Higher Biology for CfE
Homework
Unit 1 – DNA and the Genome
1.5, 1.6, 1.7 & 1.8
Name:______________________
Class:_________
Teacher:_____________________
1
1.6 Mutations
1. Which of the following is not
an example of a
chromosome structure
mutation?
A. Insertion
B. Duplication
C. Translocation
D. Inversion
2. Which chromosome structure
mutation involves a section of
one chromosome becoming
detached and joined to another
chromosome?
A. deletion
B. duplication
C. inversion
D. translocation
3. The diagram below shows a section of a chromosome and the location of ten
genes.
A mutation during cell division resulted in the following sequence of genes on
the same chromosome.
The type of mutation involved in this example is;
A. deletion
B. translocation
C. duplication
D. inversion
4. Haemophilia B can result from a point mutation in the gene which codes for the protein
required for the clotting of blood.
(a) Name a point mutation and describe how it affects the nucleotide sequence of a
gene.
Name____________________
Description___________________________________________________________
______________________________________________________________(1)
(b) Explain the effect of a point mutation on the structure of the protein produced.
____________________________________________________________________
____________________________________________________________________
_________________________________________________________ (1)
2
5. Sickle cell anaemia is a genetic disorder in which red blood cells contain the protein
haemoglobin S instead of normal haemoglobin. The DNA sequence in the allele for
haemoglobin S carries a mutation.
The table below shows some mRNA codons and the abbreviations for the amino acids
they code for.
mRNA
codon
GUA
CUU
AGA
CAU
UGA
GAA
GGA
Abbreviation for amino acid coded for
val
leu
ser
his
thr
glu
pro
The diagram below shows sections of the DNA sequences that code for normal
haemoglobin and for haemoglobin S.
Section of DNA coding for normal haemoglobin ----ACTCATCCTCCT---Section of DNA coding for haemoglobin S
----ACTCTTCCTCCT----
(a) Use abbreviations from the table to complete the boxes in the diagram below to
show the amino acid sequence of haemoglobin S given.
(1)
(b) Name the type of mutation which has led to the production of haemoglobin S.
_____________________________
(1)
(c) Name bond Y in the diagram which holds amino acids together.
___________________________________________
(1)
(d) Explain why the change in base sequence in haemoglobin S leads to a failure in the
protein to function normally.
______________________________________________________________________
________________________________________________________________(1)
3
6. The diagram below represents stages in the evolution of Triticum aestivum (bread wheat).
The diploid chromosome numbers of some species involved are given.
Which line in the table below indicates correctly the diploid chromosome numbers of
Triticum turgidum and Triticum tauschii?
A
B
C
D
Triticum turgidum
14
28
14
28
Triticum tauschii
14
28
28
14
4
7. Different varieties of banana can have different numbers of chromosome sets in their
cells. Banana flesh contains carotenoids and different varieties have different carotenoid
contents. Extracts of five different varieties of banana were placed in a colorimeter to
measure the transmission of light through them. The darker the flesh the lower the
percentage of light transmitted.
The results are shown in the table below.
Banana variety
Tuugia
Khai
Figo Cinza
Saney
Porp
Number of sets of
chromosomes
2 (diploid)
2 (diploid)
3 (triploid)
3 (triploid)
4 (tetraploid)
Carotenoid content
(mg per kg banana
flesh)
1.6
9.4
2.8
19.2
2.2
Light transmitted
through extract (%)
82
64
72
52
76
(a) Describe the relationship between carotenoid content and darkness of flesh.
___________________________________________________________________
_____________________________________________________________ (1)
(b) (i) Express as the simplest whole number ratio the average carotenoid content of the
diploid to that of the triploid varieties.
Space for calculation
__________:__________ (1)
diploid : triploid
(ii) It has been suggested that additional carotenoid content in the diet gives humans
increased protection against certain cancers.
Calculate the mass of carotenoid which would be found in a 125g sample of Figo
Cinza flesh.
Space for calculation.
____________mg (1)
5
(iii) Using the information given, decide if the statement in the table below is true or false.
Add your choice to the table and give a reason for your answer.
Statement
Banana varieties with increased numbers of chromosome sets
have increased carotenoid content in their cells.
True (T) or
False (F)
Reason
(1)
6
1.7 Evolution
1. The list below shows barriers to gene
exchange which can be important in
speciation.
2. The hooded crow and the carrion crow
can hybridise in parts of Scotland where
both species are found. During an
investigation within the zone of
hybridisation, the numbers of each species
and any hybrids found were estimated at
each of three counting stations.
1. Behavioural
2. Geographical
3. Ecological
Which line in the table below correctly
matches the barriers with the type of
speciation in which they are involved?
A
B
C
D
Counting
station
1
2
3
Type of speciation
Sympatric
Allopatric
1 and 3
2 only
1 and 2
3 only
2 only
1 and 3
1 only
2 and 3
Hooded
90
40
40
Crows
Carrion
70
30
10
Hybrid
40
30
50
What percentage of the crows at counting
station 1 were hybrids?
A.
B.
C.
D.
10%
20%
25%
40%
3. Haemophilia B is a genetically inherited condition in humans which affects a protein required
for blood clotting. The information below shows the inheritance of this condition in a family in
which some of the individual are affected by haemophilia B.
Parents
Offspring
unaffected father
x
homozygous affected mother
two affected males and one unaffected female
State why the pattern of inheritance shown above is described as vertical
___________________________________________________________________________
_____________________________________________________________________ (1)
7
4. Genetic drift is a change in gene
frequency, particularly in small populations.
5. Which of the following is true of genetic drift?
Which of the following is true of genetic
drift?
B. It is predictable in its action.
A. It is random and influenced by the
founder effect.
B. It is non-random and is influenced by
the founder effect.
C. It is random and influenced by natural
selection.
D. It is non-random and influenced by
natural selection.
A. It acts in a random way
C. Its effect is greater in large populations
D. It involves survival of the fittest
6. Mytilis edulis and Mytilus trossulus are two closely related species of mussel which have
evolved after populations of their common ancestor became separated by a geographical
barrier.
(a) Name the type of speciation involved in this case.
________________________________________________________________
(1)
(b) Describe the evidence needed to confirm that M. edulis and M. trossulus are different
species
_________________________________________________________________________
______________________________________________________________________ (1)
(c) Regions have been discovered in which the two closely related species occur together and
sometimes interbreed.
What name is given to these regions?
______________________________________________________________
(1)
8
Questions 7 and 8 refer to the following information.
The graphs below show the effects of natural selection pressure on wing span in a population
of house sparrows between 1930 and 1980.
7. Which line in the table below correctly compares the statistical data in the two graphs?
A
B
C
D
Mean
same
same
different
different
Range
same
different
same
different
8. Which line in the table below correctly describes the change in gene frequency and the type
of selection involved in this case?
A
B
C
D
Change in
gene
frequency
non-random
random
non-random
random
Type of selection
stabilising
directional
directional
stabilising
9
9. Three species of Penstemon plants have evolved side by side in the same areas of North
America through speciation from a common ancestor.
Each species has specialised pollinators adapted to reach nectar found in nectaries inside their
flower tubes, close to the base.
(a) (i) From the information given above, explain how interbreeding between the three
species of Penstemon is prevented.
____________________________________________________________________
____________________________________________________________________
_________________________________________________________________ (1)
(ii) Name the type of speciation which has resulted in the evolution of the three species
of Penstemon.
____________________________________________________________
(1)
(iii) Describe the evidence which could confirm that these plants are different species.
____________________________________________________________________
_________________________________________________________________ (1)
(b) Underline one word in each pair to make the sentences correct.
Flowering plants are {eukaryotic / prokaryotic} and pass on their genetic sequences
{vertically / horizontally}. The type of reproduction in flowering plants which gives the
greatest potential to produce variety in the offspring is {asexual / sexual}
(2)
10
Questions 10 and 11 refer to the information and the graph below.
In Ecuador, populations of two species of butterfly, Heloconius erato and Heliconius himera,
overlap and form a zone in which hybrid individuals are found.
Butterflies were collected from sites along a line extending north and south from a central point
close to the middle of the hybrid zone. Each butterfly was scored on a scale from 0.0-1.0.
A score from 0.0 is pure H. erato and a score of 1.0 is pure H. himera. Values in-between are
hybrids.
The results are shown in the graph below.
10. How wide is the zone in which hybrids were found?
A. 5.0km
B. 7.5km
C. 10.0km
D 12.5km
11. Which line in the table below shows correctly the distance and direction of a site at which
hybrids with a score of 0.25 would be expected?
A
B
C
D
Distance (km)
2.5
5.0
1.0
7.5
Direction
south
south
north
north
11
1.8 Genomic Sequencing
1. The following list gives descriptions of three areas of study which use genomic
sequencing.
X study of evolutionary relatedness
Y study of comparative gene sequences using computers and statistics
Z study of genomics related to personalised medicine
Which line in the table below correctly matches the name of the area of study with their
descriptions?
A
B
C
D
Area of study
Bioinformatics Pharmacogenetics Phylogenetics
Y
Z
X
Y
X
Z
Z
Y
X
X
Z
Y
Questions 2 and 3 refer to the following information
Protein fingerprinting is a technique used to compare proteins from different species.
Species which are closely related have similar protein fingerprints.
Samples of proteins are extracted from cells, separated by gel electrophoresis, then stained
to make each type of protein show up as a band. The smaller the protein molecules, the
further they travel through the gel.
The diagram below shows protein fingerprints for four different species.
2. Which species contains protein with the smallest molecules?
A. 1, 3 and 4 only
B. 2 only
C. 4 only
D. 1, 2 and 3 only
3. Which two species shows the greatest difference in their protein fingerprint?
A. 1 and 4
B. 1 and 2
C. 1 and 3
D.3 and 4
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4. The diagram below shows the divergence of lineages in the evolution of the giant panda and
related species which exist today.
(a) Give two sources of evidence that can provide information used to produce diagrams of
this type.
1._____________________________________________________________
2._____________________________________________________________ (2)
(b) State how long ago the last common ancestor of the giant panda and polar bear existed
____________ million years before present (1)
(c) State the number of other species with which the sun bear shared a common ancestor
eight million years before present.
______________ species
(1)
(d) Evidence has suggested the existence of three main domains of life.
Name the three main domains of life.
1. __________________________________
2. __________________________________
3. __________________________________
(2)
13
Extended Response Questions
KA 1.1

Describe the function of DNA and give an account of the structure of a DNA molecule. (7)
KA 1.2

Give an account of the replication of a molecule of DNA. (7)
KA 1.3

Give an account of gene expression in eukaryotic cells under the following headings:
(a) Transcription of DNA
(4)
(b) Translation of mature mRNA
(4)
KA1.4.

Write notes on stem cells under the following headings:
(a) Differentiation of stem cells (7)
(b) Research into stem cells and their therapeutic value (3)

Give an account of the process of cellular differentiation in animals and the function of
meristems in plants. (4)

Give an account of ethical issues related to stem cell use. (4)
KA 1.6

Name and describe the types of structural mutation of chromosomes. (4)

Give an account of duplication and polyploidy and their importance in evolution. (6)
14
KA 1.7

One type of selection pressure is stabilising selection. Give an account of this type of
selection pressure and the names and effects of two other types of selection pressure on
populations (5)

Give an account of the role of natural selection in evolution (5)

Give an account of the formation and maintenance of zones of hybridisation (4)
KA 1.8

Give an account of phylogenetics and molecular clocks. (6)
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