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Biology Tutorial Worksheet SB015
1 I KMPK
CHAPTER 7: MUTATION SUBTOPIC : 7.1 and 7.2
7.1 Mutation classification and types
Learning outcomes:
a) Define mutation
b) Classify mutation to i. gene / point mutation ii. chromosomal mutation
c) State two types of mutation: i. Spontaneous mutation ii. induced mutation
d) Define mutagen
e) State types of mutagen: i. physical ii. chemical
7.2 Gene mutation
Learning outcomes:
a) Define gene mutation
b) State and explain four types of gene mutation
c) Explain base substitution
d) Sate the effect of base substitution, base insertion and base deletion
e) Explain base insertion and base deletion as frameshift mutation
7.1 MUTATION CLASSIFICATION AND TYPES (C1)
1.
Class of mutation Type of mutation
1.
2.
1.
2.
2.
BIOLOGY WORKSHEET
Definition of mutation :
Types of mutagen & example Mutagen : Definition
Biology Tutorial Worksheet SB015
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7.2 GENE MUTATION
1. Explain four types of gene mutation (C2)
Based on Figure 1. Complete the table below.
Type of gene
mutation
Description Examples
AAA ATG CTT CTC
AAA ATG TTT CTC
Base insertion
Loses of nucleotide pairs or bases in gene /
DNA
Base invertion
AAA ATG CTT CTC
AAA TAG CTT CTC
Figure 1
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2. Explain base substitution (e.g sickle cell anaemia as missense mutation)
Figure 2 shows 3 types of base substitution.
Figure 2
a) Based on Figure 2 explain the effect of base substitution.
Type of base substitution
Explanation
Missense mutation
Mutation that change____________________________, specifying a different
amino acid. Result :__________________________________________________
Nonsense mutation
Mutation that change________________________________ (UAA, UGA, UAG). Result :____________________________________________________
__________mutation
An alteration in a _____________________________ that does not result in an
amino acid change in a polypeptide.
b) Below is the base sequences for the normal protein for normal hemoglobin and the base
sequences for the sickle cell hemoglobin.
mRNA mRNA
Glu Glu Glu
Missence mutation
Silent mutation
Nonsense mutation
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i) What type of gene mutation above?
___________________________________________________________________________
ii) Transcript and translate the normal and sickle cell DNA.
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
iii) Based on (b) (i) explain the type of gene mutation involves in sickle cell anemia.
___________________________________________________________________________
___________________________________________________________________________
iv) Among symptoms of sickle cell anemia are fatigue, pale and shortness of breath. Explain
why?
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
4. Explain base insertion and base deletion as frameshift mutation (C3)
Figure 3 shows frameshift mutation
Figure 3
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a) State two types of gene mutation that may cause frameshift mutation.
______________________________________________________________________________
______________________________________________________________________________
b) Based on Figure 3 explain frameshift mutation.
______________________________________________________________________________
______________________________________________________________________________
c) Explain why frameshift mutation is said to be harmful?
______________________________________________________________________________
______________________________________________________________________________
Biology Tutorial Worksheet SB015
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CHAPTER 7 : MUTATION SUBTOPIC : 7.3
7.3 Chromosomal mutation
Learning outcomes:
a) Define chromosomal mutation
b) State two types of chromosomal mutation
c) Explain changes in chromosomal structure / chromosomal aberration
d) Define mutagen
e) State types of mutagen: i. physical ii. chemical
7.3: CHROMOSOMAL MUTATION
1. Describe chromosomal mutation.
____________________________________________________________________________
____________________________________________________________________________
2. Complete the organizer below to classify the chromosomal mutation.
3. Complete the table below to show the types of chromosomal mutation
Chromosomal aberration Alterations in Chromosome Number
Explanation:
Explanation:
Chromosomal mutation
aneu 1.
2.
3.
4.
Autosomal
abnormalities
Autoploidy
BIOLOGY WORKSHEET
Aneuploidy
Autopolyploidy
Turner syndrome
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4. Complete the compare-and-contrast table of types of chromosomal aberration
Type Description Examples
ABCDEF ABCEF
Duplication
ABCDEF
Part/segment of a chromosome becomes
oriented in the reverse( turned around 180) of
its usual direction, rearrange the linear gene
sequence.
ABCDEF
Translocation
ABCDEF
5. FIGURES below show the change of chromosome because of mutation. Name each type of
chromosomal aberration shown and explain your answer.
a) ________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
b) ________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
c) ________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
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d) ________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
6. Alteration of chromosomal number occur due to non-disjunction. What is non-disjunction and
when does it occur?
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
7. Draw chromosomes for P,Q,R, S, T and U in the diagram below to show non-disjunction of
sex chromosomes during meiosis.
8. Aneuploidy is a type alteration of chromosome number.
a) What is aneuploidy?
_________________________________________________________________________
_________________________________________________________________________
P Q R
S T U
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b) Explain autosomal abnormalities and their symptoms. Complete the table below.
Autosomal
abnormalities Chromosome Symptom
Monosomy 21
Trisomy 21
(Down syndrome)
c) Explain sex chromosome aneuploids and their symptoms. Complete the table below.
Sex abnormalities Explanation Symptom
Turner
Klinefelter
9. Euploidy / polyploidy is a condition where an individual has more than two sets of
chromosomes. Two types of euploidy are autopolyploidy and allopolyploidy.
a) What is the difference between autopolyploidy and allopolyploidy? How does each arise?
Autopolyploidy Allopolyploidy
Condition
b) Identify the type of euploidy / polyploidy shown below
i)
ii)
Biology Tutorial Worksheet SB015
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TEST YOURSELF
MULTIPLE CHOICE QUESTIONS
7.1 Mutation classification and types
1. Which of the following statement is TRUE about mutation?
A. Mutation can only occur spontaneously
B. Mutation will affect the base sequence of the DNA
C. Mutation does not change the genotype of an individual
D. Mutation can be inherited if it occurs in the somatic cell.
2. Mutation csn occur due to error during
A. Translation
B. Transcription
C. DNA replication
D. Crossing over
3. Those mutations that arise in the absence of known mutagen are known
A. Induced mutations
B. Fused mutations
C. Spontaneous mutations
D. None of the above
4. Which the following mutagens can inhibit spindle formation during cell division?
A. A. Chlorine
B. Colchicines
C. Gamma ray
D. Ultra-violet ray
5. A mutagen is defined as
A. an enzyme that repairs mutations
B. a chemical or physical agent that induces mutations
C. an inhibitor of gene modification
D. a molecule which stabilizes DNA thus prevents mutations from occurring
6. Nondisjunction of sex chromosomes may occur during meiosis I of spermatogenesis. Which
of the following are the possible genotypes of the zygote if the normal ovum is fertilised by
these two types of sperms?
A. XXY and YO B. XXY and YO
C. XYY and YO D. XYY and XO
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7. Which of the following statements regarding mutation is NOT TRUE?
A. Mutations are often beneficial to a population
B. Harmful mutations are prevented from accumulating in a population by natural selection
C. Mutation is a source of variation between individuals as new alleles are produced
D. Dominant mutations are easily detected while recessive mutations remain undetected for
generations
7.2 Gene mutation
The table below shows four types of gene mutation which cause changes in the sequence of
bases in a normal gene.
TACCTTGTCCAT
Normal sequence
of gene bases
TACCTTGGTCCAT Mutation I
TACCATGTCCAT Mutation II
TACCTTGCCAT Mutation III
TACTTCGTCCAT Mutation IV
Below are answers (types of mutations) for questions 8 to 11 :
A. deletion of a base
B. insertion of a base
C. inversion of a base
D. substitution of a base
Which is the type of gene mutation for...?
8. mutation I ( )
9. mutation II ( )
10. mutation III ( )
11. mutation IV ( )
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12. A nonsense mutation
A. usually results in the formation of an abnormally short polypeptide
B. causes one amino acid to be substituted for another in a polypeptide chain
C. is resulted from the deletion of one or two bases, leading to a shift in the reading frame
D. is resulted from the insertion of one or two bases, leading to a shift in the leading frame
13. The insertion of a base pair into the genetic code will cause a frameshift mutation unless the
number of base pairs inserted is
A. one
B. two
C. ten
D. three
14. Figure below shows a type of gene mutation.
What is the type of gene mutation shown?
A. Base deletion
B. Base inversion
C. Base substitution
D. Frameshift mutation
15. In sickle-cell anaemia,
A. Glutamic acid is substituted with valine on the β-polypeptide chain
B. Glutamic acid is substituted with valine on the α-polypeptide chain
C. Valine is substituted with glutamic acid on the β-polypeptide chain
D. Valine is substituted with glutamic acid on the α-polypeptide chain
16. Which the following statement about non-disjunction is FALSE?
A. may produce a polyploidy
B. Turner Syndrome is a result of non-disjunction
C. Non-disjunction only happens during anaphase I meiosis
D. Abnormalities in the number of sex chromosomes and autosomes can happen
17. The effect of a nonsense mutation is a gene by
A. altering the codon of DNA
B. introducing a stop codon into mRNA
C. presenting transcription of mRNA
D. changing the amino acid in the encoded protein
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18. The type of point mutation that usually affects only a single amino acid is called
A. Base deletion
B. Base inversion
C. Base substitution
D. Frameshift mutation
19. The gene arrangement on a chromosome changes from ABCDEF to ABCDEDEF.
This is an example of
A. Deletion C. Inversion
B. Duplication D. Insertion
20. A frameshift is caused by
I. a base substitution
II. a deletion
III. base inversion
IV. base insertion
A. I only C. I and III
B. II only D. II and IV
21. A___________ is one of the DNA mutation that most likely be damaging to the protein they
specifies
A. codon deletion
B. point mutation
C. codon substitution
D. base-pair deletion
22. Which of the following is caused by gene mutation?
A. Cri-du-chat
B. Down syndrome
C. Sickle cell anaemia
D. Klinefelter syndrome
23. Which of the following is caused by deletion of a large part of short arm of chromosome 5?
A. Cri-du-chat
B. Thalassemia
C. Down syndrome
D. Sickle cell anemia
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7.3 Chromosomal mutation
24. Which of the following may result in polyploidy?
A. Translocation
B. Non-disjunction
C. Crossing over
D. Independent assortment of chromosomes
25. Cri- du-chat syndrome is a result of
A. Non-disjunction of the sex chromosome
B. Non-disjunction of the chromosome-21
C. Gene mutation
D. Deletion of the short arm of chromosome-5
26. Which of the following is TRUE about triploids?
A. Usually fertile
B. Cannot undergo meiosis
C. Formed by the fusion of two haploid gametes
D. Triploid occurs when there are less than triploid sets of chromosomes
27. A male with underdeveloped testes and some breast development most likely has
A. Down syndrome
B. Monosomy 21
C. Turner syndrome
D. Klinefelter syndrome
28. Which of the following conditions is NOT an example of a chromosomal mutation?
A. Inversion
B. Duplication
C. Substitution
D. Translocation
29. Chromosomal mutation requires the presence of another chromosome.
A. Inversion
B. Translocation
C. Duplication
D. All of the above
30. Which type of chromosomal mutation occurs when two simultaneous break in a chromosome
lead to the lost of a segment?
A. Inversion
B. Translocation
C. Deletion
D. Duplication
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31. The figure below shows the karyotype of an individual.
What is the correct statement regarding this karyotype?
A. Turner Syndrome
B. Down Syndrome
C. Klinefelter Syndrome
D. Polyploidy
32. Polyploidy refers to
A. multiple ribosomes present on a single mRNA
B. a chromosome which has replicated but not divided
C. an individual with complete extra sets of chromosomes
D. extra copies of a gene adjacent to each other on a chromosome