BIOTECH/V/CC/09 Student's Copy
2 0 1 8
CBCS
5th Semester
BIOTECHNOLOGY
FIFTH PAPER
Molecular Biology
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. Hershey and Chase used radioactive to label DNA of bacteriophages.
phosphorous
nitrogen
sulphur
carbon
2. DNA-binding proteins present in prokaryotes are
H1, HLP-1, H-NS
H1, H2a, HU
HU, HLP-1, H-NS
HLP-1, H3, H4
/154 1 Contd.
3. Semi-conservative DNA replication was first demonstrated in
Escherichia coli
Streptococcus pneumonae
Drosophila melanogaster
Bacteriophage T2
4. Okazaki fragments are joined by
helicase
RNAse
ligase
primase
5. TATAAT box in bacteria is present roughly at position
-10
-35
-21
None of the above
6. TBP stands for
TATA binding protein
Transcription factor binding protein
TFIIB protein
Translation factor binding protein
7. Stop codons that terminate translation are
UAA, UGC, UAC
UAA, UGA, UAG
UGC, UAC, UAG
UGC, UAA, UGA
BIOTECH/V/CC/09/154 2 Contd.
8. Protein degradation is carried out by complexes called
proteasomes
primosomes
nucleosomes
None of the above
9. Proflavin is a/an
ethylating agent
methylating agent
intercalating agent
All of the above
10. Ames test for evaluating the mutagenicity of chemicals was conducted on
Salmonella enteric
Salmonella typhimurium
Salmonella bongori
Salmonella choleraesuis
SECTION—B
Marks 15
Write short notes on the following 3×5=15
1. Plasmids
OR
Histone proteins involved in chromosome packing
2. Significance of C-value paradox
OR
Roles of DNA polymerase III
3. Functions of nuclear transport receptors
OR
Rho-independent transcriptional termination
BIOTECH/V/CC/09/154 3 Contd.
4. General mechanism of protein targeting
OR
Organization of Lac structural genes
5. Differences between spontaneous and induced mutations
OR
Role of oxidative stress in mutation.
PART B—DESCRIPTIVE
Marks 50
The questions are of equal value
1. Write a note on Griffith's transformation experiment.
OR
Explain the experimental evidence to prove that RNA is a genetic material in
viruses.
2. Describe the experiment conducted by Meselson and Stahl.
OR
Mention the different types of DNA polymerases and their functions in
eukaryotes.
3. Explain the steps involved in capping of a pre-mRNA.
OR
Describe the mechanism of transcription in prokaryotes.
4. Describe the regulation of lactose metabolizing proteins in E.coli.
OR
Mention the different types of post-translational modifications and describe any
two.
5. Describe double-strand break repair mechanisms in eukaryotes.
OR
Explain the types of chemical mutagens and their mechanism of action.