biology worksheet chapter 6 : mutation...a. mutation does not change the genotype of an individual...

Biology Tutorial Worksheet DB014

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CHAPTER 6 : MUTATION SUBTOPIC : 6.1 and 6.2

6.1 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

6.2 Gene mutation

Learning outcomes:

a) Define gene mutation

b) Define the four types of gene mutation

c) Describe the consequences of base substitution e.g. sickle cell anaemia

6.1 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


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6.2 GENE MUTATION

1. State the 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 inversion

AAA ATG CTT CTC

AAA TAG CTT CTC

Figure 1


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2. Figure below shows the normal sequence of DNA (template) and mRNA with its translated

amino acid sequence.

3’_ _ _GTG GTC ATG GTG ACT_ _ _5’

5’_ _ _ CAC CAG UAC CAC UGA_ _ _3’

------ His – Gln -- Tyr – His – STOP

Parts of the genetic code table are given below:

(a) What is the amino acid sequence if,

(i) Thymine in the third triplet bases on DNA is substituted with adenine?

(ii) Guanine in the second triplet bases on DNA is substituted with adenine?

(iii) Guanine in the third triplet bases on DNA is substituted with adenine?

(b) Name the type of base substitution in (a)


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3. Figure 4 shows the DNA base sequence for normal hemoglobin and sickle cell hemoglobin.

Figure 4

(a) Define gene mutation. [1 mark]

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(b) Identify the class of gene mutation shown in FIGURE 4. [1 mark]

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(c) State TWO types of mutagens. [2 marks]

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(d) What would be the consequences of mutation in FIGURE 4 in an affected person? [2 marks]

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(e) State TWO classes of gene mutations that could cause frameshift mutation. [2 marks]

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(f) Base substitution mutation introduced a stop codon in DNA base sequence of hemoglobin

gene. What kind of mutation shown by this condition and predict its effect. [2 marks]

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4. Figure 5 shows the normal sequence of an mRNA and its corresponding translated amino

acid.

Figure 5

The mRNA codons for some amino acids are listed below:

(a) What is the sequence of the normal template DNA strand? [1 mark]

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(b) Frequent exposure of the normal gene to radiation can lead to mutation, thus resulting in the

production of a mutant mRNA. What is the amino acid sequence if:

(i) uracil in the fifth codon is replaced by cytosine? [1 mark]

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(ii) guanine in the second codon is deleted? [1 mark]

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(c) State the type of mutation in b(i) and b(ii), and what are their effects.

(i) Mutant b(i): [2 marks]

Type : ___________________________________________________________________

Effect : __________________________________________________________________

(ii) Mutant b(ii) : [2 marks]

Type : ___________________________________________________________________

Effect : __________________________________________________________________


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OBJECTIVE QUESTIONS

1. Which of the following statement is

TRUE about mutation?

A. Mutation does not change the

genotype of an individual

B. Mutation can be inherited if it

occurs in the somatic cell.

C. Mutation can only occur

spontaneously

D. Mutation will affect the base

sequence of the DNA

2. Which of the following is caused by gene

mutation?

A. Down syndrome

B. Sickle cell anaemia

C. Klinefelter syndrome

D. Cri-du-chat

3. The type of point mutation that usually

affects only a single amino acid is called

A. Base deletion

B. Frameshift mutation

C. Base substitution

D. Base inversion

4. Which the following mutagens can inhibit

spindle formation during cell division?

A. Chlorine

B. Colchicines

C. Gamma ray

D. Ultra-violet ray

5. The substitution of a nucleotide is a

A. Translocation

B. Base inversion

C. Point mutation

D. Deletion

6. Sickle cell anaemia is a disease caused by

a point mutation. What is the point

mutation type?

A. Base substitution

B. Nonsense mutation

C. Inversion

D. A and B are correct

7. A mutation involving the changing of one

pair of nucleotide with another pair in a

DNA molecule is called

A. Base substitution

B. Base insertion

C. Base deletion

D. Base inversion


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CHAPTER 6 : MUTATION SUBTOPIC : 6.3

6.3 Chromosomal mutation

Learning outcomes:

a) Define chromosomal mutation

b) State two types of chromosomal mutation

c) Define the four types of gene mutation -base substitution, base insertion, base deletion, base

inversion

d) Describe the consequences of base substitution e.g. sickle cell anaemia

6.3: CHROMOSOMAL MUTATION

1. Describe chromosomal mutation.

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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) ________________________________________________________________________

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b) ________________________________________________________________________

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c) ________________________________________________________________________

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d) ________________________________________________________________________

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6. Draw chromosomes for P,Q,R, S, T and U in the diagram below to show non-disjunction of

sex chromosomes during meiosis.

7. Aneuploidy is a type alteration of chromosome number.

a) What is aneuploidy?

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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

8. 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)


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2. Figure 7 shows karyotype of an abnormal individual.

Figure 7

(a)(i) Name the abnormality of the individual. [1 mark]

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(ii) How does the karyotype differ from a normal person? [1 mark]

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(iii) Give the number of chromosome in sperm cell of the individual in Figure 7 [1 mark]

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(iv) Name the type of chromosomal number alteration in FIGURE 13 and state how it happens.

[2 marks]

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(b) Give TWO common symptoms of monosomy 21. [2 marks]

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(c) (i) Give a common name of trisomy 2l and state how it happens. [2 marks]

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(ii) State the facial characteristic of an individual with trisomy 2l. [1 mark]

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OBJECTIVE QUESTIONS

5. 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

6. Which of the following is TRUE

regarding triploids?

A. Formed by the fusion of two

haploid gametes

B. Usually fertile

C. Occur when there are less than

three sets of chromosomes

D. Cannot undergo meiosis

7. A male with underdeveloped testes and

some breast development most likely has

A. Down syndrome

B. Jacobs syndrome

C. Turner synder

D. Klinefelter syndrome

8. The gene arrangement on a chromosome

changes from ABCDEF to ABCDEDEF.

This is an example of

A. Deletion C. Inversion

B. Duplication D. Insertion

9. Which of the following is caused by

deletion of a large part of short arm of

chromosome 5?

A. Cri-du-chat

B. Down syndrome

C. Sickle cell anemia

D. Thalassemia

10. Which of the following statements is

FALSE regarding a gamete missing one

chromosome?

A. The chromosome number in the

gamete can be expressed as n-1.

B. It occurs because on non-disjunction.

C. When a gamete that is missing one

chromosome fuses with a normal

gamete, the chromosome number of

the zygote can be expressed as 2n-1.

D. This condition is known as euploidy.

11. Which of the following conditions is not

an example of a chromosomal mutation?

A. Inversion

B. Translocation

C. Linkage

D. Duplication

12. Which type of chromosomal mutation

occurs when two simultaneous break in a

chromosome lead to the loss of a

segment?

A. Inversion

B. Translocation

C. Deletion

D. Duplication

biology worksheet chapter 6 : mutation...a. mutation does not change the genotype of an individual...

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