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LSE-03
ASSIGNMENT BOOKLET
Bachelor’s Degree Programme in Science
(B.Sc.)
Genetics (LSE-03)
ASSIGNMENTS 2003
ASSIGNMENT-1 TMA
ASSIGNMENT-2 CMA
SCHOOL OF SCIENCES
Indira Gandhi National Open University
Maidan Garhi
New Delhi – 110 068
LSE-03
Assignments 1 & 2
Year-2003
Dear Student,
As explained in the Programme Guide for B.Sc., you are required to do 2 assignments for the elective course
in Genetics (Course Code: LSE-03). One of the assignments is Tutor-marked (TMA), and the other is
Computer-marked (CMA). The block-wise distribution of assignments is as follows:
Assignment – 1 (TMA) is based on Blocks 1 to 4
Assignment – 2 (CMA) is based on Blocks 1 to 4
The instructions for doing the assignments are given in the Programme Guide under the Section 7.1 –
Assignment. Read the instructions carefully before you start to work on the assignments.
The details regarding assignment submission are given below.
Assignment No.
Assignment – 1 (TMA)
Code: LSE-03/AST-1/TMA-1/2003
Assignment – 2 (CMA)
Code: LSE-03/AST-2/CMA-1/2003
Date of Submission
Where to Send
12 weeks after receiving the
printed material with
assignments.
The Coordinator of your Study Centre.
12 weeks after receiving the
printed material with
assignments.
The Director (SR&E),
Indira Gandhi National Open University,
Maidan Garhi,
New Delhi – 110068.
Some Suggestions:


Submit your assignment-response well in time. Your response received after the due date shall not be
accepted.
Retain a zeroxed copy of your assignment-response for your record.
Best of luck to you.
Course Team
(LSE-03)
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ASSIGNMENT – 1
(TUTOR- MARKED ASSIGNMENT)
Course Code: LSE-03
Assignment Code: LSE-03/AST-1/TMA-1/2003
Maximum Marks: 100
1. “Inspite of compartmentalisation in eukaryotic cell a degree of interdependence or communication exists
between the genetic system present in the cell”. Describe the experimental evidences in support of this
statement.
(5)
2. a) What was Mendel testing when he used a test cross? What procedure did he use and what was the
outcome?
(1+2)
b) How do offsprings from sexual reproduction differ from those produced by asexual
reproduction?
(2)
c) Compare the kind of variations introduced within a species which reproduces sexually with that of a
species which reproduces asexually.
(2)
d) What are sex mosaics? With the help of diagrams only, depict the formation of mosaics due to
mitotic nondisjunction.
(1+2)
3. a) With appropriate examples, discuss the relation between genetics and intelligence.
b) How valid are IQ tests? List the factors influencing the intelligence performance of a child.
4. Write short notes on the following.
a) Deletion mapping
b) Codominance
c) Plant improvement via gene transfer
d) Autoimmune diseases
(5)
(5)
(2½4)
5. Differentiate between the following.
a) Genic and chromosomal sex determination mechanisms
b) Crossing over and translocation
c) Transformation and transduction
d) Positive and negative regulation of gene action
e) Active and passive immunity
(25)
6. A man has royal haemophilia and he married his mother’s sister’s daughter. His maternal grandfather
also had haemophilia. The man and his wife have five children; two daughters are normal, and two sons
and one daughter develop haemophilia. Draw the pedigree.
(5)
7. Write an essay on Genetics of human behaviour.
(10)
8. a) What is the common source for obtaining sample for making chromosome preparation for
cytogenetic studies?
b) What is PHA and from where it is obtained?
c) Why is PHA used in tissue cultures?
d) What does the following human karyotype denote:
(5, del (p14p15)?
e) Is G-banding a stain or a pattern? Explain.
f) Cite two applications of chromosome banding techniques.
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(1)
(2)
(1)
(2)
(1+1)
(2)
9. a) State whether Trisomy-21 is a case of autosomal aneuploidy or sex chromosome aneuploidy ? What
results in this condition?
(1+1)
b) A double stranded DNA molecule consists of 10,000 base pairs. How many nucleotides would it
contain? What would be the number of complete turns in this molecule?
(1+1)
c) What does X-ray diffraction tell us about DNA structure?
(2)
d) In what way is hydrogen bonding important in determining the structure of DNA?
(2)
e) Give one important feature of each of the different conformational forms of DNA.
(2)
10. “Mutations are the effective tools for evolution and can be advantageous to mankind”. Justify the
statement with the help of examples. Limit your answer to about 250 words.
11. Write short notes on oncogenes and retrovirus
(10)
(2½+2½)
12. What is restriction enzyme? Discuss its role in recombinant DNA technique in about 150 words.
(2+3)
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ASSIGNMENT – 2
(COMPUTER-MARKED ASSIGNMENT)
Course Code: LSE-03
Assignment Code: LSE-03/AST-2/CMA-1/2003
Maximum Marks: 100
1. Highly repetitive DNA is found mostly in which region of chromosome?
1) Euchromatic
2) High resolution bands
3) Centromeric
4) Heterochromatic
2. The frequency of an allele in a population can be altered by
1) selection
2) mutation
3) gene migration
4) all of the above
3. Which one of the following does not result in the formation of sex mosaics?
1) mitotic nondisjunction
2) anaphase lag
3) dispermic fertilization
4) parthenogenesis
4. Gene interaction involves interaction of
1) DNA molecules
2) gene products
3) histones
4) palindromes
5. If the nucleotide sequence of one strand of DNA double helix is 5’ – ATAGCAATGCAA-3’, what will
be the sequence of the mRNA strand?
1) 3’-TATCGTTACGTT-5’
2) 3’-TTGCATTGCTAT-5’
3) 5’-UUCCAUUCCUAU-3’
4) 3’-UAUCGUUACGUU-5’
6. Match the items given in Column 1 with those of Column II. Choose the correct answer from the codes
(1 to 4) given below these columns.
Column I
a)
b)
c)
d)
Column II
Cri-du-chat syndrome
Hellin’s Law
Restriction endonucleases
Schizophrenia
i)
ii)
iii)
iv)
frequency of multiple births
polygenic influence
chromosomal structural abnormality
molecular scissors
Codes
1)
2)
3)
4)
a
b
c
d
ii
i
iii
iv
i
iv
i
ii
iv
ii
iv
iii
iii
iii
ii
i.
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7. A child with 47 chromosomes, Brushfield spots in the eyes, an IQ of 40-55, flat facial profile, broad
‘saddle’ nose, short-statured and retarded physical development is a case of
1) Edward Syndrome
2) Patau Syndrome
3) Trisomy X Syndrome
4) Down Syndrome
8. The nest cleaning behaviour of bees is controlled by
1) one gene
2) two genes
3) three genes
4) all the genotypes
9. The genes a, b, c and d lie on the same chromosome of Drosophila. In a series of crosses, the following
recombination frequencies are observed:
Genes
Recombination frequencies
a,b
a,c
a,d
b,d
30%
40%
25%
5%
What is the map distance between b and c?
1)
2)
3)
4)
25 cM
5 cM
40 cM
10 cM
10. Histones are found in
1) eukaryotes only
2) bacteria only
3) viruses only
4) both eukaryotes and bacteria and not in viruses.
11. Which of the following test is used to determine whether two different mutations are within the same
cistron?
1) ClB Test
2) Feulgen Reaction
3) PTC Test
4) Complementation Test
12. What is the order of genes along a chromosome based on the following recombination frequencies?
A-B, 8 map units
A-C, 28 map units
A-D, 25 map units
B-C, 20 map units
B-D, 33 map units
1)
2)
3)
4)
A-B-C-D
B-A-C-D
C-B-D-A
D-A-B-C
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13. Genetic counselling
1) is the process of karyotype analysis of the parents
2) uses recombinant DNA technique to remove a genetic defect
3) aims at dealing with problems related to a genetic disorder in a family
4) is the technique used as a therapy for inherited diseases.
14. One of the following is not a step involved in recombinant DNA technology
1) Cuts made in a DNA molecule with the help of restriction enzymes
2) Joining of DNA fragments with the vector
3) Cloning of hybrid DNA into the host
4) Karyotyping of the host DNA
15. Somatic mutations
1) are sex-linked
2) can never affect the phenotype
3) can be propagated vegetatively
4) end up causing cancerous growth
16. Which of the following statements is incorrect?
1) Detection of mutations in haploids depends on the selection system.
2) Base analogues can bring out mutations by shifting the DNA reading frame.
3) Adjacent pyrimidine bases become linked to one another under the influence of UV rays.
4) Visible light in the blue range can reverse the DNA damage caused by UV rays.
17. TGE
1) can very efficiently repair the DNA damage
2) are the physical mutagens that can alter the hereditary component
3) are the base analogues that can replace a pyrimidine base
4) can break down the reading frame by inserting themselves in the genome.
18. Metastasis
1) is the preneoplastic state of cancer
2) transforms proto-oncogenes into activated form
3) is the invasion of cancerous cells to surrounding tissues
4) is a form of cancer that is induced by radiations only
19. Reverse transcriptase
1) transcribes the DNA of tumor virus into mRNA
2) codes for the protein products of oncogenes
3) is the provirus that integrates into the human chromosome
4) catalyses the transcription of DNA using viral RNA template
20. Hardy-Weinberg principle assumes that in a population
1) mating between male and females is restricted
2) mating between males and females is random
3) individuals of a population multiply by asexual means
4) new individuals enter from outside the population
21. A sex-linked allele cannot be passed from a
1) woman to her daughter
2) man to his grandsons
3) man to his sons
4) woman to the granddaughters
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22. Which of the following male animals is not heterogametic?
1) Drosophila 2n = 6 +XY
2) Pheasant 2n = 14 + XX
3) Grasshopper 2n = 16 + XO
4) Man 2n = 44 + XY
23. In rabbits, black hair (B) is a dominant over white hair (b), and short hair (S) is dominant to long hair (s).
The cross BbSs × bbss results in – 1 black short: 1 black long: 1 white short: 1 white long offspring.
Which of the following crosses would also produce these results?
1) BBSs x bbss
2) Bbss x bbSs
3) Bbss x bbSS
4) BbSs x BbSs
24. How many kinds of gametes are possible with each of the following genotypes: Aa; AaBB; AaBb and
AaBbCc?
1) 2,4,4,6
2) 2,2,2,2
3) 2,2,4,8
4) 2,2,2,4
25. A certain kind of cattle have two genes of coat colour, R for red, and r for white. When an individual
cow is heterozygous, it is spotted with red (roan). When two red genes are present, it is red. When two
white genes are present, it is white. The gene H for lack of horns is dominant over h for the presence of
horns. If a bull and a cow both have the genotype RrHh, how many possible phenotypes of offspring can
they have?
1) 4
2) 6
3) 8
4) 10
26. Which of the following does not contribute to antibody diversity?
1) V-J joining reactions
2) The carbohydrate moeity of antibody molecule
3) Combinational associations
4) Recombination event occurring at the time of V-J joining.
27. Which of the following tools is not used for introducing recombinant DNA into the host cells?
1) Transformation
2) Microprojectiles
3) Electroporation
4) Conjugation
28. Transduction results in recombination of genetic material via the
1) F1 plasmid
2) bacteriophage
3) contact between bacteria
4) acquiring DNA from the medium
29. In a cross between IA IB and IA IO individuals, what would be the genotypes produced? Choose the
correct answer:
1) ½ IA IO : ½ IO IO
2) ¼ 1A 1A : ¼ IA I0 : ¼ 1B1A : ¼ 1B10
3) ½ IA IB : ½ IB IO
4) ½ IA IA : ½ IA IB : ¼ IB IB
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30. A sample of double stranded DNA is analysed and it is found to contain 30%Adenine. What could be
the percentage of Guanine, Thymine and Cytosine in this sample? Choose the correct answer.
Guanine(%)
1)
2)
3)
4)
35
30
20
40
Thymine(%)
15
20
30
10
Cytosine(%)
35
30
20
40
31. What was the tool utilized by Seymour Benzer for constructing the fine structure genetic map of the r II
locus of the phage T4.
1) Homeotic mapping
2) Intragenic mapping
3) Deletion mapping
4) Intergenic mapping
32. Which of the following is not related to crown gall?
1) Monocotyledonous plants
2) Ti plasmid
3) Development of tumors at wounding sites
4) Synthesis of arginine derivative.
33. How many phenotypic classes are produced by a test cross in which one parent is heterozygous for n
pairs of genes?
1) 2n+1
2) 2n-1
3) n2
4) 2n
34. The variable domains of an Igh molecule function as
1) antigen binding sites
2) antigen recognition sites
3) immune response eliciting sites
4) phagocytosing sites
35. Application of colchicine to a vegetative bud of a homozygous tall diploid tomato plant (DD) causes
development of a tetraploid branch. What is the genotype of the somatic cells of this branch?
1) DD
2) DdDd
3) DDDD
4) DDD
36. When lactose is present
i. a repressor is able to bind to the operator
ii. the repressor is unable to bind to the operator
iii. transcription of lac Y, lac Z and lac A genes occurs
iv. the lac operon is repressed
Choose the correct answer from the choices given below
1)
2)
3)
4)
i, iii
ii, iv
ii, iii
i, iv
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37. Match the descriptions X to Z with items i to vi given in the key.
Descriptions
X) Detection of small structural changes in chromosomes
Y) Heterochromatin at any site along the chromosome length
Z) Stimulant for cell division
Key
i)
ii)
iii)
iv)
v)
vi)
Constitutive heterochromatin
Facultative heterochromatin
NOR Banding
Phytohaemagglutinin
High Resolution Banding
Colchicine
Choose the correct answer from the choices given below:
1)
2)
3)
4)
X
iii
iii
v
v
Y
ii
i
i
ii
Z
iv
vi
iv
vi
38. Which one of the following is not matched correctly?
Column I
1)
2)
3)
4)
5)
Induction
Regulation
Regulated gene
Attenuation
Negative regulation
Column II
Gene expression turned on in response to a substance in the environment
Gene expression stopped
Expressed continuously
Controlling gene expression by causing RNA polymerase to terminate
mRNA synthesis hampered until repressor is removed from the DNA of the
gene.
39. Out of the 100 individuals born of a certain genetic disorder, 85 die as a result of the disease within ten
years. Survivors show diverse clinical symptoms from moderate to severe disability. Which one of the
following is true for this disorder?
1) It is due to a dominant gene
2) Its penetrance is 100% and expressivity is variable
3) It has 85% penetrance and 100% expressivity
4) It is caused by quantitative inheritance of a polygenic trait.
40. Sex differentiation occurs in gonads at the
1) time of conception
2) time of birth
3) sixth week of pregnancy
4) none of the above
41. Which one of the following statements pertaining to sex linkage is not true?
1) In species with XX-XY mechanism, genes on the sex chromosomes may be either X-linked or Ylinked.
2) The mode of transmission of sex-linked traits is different from that of the autosomal ones.
3) The dominant X-linked traits are always expressed in both the sexes.
4) All holandric genes are expressed in females.
10
42. Lyonised cells result from
1) inactivation of one X chromosome
2) inactivation of one Y chromosome
3) addition of entire set of a cell’s chromosomes
4) loss of a whole pair of chromosomes
43. Match the items given in column I with those given in column II.
Column I
i)
ii)
iii)
iv)
Column II
Y chromosome
Bipotential embryonal gonad
Cell lines with different genetic constitution
Absence of TDF
1)
2)
3)
4)
(i)
(ii)
(iii)
(iv)
w
x
z
y
x
w
y
z
y
z
w
x
z
y
x
w
w)
x)
y)
z)
Ovaries
Mosaics
Mammalian embryos
Man
44. How many linkage groups are found in the human genome?
1) 2
2) 12
3) 23
4) 46
45. In the chromosome rearrangement known as duplication
1) a fragment of chromosome joins to its homologous chromosome.
2) homologous chromosomes do not separate during meiosis I
3) sister chromatids do not separate during meiosis II
4) a fragment of a chromosome joins to a nonhomologous chromosome
46. The sequence of genes in a chromosome are
123. 45678. The dot(.) represents the position of the centromere. What you have to do is to match the
situations in A to C as given in the key with the descriptions given below
Key
A) 123. 458
B) 123. 47658
C) 12123. 45678
i)
ii)
iii)
iv)
v)
Pericentric inversion
Intercalary deletion
Terminal tandem duplication
Paracentric inversion
Intrachromosomal translocation
Choose the correct answer from the choices given below:
1)
2)
3)
4)
A
B
C
v
iii
i
ii
iii
iv
iii
iv
i
v
v
iii
11
47. What will be the height of offspring having genotype AABBCCdd from parents of medium stature
having genotype Aa Bb Cc Dd?
1) very tall
2) tall
3) medium
4) short
48. Heritability of a trait can range from
1) 1 – 10
2) 0 – 1
3) 1 – 100
4) 1010 – 10
49. According to Hellin’s law the expected frequency of quadruplets birth rate is
1
1)
b
1
2)
b2
1
3)
b3
1
4)
b4
50. If hygenic queen (uurr) is crossed with a nonhygenic drone (uR), what type of drone will be of uurr
genotype?
1) non hygenic
2) remover
3) uncappers
4) hygenic
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INDIRA GANDHI NATIONAL OPEN UNIVERSITY
RESPONSE SHEET FOR COMPUTER MARKED ASSIGNMENT
Enrolment No.
Programme : B.Sc.
Course Code : LSE-03
Assignment Code : LSE-03/AST-2/CMA-1/2003
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