BIOTECH/IV/EC/07 Student's Copy
2 0 1 8
CBCS
4th Semester
BIOTECHNOLOGY
FOURTH PAPER
Genetics
Full Marks 75
Time 3 hours
PART A—OBJECTIVE
Marks 25
The figures in the margin indicate full marks for the questions
SECTION—A
Marks 10
Tick the correct answer in the brackets provided 1×10=10
1. The character that is expressed in the F1 generation is called the
recessive character
dominant character
co-dominant character
None of the above
2. The phenotypic ratio observed in dominant epistasis is
9 3 4 12 3 1
9 3 3 1 12 2 1
3. The linkage groups in man are
46 23
24 22
/347 1 Contd.
4. Gene A and B are linked genes. Which of the following shows crossing-over
between them?
AB/ab Ab/aB
ab/AB Ab/Ab
5. The pedigree shows
X-linked dominant inheritance
X-linked recessive inheritance
autosomal dominant inheritance
Y-linked inheritance
6. The recombination frequency of is equivalent to
10 mu 20 mu
1 mu 5 mu
7. The transfer of genetic material from one bacterium to another via virus is
called
transformation conjugation
recombination transduction
8. The transposon that does not contain IS elements is
Tn3 Tn5
Tn9 Tn10
9. The chromosome is most condensed during
interphase metaphase
prophase anaphase
10. A condition where individuals have more than two chromosome sets is
known as
euploidy aneuploidy
polyploidy None of the above
BIOTECH/IV/EC/07/347 2 Contd.
SECTION—B
Marks 15
Write short notes on/Answer the following 3×5=15
1. Co-dominance
OR
Multiple alleles
2. Genetic sex determination
OR
If the distance from gene A to gene C is 10 mu, the distance from gene B to
gene C is 43·5 mu and the distance from gene A to gene B is 33·5 mu. Draw
a labeled simple genetic map for genes B and C.
3. Two-point mapping
OR
Physical mapping
4. Specialized transduction
OR
Features of transposition
5. Lampbrush chromosomes
OR
Numerical aberration of chromosomes
PART B—DESCRIPTIVE
Marks 50
The figures in the margin indicate full marks for the questions
1. Explain cytoplasmic inheritance. 10
OR
Explain the experimental evidence provided by Thomas Hunt Morgan to
support the chromosomal theory of inheritance.
2. What are sex-conditioned traits? Give examples to explain the inheritance
pattern of such traits. 10
OR
BIOTECH/IV/EC/07/347 3 Contd.
Describe chromosomal sex determination process observed for heterogametic
males.
3. Mention the mode of inheritance of the given pedigree. Explain in detail the
pattern of inheritance showed by the given trait in each generation 10
OR
Suppose that we carried out a series of two-point crosses for four genes,
c and and obtained the following recombination frequencies
Gene loci in testcross Recombination frequency
a and b 50
a and c 50
a and d 50
b and c 20
b and d 10
c and d 28
Construct a genetic map for these genes by considering the recombination
frequencies for each pair of genes and provide an explanation for the
mapped genes.
4. Describe the mechanism of conjugation in E. coli. 10
OR
Describe in detail the structural features of IS elements and provide a neat
diagrammatic representation of the same.
5. What is chromatin? Describe the different types of chromatins observed in
cells. 10
OR
Write a note on structural variations observed in chromosomes.