Bio3TC17 Mutation QA

Bio3TC17-Mutation-QA

1 Which of the following results in the addition of a single chromosome to the chromosome number of a cell, as in Down’s syndrome? A Chromosome translocation B Nondisjunction C Allopolyploidy D Autopolyploidy

2 During spermatogenesis, a nondisjunction event that occurs during the second division is A better than the first division because only two of the four products of meiosis are aneuploid. B the same outcome as the first division with all four products of meiosis are aneuploid. C the same outcome as the first division as only two products of meiosis are aneuploid. D worse than the first division because all four products of meiosis are aneuploid.

3 Which of the following types of gene mutation cause frame-shift mutation ? I. One base substitution II. One base insertion

III. Two base inversion IV. Deletion of a triplet code A. I, II and III only B. II only C. I and IV only D. II and IV only

4. The diagram below shows a type of mutation that happens in a sequence of nucleotides. C A C G G T A A C A T G G T A A

Which of the following is true regarding the type of mutation shown above? A It is a type of chromosomal mutation. B It can cause frameshift mutation to happen. C It can cause nonsense mutation to happen.

D Sickle cell anaemia is an example of this type of mutation.

5 Part of the amino acid sequences in normal and sickle cell haemoglobin are shown.

normal haemoglobin sickle cell haemoglobin thr-pro-glu-glu thr-pro-val-glu

Possible mRNA codons for these amino acids are glutamine (glu) GAA GAG proline (pro) CCU CCC threonine (thr) ACU ACC valine (val) GUA GUG

Which tRNA molecule is not involved in the formation of this part of the sickle cell haemoglobin?

A B C D

6. The diagram above shows a pair of homologous chromosomes during prophase. What mutation has

occurred?A Deletion B Duplication

C Insertion D Inversion

7. Which of the following could result in polyploidy? I Random segregation II Non-disjunction III Treatment with colchicines IV Hybridisation A. I, II, and III B. I, II, III and IV C. I, II and IV D. II, III and IV

1 TAH

8 Autopolyploid are formed from A the doubling of a hybrid genome from two species B the hybridization of two closely related species C the doubling of the genome within the same species D the non-disjunction that happens to all chromosome pairs

9 The diagram below shows the structure of chromosome which has undergone mutation.

What type of mutation is shown above? A Euploidy B Insertion C Duplication D Translocation

10 The figure below shows normal red blood cells and abnormal red blood cells. The abnormal red blood cells are the symptoms of an inherited blood disorder caused by gene mutation.

(a) What is meant by gene mutation? [1m]

___________________________________________________________________________

(b) State and explain the type of gene mutation which can cause the genetic disorder in (b)? [3m]

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

(c) List the symptoms of an affected person. [2m]

___________________________________________________________________________

___________________________________________________________________________

(d) Give other types of gene mutation. [1m]

___________________________________________________________________________

Normal red blood cell Abnormal red blood cell


11 The table below shows some genetic disorders due to mutation. (a) Complete the table by filling in the specific cause of each disorder. [4m]

Genetic disorder CauseI Sickle cell anaemiaII Klinefelter syndromeIII Cri-du-chat syndromeIV Psychopathic ‘super-male’

(b) What is the main cause of mutation? [1m] _______________________________________________________________________________

(c) Describe briefly each of the following mutation:

(i) Nonsense mutation [1m]

________________________________________________________________________________

________________________________________________________________________________

(ii) Silent mutation [1m]

________________________________________________________________________________

________________________________________________________________________________

12 Illustrate, by means of a genetic diagram, the stages involved in the hybridisation between grasses of

Spartina alterniflora (2n=70) and Spartina stricta (2n = 56) to form a new species Spartina townsendii

(4n=126) [5m]

13. (a) Differentiate between gene mutation and chromosomal mutation. [4m]

(b) Down’s syndrome is caused by chromosomal mutation. Explain how this may occur. [5m]

(c) Describe what is frameshift mutation. [6m]

3 TAH

AA

Answers1B 2A 3B 4D 5A 6D 7D 8B 9D

10a. Change in the base/nucleotide sequence of DNAb. 1. base substitution

2. The CTT triplet nucleotide sequence on DNA changes into CAT / nucleotide with base T is replaced with another nucleotide with base A3. Codon GAA which encodes glutamic acid is substituted with codon GUA which encodes valine4. This change in amino acid results in a mutated β chain of the blood haemoblobinResulting in sickle cell-shaped red blood cells.

c. 1. Insufficient supply of oxygen to various parts of the body2. Physical weakness / fatigue3. Organ damage4. Dizziness

d. Base deletion, insertion, inversion11 (a)

Genetic disorder CauseI Sickle cell anaemia Base substitution of haemoglobin geneII Klinefelter syndrome Non-disjunction leading to a male having an extra of X

chromosomeIII Cri-du-chat syndrome Aberration leading to deletion or loss of a segment of

chromosomal materialIV Psychopathic ‘super-male’ Non-disjunction leading to a male having an extra of Y

chromosome(b) Mutation is caused naturally by changes in environment or can be induced by mutagens e.g

X-radiation and mustard gas (c) (i) Nonsense mutation is a kind of base substitution mutation where the altered codon is stop codon leading to translation of non-functional protein

(ii) Silent mutation is a kind of base substitution mutation where the altered codon is degenerative in nature and still encodes for the same amino acid

12 Illustrate, by means of a genetic diagram, the stages involved in the hybridisation between grasses of Spartina alterniflora (2n=70) and Spartina stricta (2n = 56) to form a new species Spartina townsendii (4n=126) [5m]

P1 : AA X SS (2n=70) (2n=56)

Spartina alterniflora Spartina stricta

G1 : n=35 n=28

F1 : AS 2n=63 Sterile hybrid

Chromosome doubling (caused by

S


Nondisjunction of chromosomes during mitosis or meiosis)

AASS 4n=126Spartina townsendii

13.(a)Gene mutation Chromosomal mutation

Change in the nucleotide sequence in a particular gene;

Change in several genes in the chromosome;

1/0

Small scale alteration; Large scale alteration; 1/0Can sometimes be corrected; Hardly corrected; 1/0Only a slight structural alteration; Are either numerical or structural

changes in the entire DNA strand;1/0

4

.(b) Down syndrome is an example of aneuploidy that is instead of 46 chromosomes there are 47 chromosomes in the individual; it is a result of non-disjunction during meiosis. the two chromosomes number 21 fail to separate during anaphase I or anaphase II of meiosis; the gametes produced contain 24 chromosomes (2 copies of 1 chromosome 21) and 22 chromosomes (no chromosome 21); when a sperm containing 23 chromosomes fuses with an ovum containing 24 chromosomes and the zygote formed contains three chromosome 21, trisomy; the individual may be a male or female usually with flat, broad faces, slanted eyes, short palms and are mentally retarded.

1

11

1

11

.(c) an alteration in the normal reading frame of a gene caused by an insertion or deletion in a DNA sequence; results if the number of inserted or deleted nucleotides is not divisible by three, i.e., the number of nucleotides per codon; DNA sequences are read three nucleotides at a time (codond) and each codon correspond to a specific amino acid or stop signal; during translation, the sequence of codons is read in order to synthesis a polypeptide chain; will alter all the amino acids encoded by the gene following the mutation; proteins synthesised are unable to function properly or at all possibly result in any number of genetic disorders depending on the gene in which the insertion or deletion occurs

1

1

1

111

1

5 TAH

Teacher's copy1 Which of the following results in the addition of a single chromosome to the chromosome number of a cell, as in Down’s syndrome? A Chromosome translocation B Nondisjunction C Allopolyploidy D Autopolyploidy

2 During spermatogenesis, a nondisjunction event that occurs during the second division is A better than the first division because only two of the four products of meiosis are aneuploid. B the same outcome as the first division with all four products of meiosis are aneuploid. C the same outcome as the first division as only two products of meiosis are aneuploid. D worse than the first division because all four products of meiosis are aneuploid.

3 Which of the following types of gene mutation cause frame-shift mutation ? I. One base substitution II. One base insertion

III. Two base inversion IV. Deletion of a triplet code A. I, II and III only B. II only C. I and IV only D. II and IV only

4. The diagram below shows a type of mutation that happens in a sequence of nucleotides. C A C G G T A A C A T G G T A A

Which of the following is true regarding the type of mutation shown above? A It is a type of chromosomal mutation. B It can cause frameshift mutation to happen. C It can cause nonsense mutation to happen.

D Sickle cell anaemia is an example of this type of mutation.

5 Part of the amino acid sequences in normal and sickle cell haemoglobin are shown.

normal haemoglobin sickle cell haemoglobin thr-pro-glu-glu thr-pro-val-glu

Possible mRNA codons for these amino acids are glutamine (glu) GAA GAG proline (pro) CCU CCC threonine (thr) ACU ACC valine (val) GUA GUG

Which tRNA molecule is not involved in the formation of this part of the sickle cell haemoglobin?

A B C D

6. The diagram above shows a pair of homologous chromosomes during prophase. What mutation has

occurred?A Deletion B Duplication

C Insertion D Inversion

7. Which of the following could result in polyploidy? I Random segregation II Non-disjunction


III Treatment with colchicines IV Hybridisation A. I, II, and III B. I, II, III and IV C. I, II and IV D. II, III and IV

8 Autopolyploid are formed from A the doubling of a hybrid genome from two species B the hybridization of two closely related species C the doubling of the genome within the same species D the non-disjunction that happens to all chromosome pairs

9 The diagram below shows the structure of chromosome which has undergone mutation.

What type of mutation is shown above? A Euploidy B Insertion C Duplication D Translocation

10 The figure below shows normal red blood cells and abnormal red blood cells. The abnormal red blood cells are the symptoms of an inherited blood disorder caused by gene mutation.

(a) What is meant by gene mutation? [1m] Change in the base/nucleotide sequence of DNA

(b) State and explain the type of gene mutation which can cause the genetic disorder in (b)? [3m] - base substitution - CTT triplet nucleotide sequence on DNA changes into CAT / nucleotide with base T is replaced with another nucleotide with base A - Codon GAA which encodes glutamic acid is substituted with codon GUA which encodes valine - This change in amino acid results in a mutated β chain of the blood haemoglobin - Resulting in sickle cell-shaped red blood cells.

(c) List the symptoms of an affected person. [2m] - Insufficient supply of oxygen to various parts of the body - Physical weakness / fatigue - Organ damage

7 TAH

Normal red blood cell Abnormal red blood cell

AA

- Dizziness

(d) Give other types of gene mutation. [1m] - Base deletion, insertion, inversion

11 The table below shows some genetic disorders due to mutation. (a) Complete the table by filling in the specific cause of each disorder. [4m]

Genetic disorder CauseI Sickle cell anaemia Base substitution of haemoglobin geneII Klinefelter syndrome Non-disjunction leading to a male having an extra of X

chromosomeIII Cri-du-chat syndrome Aberration leading to deletion or loss of a segment of

chromosomal materialIV Psychopathic ‘super-male’ Non-disjunction leading to a male having an extra of Y

chromosome

(b) What is the main cause of mutation? [1m] Mutation is caused naturally by changes in environment or can be induced by mutagens

e.g X-radiation and mustard gas

(c) Describe briefly each of the following mutation: (i) Nonsense mutation [1m]

Nonsense mutation is a kind of base substitution mutation where the altered codon is stop codon leading to translation of non-functional protein

(ii) Silent mutation [1m] Silent mutation is a kind of base substitution mutation where the altered codon is

degenerative in nature and still encodes for the same amino acid

12 Illustrate, by means of a genetic diagram, the stages involved in the hybridisation between grasses of Spartina alterniflora (2n=70) and Spartina stricta (2n = 56) to form a new species Spartina townsendii (4n=126) [5m]

P1 : AA X SS (2n=70) (2n=56)

Spartina alterniflora Spartina stricta

G1 : n=35 n=28

F1 : AS 2n=63 Sterile hybrid

Chromosome doubling (caused by Nondisjunction of chromosomes during mitosis or meiosis)

AASS 4n=126Spartina townsendii

S


13. (a) Differentiate between gene mutation and chromosomal mutation. [4m]

(b) Down’s syndrome is caused by chromosomal mutation. Explain how this may occur. [5m]

(c) Describe what is frameshift mutation. [6m]

13.(a)Gene mutation Chromosomal mutation

Change in the nucleotide sequence in a particular gene;

Change in several genes in the chromosome;

1/0

Small scale alteration; Large scale alteration; 1/0Can sometimes be corrected; Hardly corrected; 1/0Only a slight structural alteration; Are either numerical or structural

changes in the entire DNA strand;1/0

4

.(b) Down syndrome is an example of aneuploidy that is instead of 46 chromosomes there are 47 chromosomes in the individual; it is a result of non-disjunction during meiosis. the two chromosomes number 21 fail to separate during anaphase I or anaphase II of meiosis; the gametes produced contain 24 chromosomes (2 copies of 1 chromosome 21) and 22 chromosomes (no chromosome 21); when a sperm containing 23 chromosomes fuses with an ovum containing 24 chromosomes and the zygote formed contains three chromosome 21, trisomy; the individual may be a male or female usually with flat, broad faces, slanted eyes, short palms and are mentally retarded.

1

11

1

11

.(c) an alteration in the normal reading frame of a gene caused by an insertion or deletion in a DNA sequence; results if the number of inserted or deleted nucleotides is not divisible by three, i.e., the number of nucleotides per codon; DNA sequences are read three nucleotides at a time (codond) and each codon correspond to a specific amino acid or stop signal; during translation, the sequence of codons is read in order to synthesis a polypeptide chain; will alter all the amino acids encoded by the gene following the mutation; proteins synthesised are unable to function properly or at all possibly result in any number of genetic disorders depending on the gene in which the insertion or deletion occurs

1

1

1

111

1

9 TAH

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Bio3TC17 Mutation QA