LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – BIOTECHNOLOGY
FIRST SEMESTER – NOVEMBER 2010
BT 1821 - CELL AND MOLECULAR BIOLOGY
Date : 03-11-10
Time : 1:00 - 4:00
Dept. No.
Max. : 100 Marks
PART – A
(20 marks)
ANSWER ALL THE QUESTIONS
1. Choose the correct answer:
( 5 x 1 = 5)
1) What is the size of a microfilament ?
a) 3-6 nm b) 20-25 nm c) 1nm d) 40 nm
2) Identify the eukaryotic initiation codon from the following
a) AGT b) TAG c) ATG d) GAT
3) Heterochromatin is
a) Highly condensed and codes for proteins b) Not condensed and codes for proteins
c) Highly condensed and does not code for protein d) Lightly condensed and codes for protein
4) Receptor is always a
a) Carbohydrate b) Protein
c) Amino acid
d) Lipid
5) MyoD is required for the origin of which cells?
a) Osteoblast b) Hepatocyte c) Muscle d) Cardiac
II. State Whether the following are True or False, if false give reason
(5 x 1 = 5)
6) Crossing over occurs in pachytene stage of Meiosis II.
7) RNA Pol II is involved in t RNA synthesis.
8) Recombination model was first proposed by Watson.
9) cAMP is a second messenger.
10) Number of linkage groups in human male is twenty four.
III. Complete the following:
(5 x 1 = 5)
11) Golgi body is also called as ______ .
12) Transcription occurs in________________ .
13) ___________ genes do not have poly A tails.
14) Electron Transport Chain occurs in ____________.
15) Mendel used _______ as the experimental material .
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IV. Answer the following within 50 words only
16)
17)
18)
19)
20)
(5 x 1 = 5)
What is extracellular matrix?
Define prions.
Why codon bias occur?
Define pinocytosis.
Enlist four alternative terms for extrachromosomal inheritance.
PART – B
(5 x 7= 35 marks)
V. Answer the following, each answer within 350 words;draw diagrams
wherever necessary.
21 (a) Differentiate mitosis from meiosis.
OR
(b) Give an account of cytoskeleton.
22 (a) Mention the various RNA polymerases in eukaryotes and their functions.
OR
(b) Discuss post translational modifications.
23 (a) Distinguish between euchromatin and heterochromatin.
OR
(b) Enumerate the various characteristics of genetic code.
24 (a) Write an account of electron transport chain.
OR
(b) Explain receptor mediated endocytosis with diagrams.
25 (a) Enlist the Mendelian laws and give the genotypic and phenotypic ratios of
monohybrid cross.
OR
(b) What is Linkage and mention its significance? Give the proof of linkage with an example.
PART – C
(3 x 15= 45 marks)
VI. Answer any three of the following, each within 1200 words;draw diagrams
wherever necessary
26. Describe various stages of Meiosis I.
27. Write a detailed note on types of chaperons and protein folding.
28. Explain chromatin organization with diagram.
29. Discuss G-protein linked signal transduction with diagram.
30. Ilustrate Hardy – Weinberg law of equilibrium. What is its significance?
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