Download 2004

ASSIGNMENT BOOKLET
Bachelor’s Degree Programme in Science
(B.Sc.)
Cell Biology (LSE-01)
ASSIGNMENTS 2004
ASSIGNMENT-1 TMA
ASSIGNMENT-2 CMA
SCHOOL OF SCIENCES
Indira Gandhi National Open University
Maidan Garhi
New Delhi – 110 068
LSE-01
LSE-01
Assignments 1 and 2
2004
Dear Students,
As explained in the Programme Guide for B.Sc, you will have to do 2 assignments for the elective course
LSE – 01. One of the assignments is Tutor Marked (TMA) and the other is Computer Marked (CMA). The
blockwise distribution of assignments is as follows:
Assignment – 1 (TMA)
Assignment – 2 (CMA)
Block 1 to 4
Block 1 to 4
The instructions for doing the assignments are provided in the Programme Guide under Section 7.1
Assignment. You should read the instructions carefully before you start doing these assignments.
Please submit your assignments as follows:
Assignment No.
Assignment – 1 (TMA)
Assignment – 2 (CMA)
Date of Submission
12 weeks after receiving the printed
material with assignments.
12 weeks after receiving the printed
material with assignments.
Answer sheets received after the due date shall not be accepted.
We strongly suggest that you retain a copy of your assignments.
Wishing you all good luck.
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Where to Send
The Coordinator of your study centre
The Director (SR&E),
Indira Gandhi National Open
University,
Maidan Garhi,
New Delhi – 110068.
ASSIGNMENT – 1
(Tutor Marked Assignment)
Course Code : B.Sc./LSE-01
Assignment Code : LSE-01/AST-1/TMA-1/2004
Max. Marks : 100
1.
2.
3.
4.
5.
6.
7.
8.
a)
Describe the endosymboint theory regarding origin of organelles in eucaryotes.
(5)
b)
How antibodies can be used for detecting and localizing specific molecules
in the cells?
(5)
a)
State two important differences between animal and plant cells.
(5)
b)
What is the difference between resolving power and magnifying power of a
microscope?
(5)
What are the four major classes of organic molecules of the biosystems? Explain the
structure of the monomer of each of these molecules.
a)
With the help of an example explain the transport across the membrane through a
channel protein.
(10)
(5)
b)
‘Specify with respect to the nature of reaction is one of the basis of mechanism of
enzyme action’. Justify the statement with the help of an example within a limit of
150 words.
(5)
a)
Show the formation of the following bonds :
i) Hydrogen bond
ii) Peptide bond
iii) Glycosidic bond
iv) Phosphodiester bond
v) Ester bond
(5)
b)
Differentiate between concentration gradient and electrochemical gradient.
(5)
a)
Outline the various stages of cellular respiration. Mark the entry molecules(s) and
product(s) of each stage.
(5)
b)
Describe the three major principles of biosynthetic pathways.
(5)
Write notes on the following :
a)
Species-specific aggregation
b)
The role of cAMP as a second messenger
a)
How does a primary transcript differ from a functional mRNA in an eukaryotic cell? (5)
b) Make a list of various events of protein synthesis.
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(5+5)
(5)
9.
a)
List the events of interphase period of cell cycle
b)
Draw a labeled diagram showing the stages of meiosis.
c)
Give 8 points of differences between meiosis and mitosis.
(2+4+4)
10. What is the role of meristematic tissues in plants? Compare the mitotic division in plant
and animal cells.
(5+5)
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ASSIGNMENT – 2
(Computer Marked Assignment)
Course Code : B.Sc./LSE-01
Assignment Code : LSE-01/AST-2/CMA-1/2004
Max. Marks : 100
1.
One of the following is not a characteristic of prokaryotes.
1) Nucleus is absent.
2) Single chromosome is present.
3) Cell wall is made of peptidoglycans.
4) Cell division is mitotic in nature.
2.
You can attribute the ability of a microscope to show the finer details of an object to
1) resolving power
2) magnifying power
3) resolution limit
4) amount of light
3.
Which of the following statements is true?
1) Population of cells obtained from a single cell is called the clone.
2) Resolving power of a microscope is directly proportional to the wavelength of the light.
3) All the cytoplasmic organelles have double membranous structure.
4) Chloroplasts are the energy transducing organelles in eukaryotic cells.
4.
Cells that are actively engaged in synthesis and export of proteins are rich in
1) golgi bodies
2) smooth endoplasmic reticulum
3) rough endoplasmic reticulum
4) glyoxysomes
5.
Which of the following is a disaccharide?
1) Galactose
2) Lactose
3) Ribose
4) Deoxyribose
6.
Based on their charge density macromolecules can be separated by
1) electrophoresis
2) affinity chromatography
3) paper chromatography
4) column chromatography
7.
Which one of the following was observed by scientists when electron microscope was made
available?
1) Chromosome
2) DNA double helix
3) Ribosomes
4) Golgi bodies
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8.
Which one of the following characteristics of a virus places it among living things?
1) made of organic molecules
2) contains RNA or DNA
3) coated with protein
4) can replicate in a living cell
9.
ATP molecule is the energy currency in a cell because it has:
1) the high energy sugar ribose
2) a bond between P and O which breaks and large amount of energy is released
3) very strong covalent bonds
4) ionic bonds among phosphate groups
10. Which one of the following primitive organisms resembles the present day mitochondria?
1) Paracoccus
2) Pleomyxa palustris
3) Protobiont
4) Pythium ultimum
11. The chemotactic signal which induces the aggregation of starved amoeba cells is
1) cycic AMP
2) glycoprotein
3) calcium ion
4) none of the above
12. Which of the following interactions determine the secondary structure of a protein?
a) Hydrogen bonds
b) Disulphide bridges
c) Covalent bonds between amino acids
d) Ionic bonds
Choose the answer from the key given below :
1) a and b
2) a and c
3) b and d
4) c and d
13. Suppose you want to study the core particles of nucleosomes, which one of the following
enzymes you would use to liberate it?
1) Nuclease
2) Protease
3) Polymerase
4) Lyase
14. Which among the following prevent the reunion of the double stand of DNA during DNA
replication?
1) DNA helicases
2) DNA ligase
3) DNA polymerase
4) Helical destabilizing proteins
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15. Which of the following is not differentiated cell?
1) Neurons
2) Skeletal muscle
3) Embryonic cell
4) Red blood cell
16. Match the following proteins secreted in the extracellular matrix with their characteristics
a) Elastin
A)
binds chondrycotes to collagen fibres
b) Laminin
B)
stretches and recoils
c) Fibronectin
C)
binds epithelial cells to collagen
d) Chondronectin
D)
aids in blood clotting
Choose the answer from the code below :
a
b
c
d
1) D
B
A
C
2) B
C
D
A
3) C
A
B
D
4) A
D
C
B
17. Match the following with their functions
a) Gilial cell
b) Dendrons
c) Axon
d)
Schwann cell
A)
B)
C)
D)
support and nourish neurons
receive impulses
transmission of impulse from one
neuron to the next
secrete nylcin sheath
Choose the answer from the code below :
a
b
c
d
1) A
B
C
D
2) B
C
D
A
3) C
D
A
B
4) D
A
B
C
18. Which among the following bone cells release calcium from bone to blood?
1) Osteoblast
2) Osteocytes
3) Osteoclasts
4) None of the above
19. Isoenzymes
1) catalyse the different reactions.
2) are chemically distinct molecules.
3) Differ in kinetic properties for their substrates.
4) Show sigmoidal curve when reaction rate is plotted against substrate concentration.
20. Which of the following is not a technique for the study of metabolic pathway?
1) cell compartmentalisation
2) use of mutants
3) subcellular fractionation
4) use of isotopes
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21. All the carbon atoms of glucose at the end of oxidative metabolism form CO2 during
1) glycolysis.
2) TCA cycle followed by ETC.
3) TCA cycle.
4) glycolysis followed by fermentation.
22. The term degenerate code could refer to
1) the composition of a triplet code by three nucleotides.
2) The genetic code that is associated with specific punctuation signals such as initiation or
termination.
3) a situation where most amino acids are coded by more than one codon.
4) the anticodon located in the third arm of tRNA molecule capable of recognizing a codon
from mRNA.
23. A local chemical mediator is a signaling molecule which acts on target cells present in the
immediate environment. Which of the following is not a local chemical mediator?
1) Prostaglandins
2) Neuroregulators
3) Histamines
4) Neurotransmittors
24. The binding of a signaling molecule to a cell surface receptor may result in
1) receptor mediated endocytosis.
2) activation of adenylate cyclase – cAMP complex.
3) opening or closing gated ion channels in the plasma membrane.
4) all the above
25. In tissues like skin, lungs and blood vessels the external network of fibres present in the
matrix enabling them to recoil after transient stretching contain the protein
1) collagen
2) fibronectin
3) elastin
4) glycosaminoglycans
26. Communicating junctions in cell membranes which allow ions and small molecules to pass
from one interacting cell to another are
1) desmosomes.
2) Gap junctions.
3) tight junctions.
4) none of the above.
27. In plants, the tissue that is structured to give strength to the parts of the body that have
stopped growing is
1) collenchyma.
2) chlorenchyma.
3) sclerenchyma.
4) parenchyma.
8
28. The contractile elements of muscles, actin and myosin are located at
1) sarcolemma
2) sarcoplasm
3) myofibrils
4) sarcoplasmic reticulum
29. Neurons which transmit information from the peripheral parts of the body to central nervous
system are
1) neurosecretory neurons.
2) Sensory neurons.
3) motor neurons.
4) Internuncial neurons.
30. If the sequence of bases in one stand of DNA molecule is TAGGCT then the complementary
sequence of bases in mRNA strand is
1) GTCCAA
2) GCTTAG
3) AUCCGA
4) ATCCGA
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31. The higher levels of chromatin are maintained by histone
1) H1
2) H2A
3) H3
4) H4
32. During RNA synthesis, the DNA template sequence 5’ TpApGpCp-3’ would be transcribed
to produce which of the following RNA sequences
1) 5’-ApTpCpGp-3’
2) 5’-GpCpTpAp-3’
3) 5’-CpGpTpAp-3’
4) 3’-ApUpCpGp-5’
33. The information in ………………….. is translated into protein during translation.
1) DNA
2) m-RNA
3) r-RNA
4) t-RNA
34. The small subunit of a prokaryotic ribosome contains …………………. proteins
1) 19
1) 20
2) 21
3) 22
35. In prokaryotes the P-site and A-sites are located in ………………… subunit of the ribosom
1) 50 S
2) 30 S
3) 60 S
4) 40 S
36. Estradial is
1) water soluble hormone secreted on stimulation by blood glucose level.
2) secreted by exocytosis from mast cells in connective tissues.
3) transported in the blood stream by binding to specific carrier proteins.
4) transported in the cell by binding to cell surface proteins.
37. Target cell adaptation is not caused by
1) unusually high concentrations of small signalling ligands.
2) inactive conformation of receptors caused by prolonged binding of ligands.
3) less number of viable receptors due to higher rate of degradation
4) continuous diffusion of ligands into target cells.
38. Which phase in the cell cycle is marked by the separation of two sister chromatids at their
1) Prophase
2) Metaphase
3) Anaphase
4) Telophase
39. In which cell meiosis occurs?
1) Somatic cell
2) Nerve cell
3) Apical cell
4) Pollen cell
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40. Which one of the following polymers consists of glucose units joined together by only  -14
linkages?
1) Starch
2) Cellulose
3) Glycogen
4) Amylase
41. Match the given processes with their location in the cell.
a) Glycolysis
i)
mitochondrial matrix
b) Synthesis of collagen
ii)
cristae in mitochondria
c) Citric acid cycle
iii)
Cytosol
d) Electron Transfer Chain
iv)
ribosome
Choose the answer from the code below :
a
b
c
d
1) i
ii
iii
iv
2) ii
iii
iv
i
3) iii
iv
i
ii
4) iv
i
ii
iii
42. DNA replication is accurate in forming its complementary copy because of
1) genetic code
2) the base-pairing rules
3) mitosis
4) thymidine nucleotide
43. When glycogen store is depleted in the body, glucose is synthesized from the carbon
skeleton of amino acids, lactate and glycerol. This pathway is called
1) Glyoxylate cycle
2) Glycolysis
3) Gluconeogenesis
4) Glycogenesis
44. Which one of the following is the first event in translation?
1) binding of mRNA to splicosome
2) binding of mRNA to smaller subunit of ribosome
3) attachment of met-tRNA to mRNA
4) joining larger subunit and smaller subunit of ribosomes together
45. The function of tRNA is to
1) provide site for mRNA for protein synthesis.
2) decipher genetic code.
3) transport specific amino acids to protein.
4) form peptide bond.
46. The initiator codon to begin translation of mRNA is AUG; hence the tRNA to join first is
1) leucine tRNA
2) methionine tRNA
3) glycine tRNA
4) any of the above
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47. Match the given processes with their location in the cell.
a) Phase contrast microscopy
i)
image is formed directly as a result of
scattering of electrons.
b) Fluorescence microscopy
ii)
images are distinguished by analyzing
electrons emitted from the specimens.
c) Transmission Electron microscopy
iii)
distinguishes images as a result of
differences in the refractive index.
d) Scanning Electron microscopy
iv)
to observe the molecules that absorb
light at the shorter wavelength and emit
at longer wavelength.
Choose the answer from the code below :
a
b
c
d
1) i
ii
iii
iv
2) ii
i
iv
iii
3) iii
iv
i
ii
4) iv
iii
ii
i
48. Membrane fluidity is determined by the
1) Proteins
2) Carbohydrates
3) Both proteins and carbohydrates
4) Hydrocarbon chains of phospholipids
49. Polar molecules can be transported across the membrane with the help of transport proteins
because these proteins
1) are small in size and move faster across the membrane.
2) are large and stationary across the membranes.
3) create the ion gradient to facilitate the transport.
4) have hydrophobic side chains on their outer surface.
50. Na-+ K+ pump
1) Contrasports Na+ and K+outside the cell
2) Diffuses Na+ and K+ inside the cell
3) Is responsible for generating proton gradient across the membrane
4) Transports Na+ out of cell and K+ into the cell
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