer, red deer migrate to graze above the treeline. In which part of Scotland
would they have to go higher to do this?
[1]
5
Q3. 1 (a) Link each term with the correct definition.
Term
Definition
Ecosystem
The total number of individuals of one species.
Habitat
The place where an organism lives.
Population
The habitat plus the community.
[3]
Total [16]
6
Homework 3
1 a) Describe what a food chain is.
b) Why are the arrows used in a food chain?
c) What type of organism always goes at the start of a food chain? Why?
d) Write a food chain, with at least 3 stages, that includes you.
[1]
[1]
[2]
[1]
2 a) What is a food web?
b) Why do we use food webs?
[1]
[1]
3 a) Describe what happens to the energy that enters the food chain.
b) Describe how energy is lost from a food chain.
c) Describe how energy is maintained within a food chain?
d) Describe the relationship between the number of organisms in a food chain and
amount of energy available at the end.
[1]
[2]
[1]
the
[1]
4 a) Describe a pyramid of numbers.
[1]
b) Draw an example of a pyramid of numbers.
[1]
c) Explain why a pyramid of numbers is not always appropriate and draw one example.
[2]
5a) What is a pyramid of biomass?
b) What units are used to measure biomass?
c) Is a pyramid of biomass always a ‘true’ pyramid?
[1]
[1]
[1]
6a) What is a pyramid of energy?
b) How is energy measured?
c) Is a pyramid of energy always a ‘true’ pyramid?
[1]
[1]
[1]
7a) What is the Nitrogen cycle and why is it needed?
b) Describe the stages in the nitrogen cycle. You may use a diagram.
c) Name the microorganisms that play a key role in the nitrogen cycle.
d) Describe the occasion whereby nitrogen is released back into the atmosphere.
e) Name an artificial supply of nitrogen to the soil.
[2]
[9]
[2]
[1]
[1]
7
8a) What is competition?
[1]
b) i) List three things that plants compete for
ii) List three things that animals compete for.
[6]
c) What do the terms interspecific and intraspecific mean in terms of competition?[1]
d) What is territory? How do animals claim and defend their territory?
[3]
e) What is the importance of territory?
[1]
Total [49]
8
Homework 4
Q1 . The pictures below show a food chain which is also represented by two types of
pyramid.
Name the type of pyramid X. Explain why both pyramids are correct for this food
chain.
[5]
Q2. a) The diagram shows part of a food web from a forest.
9
(i) The numbers of dormice and owls may be affected if the chaffinches were removed
from the food web.
1 Underline one answer in the brackets and give an explanation.
2 Underline one answer in the brackets and give an explanation.
(ii) Select a food chain from the web which is made up of four stages.
(b) A food chain from the ocean is shown below.
Which population in the food chain has the smallest biomass?
[1]
[1]
[1]
[1]
Q3 The pictures show some organisms from a marine ecosystem. The pictures are not
to scale.
10
The table below shows information about the feeding relationships in the marine
ecosystem.
(a) (i) Use the information in the table to complete the food web below.
[2]
(ii) What term is used to describe the snapper in this ecosystem?
(b) A pod of dolphins arrived in the area. Dolphins feed on snappers.
Describe the effect of the dolphins on the size of the euphausid population.
Explain your answer.
11
[1]
[2]
Q4. The diagram below represents part of the nitrogen cycle.
(a) (i) Use letters from the diagram to identify the following. Each letter may be used
once, more than once or not at all.
Decay of dead material
Nitrification
Nitrogen fixing
(ii) Which type of organism is responsible for process D?
(b) In an investigation, wild rabbits were found to eat an average of 600 g of grass
day. This grass contains 450 g of water. The dry weight of the grass contains 20%
protein. Calculate how much protein a rabbit eats per day.
12
[2]
[1]
per
[1]
Q5. The diagram below represents a food web from a Scottish river ecosystem.
(a)Copy the following table and then decide if each of the statements about this food
web is True or False, and tick the appropriate box. If the statement is False, write
the correct word in the Correction box to replace the word underlined in the
statement.
[3]
b) (i) Make a food chain with four organisms from this food web.
[1]
(ii) What do the arrows in the food chain represent?
[1]
(c) A pyramid of biomass shows the mass of living organisms at each level. Explain why
the heron has the lowest biomass in this food web.
[2]
Total [24]
13
Homework 5
1) a)Describe the two methods of using a quadrat.
b) Give en error that occurs when using a quadrat and how to overcome it.
[2]
[2]
2) a) Describe the following methods of sampling:
Tree-beating
Pitfall trap
Tullgren funnel
Water net
b) What is a Biotic Factor? Give some examples.
c) What is an Abiotic Factor? Give some examples.
d) Refer back to 2a. Are these techniques sampling Biotic or Abiotic factors?
e) What should you do to ensure your results are representative?
[4]
[2]
[2]
[1]
[1]
3a) Draw a labelled diagram of a correctly set up Pitfall trap.
b) Describe two errors that could occur when setting up and using a pitfall trap
and explain how to overcome them.
[4]
4a) Draw a labelled diagram of a Tullgren Funnel.
b) Describe a common error and explain how to overcome it.
[6]
[2]
5) Give a detailed description of the use of a water net. State an error and give
a method to overcome this.
[2]
6a) Draw a labelled diagram of tree beating. Explain a common error and how to
overcome it.
[2]
7a) What is a ‘Biological Key’ and why do we use them?
b) Name the two different types of keys.
c) Describe how to use each of these keys.
[2]
[2]
[4]
[4]
Total [42]
14
Homework 6
Q1. (a) Coal-burning and nuclear power stations are used to produce electricity in
Britain.
Match each type of power station with features considered to be adverse effects of
their operation.
[2]
(b) Environmental protection analysis was carried out on water samples from three
burns.
The Mains Burn had the highest pH at 8.0. It also had the highest oxygen saturation at
94% compared to Bell’s Burn which had the lowest at 65%. The Hatchery Burn had the
lowest value for suspended solids at 4.0 mg/l, with an oxygen saturation of 91.5%. Bell’s
Burn had a suspended solids reading of 5.6 mg/l and the lowest pH at 7.7 compared to
a value of 7.9 for the Hatchery Burn. The highest reading for suspended solids was
recorded in the Mains Burn with a value of 6.0 mg/l.
(i) Draw a table with the data in the passage using suitable column headings.
[3]
(ii) Calcium in the water of the burns raises the pH. Water snails need calcium for shell
growth. Which burn would you expect to have the highest number of water snails [1]
Q2. A study of pollution was made around a coal and steel town in Scotland. A group of
ecologists carried out a survey of lichen at sites on a sample line pointing north-east
from the town. They then repeated the procedure in a south-easterly direction from
the town. The results are given in the graph below.
15
(a) (i) What general conclusion can be made in the relationship between the average
number of species found and the distance from the town centre?
[1]
(ii) How many more species would you expect to find 4 kilometres from the centre of
town on the south-east line compared with the north-east line?
[1]
(iii) Predict the number of species occurring 12 kilometres to the north-east of the
town.
[1]
(b) Give a possible explanation for the difference in abundance of species of lichen on
the two sample lines.
[1]
(c) Why were five counts taken at each site and the average calculated for the number
of lichen species present?
[1]
Q3. An investigation into the effect of soil pH on the distribution of four plant species
W, X, Y and Z was carried out. Soil pH was measured and the average percentage
ground cover of each plant species was recorded in the diagram below.
16
(a) At which pH do the species present give 100 percent ground cover?
[1]
(b) Which of the species can tolerate the widest range of soil pH?
[1]
(c) Which pH allows the growth of the greatest variety of plants?
[1]
(d) From the graph, what evidence is there to suggest that many plants do not tolerate
extremes of pH?
[1]
Total [15]
17
Homework 7
1a) What is meant by the term ‘mutation’?
b) What effect does a mutation in a gene have on:
i) the protein made
ii) The whole organism
c) Explain why a mutation can be harmful or lethal.
d) Explain why a mutation can be beneficial.
[1]
[2]
[2]
[1]
[2]
2) Describe how mutation leads to evolution. Use the terms ‘Survival of the Fittest’,
‘Natural Selection’, and ‘Selection Pressure’.
[4]
3a) What causes a mutation?
b) List some mutagenic agents.
[1]
[3]
4a) What is meant by the term ‘Adaptation’?
b) Explain how an adaptation helps an organism survive.
c) Select one plant and one animal and explain how each is adapted to suit its
environment.
[1]
[2]
5) Describe the process of Natural Selection.
[5]
6a) Define ‘species’.
b) Define ‘speciation’.
c) Describe how a new species is formed.
d) Explain what the Tree of Life is.
[1]
[1]
[5]
[1]
[2]
Total [34]
18
Homework 8
Q1 Give an account of the importance of isolating mechanisms, mutations and
natural selection in the evolution of new species.
[10]
Q2 Write notes on the evolution of new species under the following headings:
(i) the role of isolation and mutation;
(ii) natural selection.
[6]
[4]
Q3. (a) A student set up five petri dishes to investigate the effect of competition on
the
percentage of seedlings surviving after five days. Each dish contained a thin layer of
wet cotton wool with different numbers of seeds placed evenly across its surface, as
shown below.
The table of results for this investigation is shown below.
19
(i) Construct a line graph to show the number of seeds sown against percentage of
seedlings surviving after five days.
[2]
(ii) Name the variable which is altered in this investigation.
[1]
(iii) What conclusion can be drawn from these results?
[1]
(iv) Calculate the simple whole number ratio of the percentage of seedlings surviving in
dish A compared to dish E.
[1]
(v) Another dish was set up with 160 seeds and 88 seedlings survived for five days. [1]
Q4. Darwin discovered that many different species of finch are present on the
Galapagos Islands. The mainland of nearby South America contained only one species of
seed eating finch. The drawings show the evolution of the finch on the Galapagos
Islands together with information on their food sources.
(a) Identify two ways in which the information above illustrates adaptive radiation. [2]
20
(b) Speciation, as illustrated by Darwin’s finches, would involve the events listed in
Table 1. Using the appropriate letters, copy and complete Table 2 to show the correct
order in which the events would occur.
[1]
Total [29]
21
Homework 9
1a) Describe, using a labelled graph, the changes in the human population since 1950.
[4]
b) Explain why the human population has grown this way.
[2]
c) Explain what impact this has had on the Earths resources.
[2]
2a) What is monoculture and what impact does it have on the environment?
[2]
b) Why has deforestation increased and what impact does it have on the
environment?
[2]
c) Describe the process of desertification and explain how dubious farming methods
have contributed to the process.
[3]
3 i) Explain the impact on the environment of overfishing.
ii) Explain the impact on the environment of mass breeding of livestock.
[1]
[1]
4) Explain the term Global Warming.
[3]
5a) What is a fertiliser and what is it used for?
b) Describe one advantage and one disadvantage of using fertilisers.
c) What is a :
i) pesticide?
ii) herbicide?
iii) What are the problems associated with using them?
d) Explain what the chemical DDT is and how it had a massive impact on the
environment.
[2]
[2]
[1]
[1]
[1]
[3]
6a) What is meant by the term ‘Indicator Species’?
[1]
b) Give an example of indicator species for each of the following areas:
i)
freshwater
ii)
air
Include the environmental conditions they report on and describe the effect of the
condition on their distribution
[6]
7a) Describe an alternative to using pesticides.
[2]
b) Describe a method of controlling rabbit populations that does not involve hunting.
[1]
Total [40]
22
Homework 10
Q1. The bar charts below show the mass of domestic waste produced and the
percentage of that waste which was recycled in Scotland from 2001–2008.
23
(a) Calculate the average yearly increase in production of domestic waste between
2001 and 2008.
[1]
(b) (i) Describe the percentage of domestic waste recycled in Scotland from 2001 to
2008.
[2]
(ii) How many million tonnes of domestic waste were recycled in 2006?
[1]
(c) (i) Organic waste can be composted. This helps to recycle plant nutrients
such as nitrates and minerals. Name one other element or compound important for
plant growth, which is recycled during decay processes such as composting.
[1]
(ii) After the manufacture of the compost is complete it may be treated with steam at
120 °C before it is sold. Explain the purpose of this treatment.
[1]
Q2. Boll weevil insects, feed on cotton plants. There are two varieties of cotton plant,
original variety (V) and boll weevil resistant variety (R).
Three farms were used to compare the yield of the two varieties. Each farmer planted
two fields, one of each variety. All fields were treated identically. The yield of cotton
from each field was weighed. The results are shown in the bar graph below.
24
(a) Calculate the average yield of V cotton.
[1]
(b) Calculate the percentage difference in yield between the two varieties of cotton
grown at Farm X.
[1]
(c) (i) Name the variable altered in this investigation.
[1]
(ii) The fields planted with V cotton were used as a control. Give a reason for using this
control.
[1]
(iii) Explain why using ten farms instead of three would have improved this
investigation.
[1]
(d) What conclusion can be drawn from these results?
[1]
(e) The farmers use pesticides to kill insects which damage their crops.
(i) Explain why less pesticide is needed when growing R cotton.
[1]
(ii) Explain why growing R cotton is less likely to affect insect biodiversity.
[1]
Q3. The Peppered moth is found throughout Great Britain. The diagram shows the dark
and light varieties of the Peppered moth.
The table below shows the percentage distribution of each body colour at three
locations.
25
a) In moving from the city to the countryside, state one trend shown in the table. [1]
b) Copy and complete the bar graph using the percentage distribution figures for both
the dark and light moths in unpolluted countryside.
[1]
c) Predict what would happen to the percentage distribution of the light coloured
moths if factories and roads were built in the unpolluted countryside.
(d) Copy out the sentence below, using option in each pair to make it correct.
[1]
[1]
Total [17]
26