ASSIGNMENT BOOKLET
Bachelor’s Degree Programme in Science
(B.Sc.)
Cell Biology (LSE-01)
ASSIGNMENTS 2003
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
2003
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.
2
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-1/2003
Max. Marks : 100
1.
a)
b)
i) Explain three protobiont models.
ii) State two important differences between animal and plant cells.
Explain the possible evolutionary mechanism by which photosynthesis developed from
the early anaerobic and heterotrophic bacteria.
(1½+1+2½)
Compare phase contrast microscopy with fluorescence microscopy?
How antibodies can be used to detect and localize specific molecules in the cell?
(2½×2)
Explain polymorphism in lysosomes with suitable diagram.
i) What is the function of glyoxysomes?
ii) How do peroxisomes play a role in detoxification?
(2½ +1+1½)
2.
a)
b)
3.
a)
b)
4.
a)
b)
Explain ionization property of water.
How is ionic product of water (Kw) calculated?
a)
b)
What are lipids?
Differentiate between compound lipids and derived lipids.
5.
6.
7.
Write short notes on
i) membrane proteins
ii) membrane carbohydrates
a)
b)
(2½×2)
(2+3)
(2½×2)
Differentiate between the following terms.
i) Simple diffusion and facilitated diffusion
ii) Turgor pressure and osmotic pressure
Why osmosis is considered as a special case of diffusion?
(1½+1½+2)
8.
With the help of an example explain how ion gradient aids in the active transport of some
molecules into cell.
(5)
9.
a)
b)
What are enzymes?
Describe the Operon model to regulate the enzyme activity.
10. Differentiate between the following:
a) Anabolic and catabolic pathways
b) Substrate level phosphorylation and oxidative phosphorylation
11. What is the importance of pentose phosphate pathway?
12. a)
b)
c)
List the three stages of transcription.
Write two differences between procaryotic and eucaryotic transcription.
State the location of three RNA polymereses.
3
(2+8)
(2½×2)
(5)
(1½+2+1½)
13. a)
b)
List the steps involved in the synthesis of a peptide chain in a prokaryote.
List six post-translational modifications in a protein.
14. Differentiate between the following terms.
i) Hormones and neurotransmitters
ii) Mitosis and meiosis
(2+3)
(2½×2)
15. Discuss the significance of the process of crossing over for living beings.
(5)
16. Explain the process of species specific aggregation with the help of an example.
(5)
17. a)
b)
Compare between smooth muscles and cardiac muscles.
Briefly describe the types of cartilage present in animals.
18. Describe the organisation of the major chemical components of plant cell wall.
4
(2½×2)
(10)
ASSIGNMENT – 2
(Computer Marked Assignment)
Course Code : B.Sc./LSE-01
Assignment Code : LSE-01/AST-2/CMA-1/2003
Max. Marks : 100
1.
Which of the following organelles are present in procayotes?
1) Mitochandria
2) Chloroplast
3) Ribosomes
4) Lysosomes
2.
Bacteriophage is a specific type of
1) bacteria
2) protozoa
3) eukaryote
4) virus
3.
35
S radioisotope is used as a tracer of
1) salt metabolism
2) nucleic acid metabolism
3) phospholipid metabolism
4) protein metabolism
4.
If you want to examine the patterns of capillaries in a section of skin, which microscope will
you use?
1) LM
2) TEM
3) SEM
4) Phase contrast microscope
5.
Periodic Acid Schiff (PAS) is used to stain which of the following chemical component of
the cell?
1) Lipids
2) Proteins
3) Nucleic acids
4) Polysaccharides
6.
Which from of lysosomes are found in abundance during pathological conditions?
1) Primary lysosomes
2) Secondary lysosomes
3) Residual bodies
4) Autophagic vacuoles
7.
Which of the following organelles does not constitute cytoskeletal system?
1) Cilia
2) Flagella
3) Chloroplast
4) Basal Bodies
5
8.
A cell with extensive network of RER is activity involved in
1) lipid metabolism
2) protein synthesis
3) formation of cell plate
4) ATP production
9.
The alpha carbon atom in each amino acid is attached to
1) a carboxyl group, an amino group and a side chain
2) a sugar, a phosphate and an amino group
3) a keto group and two carbon atoms
4) carbon, hydrogen and oxygen atoms in the ratio of 1:2:1
10. SDS polyacrylamide gel electrophoresis is used when biomolecules are separated on the
basis of their
1) size
2) affinity
3) solubility
4) total charge
11. Peptide bonds responsible for the formation of protein polymers are
1) hydrophobic bonds
2) covalent bonds
3) Vander wal forces
4) electrostatic bonds
12. The most important storage polysaccharides in the plants and animals are
1) starch and glycogen
2) cholesterols
3) terpenes
4) chitin
13. The lipids that contain no fatty acids are
1) neutral fats
2) phospholipids
3) steroids
4) sphingolipids
14. Fimbrin
1) helps actin filaments to slide against myosin
2) is a cross linking protein than binds actin filaments
3) is a protein that helps in polymerization of globular actin
4) is a cross linking protein that binds actin with myosin
15. All cell membranes are constructed as lipid bilayer because
1) glycolipids and glycoproteins are found on the non-cytoplasmic side of the membrane
2) membrane proteins are amphipathic and their hydrophilic regions are exposed to water
on both sides
3) membrane cholesterol prevents the hydrocarbon chains of membrane lipids to bind
4) membrane lipids are mainly phospholipids and all the phospholipids are amphipathic in
nature
6
16. A solution having higher osmotic pressure than the other is called as
1) hypo-osmotic
2) hypotonic
3) hyperosmotic
4) iso-osmotic
17. Which of the following quantitative factors does not control the movement of substances
across the membrane
1) driving force
2) flux
3) permeability
4) diffusion
18. In equation P = D/d, P is called as
1) flux
2) concentration difference
3) permeability coefficient
4) diffusion coefficient
19. Most of the transport molecules are transmembrane
1) sugars
2) lipids
3) proteins
4) amino acid
20. Which of the following statements is true?
1) The activity of Na+ K+ ATPase is inhibited by phlorrizin which binds to its active site.
2) In chloroplasts ATP is synthesized by the efflux of protons accumulated inside of the
thylakoid membrane.
3) Gramicidin molecules are mobile ionophores which can be used as antibiotics.
4) The channel protein that transports CO2 across the RBC membrane is transmembrane protein.
21. Activation energy
1) is derived from ATP
2) binds the cofactors to enzyme protein
3) breaks the energy barrier to start a reaction
4) helps in energy transduction
22. Which of the following is not true?
1) Binding of reaction molecules with each other brings them in close proximity.
2) Acidic and basic amino acids in the active site transfer the protons for the catalysis of
the reaction.
3) Hydrophobic amino acids eliminate water from the active site to facilitate the catalysis.
4) Enzymes react with the substrate to from high energy, stable enzyme-substrate complex
23. Km
1)
2)
3)
4)
is the saturation point where maximum velocity of the reaction is attained
depends on the concentration of the enzyme to form enzyme – substrate complex
brings the reaction system to a steady state
is the substrate concentration where half the enzyme molecules are saturated with
substrate molecules.
7
24. Activation of trypsinogen into trypsin is brought about by
1) covalent modulation
2) hormone action
3) complexing with calmodulin
4) allosteric regulation
25. Which of the following is not used for the study of metabolic pathways?
1) Subcellular fraction
2) Tissue slices
3) Morphological features
4) Perfusion technique
26. During respiration living organisms can convert pyruvate to Acetyl CoA via
1) oxidative decarboxylation
2) alcoholic fermentation
3) lactic acid fermentation
4) none of the above
27. Which of the following statements does not correctly describe the structure of glycogen?
1) It is a mixture of two branched chain homopolysaccharides.
2) Glucose molecules are the monomeric units of the polysaccharide.
3) The monomeric units of the polysaccharides are joined together by  1  4 and
 1 6 glycosidic bonds.
4) All are correct.
28. Which of the following statements is incorrect?
During TCA cycle
1)
2)
3)
4)
Oxygen molecules are used for the oxidation of acetyl CoA.
The product of oxidation is CO2 .
NADH + H+ and FADH2 are formed.
Oxaloacetate is regenerated.
29. Which of the following components of electron transfer chain in mitochondria are mobile
electron carriers?
1) complex 1and 2.
2) ubiquinone
3) cytochrome c
4) cytochrome a and a3.
30. Which of the following are regulatory enzyme(s) for glycolytic pathway?
a) hexokinase
b) pyruvate kinase
c) phosphogycerate kinase
d) all of the above.
Choose the correct answer from the key given below:
1)
2)
3)
4)
a and b
a and c
b and c
a, b and c.
8
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
2) 20
3) 21
4) 22
35. In prokaryotes the P-site and A-sites are located in ………………… subunit of the
ribosome.
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
centromere?
1) Prophase
2) Metaphase
3) Anaphase
4) Telophase
9
39. In which cell meiosis occurs?
1) Somatic cell
2) Nerve cell
3) Apical cell
4) Pollen cell
40. In which phase of meiosis chromatids of two homologous chromosomes exchange segments
during crossing over?
1) Pachytene
2) Diplotene
3) Diakinesis
4) Leptotene
41. Breakdown of mitotic spindle can occur by exposing the cell to
1) calcium
2) calmodulin
3) tubulin
4) colchicine
42. Duplication of DNA in the cell cycle occurs during
1) G1 phase
2) S phase
3) G2 phase
4) Interphase
43. Intracellular recognition and therefore aggregation of slime mold is brought about by
1) incubating the mold in sea water devoid of Ca2+ and Mg2+.
2) binding of specific factors to specific surface proteins with the help of Ca2+.
3) responding to cAMP synthesized and secreted by individual cells.
4) mixing of the individual cells in a pool of nutrients.
44. In response to the stimulus created by particles binding to the surface receptors the
phagocytes extend
1) lamellipodia
2) filopodia
3) pseudopods
4) cilia
45. Basal lamina is
1) carbohydrates
2) epithelial cell layer
3) extracellular matrix layer
4) glycosaminoglycans
46. Which neurons convey information from central nervous system to the effector organs such
as muscles, glands etc.?
1) Motor neurons
2) Sensory neurons
3) Neurosecretory neurons
4) Internuncial neurons
10
47. Hard bone without any space is called as
a) spongy bone
b) replacing bone
c) decimal bone
d) compact bone
48. White blood cells with pear shaped large nuclei are
1) lymphocytes
2) thrombocytes
3) basophiles
4) monocytes
49. Tracheids are
1) a column of thin-walled living elongated cells with perforated end walls through which
strands of cytoplasm pass to connect the neighbouring cells.
2) elongated cells with tapering ends and cross walls, connected to the neighbour cell by
pairs of pits.
3) cells arranged in tube-like form with no cross-walls for transport of water.
4) all are correct.
50. A tissue which consist of rounded cells enclosed in a small cell wall, containing air filled
intercellular spaces is:
1) parenchyma
2) sclerenchyma
3) collenchyma
4) aerenchyma.
11
INDIRA GANDHI NATIONAL OPEN UNIVERSITY
RESPONSE SHEET FOR COMPUTER MARKED ASSIGNMENT
Enrolment No.
Programme
: B.Sc.
Course Code
: LSE-01
Assignment Code: LSE-01/AST-2/CMA-1/2003
Name &
Address
(Block
Letters)
Pin Code
Signature _____________________
Date :
_____________________
Question No. 1
Answers
2
3
4
5
6
7
8
9
10
Question No. 11
Answers
12
13
14
15
16
17
18
19
20
Question No. 21
Answers
22
23
24
25
26
27
28
29
30
Question No. 31
Answers
32
33
34
35
36
37
38
39
40
Question No. 41
Answers
42
43
44
45
46
47
48
49
50
For Office Use Only
Entered by……………………
Total Questions Attempted: ………………………….
Verified by……………………
Wrong Answers
: …………………………………
Total Marks
: …………………………………
Grade Obtained
: ……………………………...
12