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  #2  
30th October 2014, 11:48 AM
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Join Date: Apr 2013
Re: UGC Life Science Exam Papers

CSIR (Council of Scientific & Industrial Research) organize Joint CSIR UGC National Eligibility Test (NET) twice a year in month of June and December. Subjects of exams are following:

Chemical Sciences
Earth
Atmospheric
Ocean and Planetary Sciences
Life Sciences
Mathematical Sciences
Physical Sciences
Engineering Sciences

Now, here I am giving you Model question Papers for preparation of UGC Life Science Exam.





Attached Files
File Type: pdf UGC Life Science Exam Paper 1.pdf (1.32 MB, 74 views)
File Type: pdf UGC Life Science Exam Paper 2.pdf (4.23 MB, 67 views)
  #3  
21st May 2015, 02:00 PM
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Re: UGC Life Science Exam Papers

I am applying for UGC NET Exam in Life Science. So I am looking for some Question Papers of UGC Net Life Science Exam. So can you give me some UGC Net Life Science Exam Papers?
  #4  
21st May 2015, 02:02 PM
Super Moderator
 
Join Date: Apr 2013
Re: UGC Life Science Exam Papers

Here you are searching for UGC Life Science Exam Papers, so here you will get Exam papers of UGC Net Life Science Exam.

UGC NET Life Science Model Exam Paper
21. Which of the following bonds will be most difficult to break?
1. C–O
2. C–C
3. C–N
4. C–S
22. A solution of 1% (w/v) starch at pH 6.7 is digested by 15 µg of -amylase (mol wt
152,000). The rate of maltose (mol wt = 342) had a maximal initial velocity of 8.5 mg
formed per min. The turnover number is
1. 0.25  105 min–1.
2. 25  105 min–1.
3. 2.5  105 min–1.
4. 2.5  104 min–1.
23. The conformation of a nucleotide in DNA is affected by rotation about how many bonds?
1. 4
2. 6
3. 7
4. 3
24. Which of the following proteins acts as an energy transducer?
1. G-protein.
2. Bacteriorhodopsin.
3. Hemoglobin.
4. Heat shock protein.
25. Which of the following predicted property of lipid bilayers would result if the
phospholipids had only one hydrocarbon chain instead of two?
1. The bilayers formed would be much less fluid.
2. The diameter of the head group would be much larger than the acyl chain and would
tend to form micelles rather than bilayers.
3. the bilayers formed would be much more fluid.
4. the bilayers would be more permeable to small water-soluble molecules.
26. Which pump is responsible for initiating muscle contraction through depolarization of
muscle cell membrane?
1. Na+ pump.
2. K+ pump.
3. Ca2+ pump.
4. Mg2+ pump.
27. Which of the following statements is not true for transposable element system?
1. It consists of both autonomous and non-autonomous elements.
2. Dissociation elements are autonomous in nature.
3. Transposase is transcribed by the central region of autonomous elements.
4. Certain repeats in the genome remain fixed even after the element transposes out.
28. A set of virulence genes (vir genes), located in the Agrobacterium Ti-plasmid, is activated
by
1. octopine.
2. nopaline.
3. acetosyringone.
4. auxin.
29. When two mutants having the same phenotype were crossed, the progeny obtained showed
a wild-type phenotype. Thus the mutations are
1. non-allelic.
2. allelic.
3. segregating from each other.
4. independently assorting.
30. A conjugation experiment is carried out between F+ his+ leu+ thr+ pro+ bacteria and F– his–
leu– thr- pro- bacteria for a period of 25 minutes. At this time the mating is stopped, and the
genotypes of the recipient F– bacteria are determined. The results are shown below:
Genotype Number of colonies
his+ 0
leu+ 13
thr+ 26
pro+ 6
What is the probable order of these genes on the bacterial chromosome?
1. thr, leu, pro, his
2. pro,leu, thr and the position of his cannot be determined.
3. thr, leu, pro, and the position of his cannot be determined.
4. his, pro, leu, thr
31. Two varieties of maize averaging 48 and 72 inches in height, respectively, are crossed.
The F1 progeny is quite uniform averaging 60 inches in height. Of the 500 F2 plants, the
shortest 2 are 48 inches and the tallest 2 are 72 inches. What is the probable number of
polygenes involved in this trait?
1. Four.
2. Eight.
3. Sixteen.
4. Thirty two.
32. Repair of double strand breaks made during meiosis in the yeast Saccharomyces cerevisiae
1. occurs mostly by non-homologous end joining.
2. occurs mostly using the sister chromatid as a template.
3. occurs mostly using the homologous chromosome as a template.
4. is associated with a high frequency of mutations.
33. Which of the following signaling molecules enters the cell to initiate its action?
1. Transferrin
2. Insulin
3. Glucagon
4. Thyroxine
34. The mode of action of the anticancer drug methotrexate is through its strong competitive
inhibition on
1. dihydrofolate reductase.
2. thymidine synthase.
3. thymidine kinase.
4. adenylate cyclase.
35. Which class of immunoglobulins will increase in case of a chronic infection?
1. IgA
2. IgG
3. IgM
4. IgE
36. When prospective neuroectoderm from an early amphibian gastrula is transplanted in the
prospective epidermal region of a recipient (early gastrula) embryo, the donor tissue will
give rise to
1. neural tube.
2. epidermis.
3. neural tube and notochord.
4. neural tube and epidermis.
37. Amphibian oocytes remain for years in the diplotene stage of meiotic prophase.
Resumption of meiosis is initiated by
1. gonodatropic hormone.
2. growth hormone.
3. oestrogen.
4. progesterone.
38. A group of six cells called 'equivalence group cells' divide to form the vulval structure in
Caenorhabditis elegans. They are called so because
1. they have similar fates during development of vulva.
2. all the six cells are competent to form vulva and can replace each other under various
experimental conditions.
3. they are all under the influence of the anchor cell, signals from which initiate
vulval development.
4. they interact with each other to form the vulval structure.
39. Due to the presence of cellulose in the cell wall of plants, leaf shape is determined in the
leaf primorida by
1. rates of cell division.
2. planes of cell division.
3. cell migration.
4. cell-cell interactions.
40. DCMU inhibits electron transport in chloroplast by preventing the reduction of
1. P 680.
2. QA.
3. PQ.
4. QB.
41. In higher plant leaves, the reduction of nitrate to ammonium takes place by the combined
action of nitrate reductase localized in cytosol and nitrite reductase localized in
1. peroxisomes.
2. mitochondria.
3. chloroplasts.
4. cytosol.
42. In higher plants, the red/far-red sensory photoreceptor, phytochrome, is a light-regulated
kinase. Which of the following classes of kinases does it represent?
1. Two-component sensor regulator (histidine kinase).
2. Two-component sensor regulator (serine/threonine kinase).
3. Leucine rich repeat (LRR) receptor kinase.
4. Calcium-dependent protein kinase.
43. Vesicular-arbuscular mycorrhiza (VAM) represents a beneficial association between plant
roots and fungus, where fungus assists plants in obtaining from the soil
1. iron.
2. zinc.
3. sulphate.
4. phosphate.
44. Unidirectional propagation of electrical signal in nervous system is
1. proportional to the length of axon.
2. due to chemical synapse.
3. due to electrical synapse.
4. proportional to myelination.
45. A myasthenia gravis patient develops muscle paralysis because
1. the nerve terminal at the neuromuscular junction fails to release acetylcholine.
2. although enough acetylcholine is released at the neuromuscular junction, it is
destroyed by acetylcholinesterase.
3. the patient develops immunity against his own acetylcholine receptor.
4. the patient develops antibody against his own acetylcholine.
46. Inhibin from sertoli cells of testes selectively inhibits
1. luteinizing hormone.
2. follicle stimulating hormone.
3. thyroid stimulating hormone.
4. growth hormone.
47. Hawk's retina possesses a large number of
1. rods.
2. melanocytes.
3. cones.
4. kuffer cells.
48. E. coli cells were grown in N15 medium for several generations and then shifted to normal
medium for one generation. If the DNA isolated from the culture would be centrifuged on
a CsCl equilibrium density gradient, the result will be
1. a single band of double helix DNA consisting of one strand with N14 and another
with N15 label.
2. single band of double helix DNA consisting of N14 and N15 in both the
strands.
3. two bands containing double helix DNA each containing both N14 and N15 label.
4. two bands containing single stranded DNA one with N14 and other with N15
label.
49. Which of the following processes does not take place in the 5′→3′ direction?
1. DNA replication
2. Transcription
3. Nick translation
4. RNA editing
50. A deletion of three consecutive bases in the coding region of a gene cannot result in
1. deletion of a single amino acid without any other change in the protein.
2. replacement of two adjacent amino acids by a single amino acid.
3. replacement of a single amino acid by another without any other change in
sequence of the protein.
4. production of a truncated protein.
51. Deletion of the leader sequence of trp operon of E. coli would result in
1. decreased transcription of trp operon.
2. increased transcription of trp operon.
3. no effect on transcription.
4. decreased transcription of trp operon in the presence of tryptophan.
52. In the endodermis of higher plants, the role of Casperian strip is to control the water
movement so that it flows
1. between the cells.
2. through the plasma membrane.
3. through the cell wall.
4. through the transfusion tissue.
53. The reptilian order Squamata includes
1. crocodiles and alligators.
2. the living fossil 'tuatara'.
3. turtles and tortoises.
4. snakes and lizards.
54. Cultivated bananas are sterile because
1. male flower-bearing plants are very rare.
2. they lack natural pollinators in the crop plants.
3. they are triploid and therefore seeds are not set.
4. they are a cross of two unrelated species.
55. One life history trait that is not characteristic of very small sized organisms is
1. delayed age at first reproduction.
2. earlier age at first reproduction.
3. high population growth rate.
4. short lifespan.
56. Which of the following statements is the most appropriate example of character
displacement?
1. Two related species depending on the same prey species avoid competition by
feeding at different times of the day.
2. The body sizes of two related species are very similar when they are allopatric,
but in geographical areas of sympatry, one species is significantly smaller than
the other.
3. The food niche of a species is generally wider in the absence of competing species
than in their presence.
4. Closely related species can coexist if their densities are regulated by a predator.
57. In a population growing logistically and approaching Carrying Capacity (K), the
change in density (N) per unit time (dN/dt) is maximum when N equals to
1. K2
2. K/2.
3. K.
4. K.
58. The losses of ozone over Arctic are significantly lower than that over Antarctica
because
1. polar vortex over Arctic is not as tight as over Antarctic.
2. Arctic stratosphere warms slower in the spring.
3. concentration of chlorine in the atmosphere over Arctic is less than over
Antarctic.
4. freezing of NO2 and CH4 are slower over Arctic than over Antarctic.
59. Which of the following species replacement sequence depicts tolerance model of
community succession?
A B
C D
A B
C D
D
CD
A B
C D
A B
1
2
3
4
BCD
1 2 3 4 5 6 7 8 9 10
Trait value Trait value
1 2 3 4 5 6 7 8 9 10
60. Evolutionarily, with which of the following could parental care in animals be
associated?
1. Smaller clutch size.
2. Polygamy.
3. Greater longevity.
4. Semelparity.
61.
The change in a trait with time as a result of natural selection is shown above. This
type of natural selection is
1. directional.
2. disruptive.
3. stabilizing.
4. random.
62. During which geological period did the greatest diversification of life on earth occur?
1. Permian
2. Jurassic
3. Cambrian
4. Ordovician
63. Which of the following plant groups evolved during the Silurian period?
1. Bryophyta
2. Psilophyta
3. Lycophyta
4. Spherrophyta
64. Which of the following GM crops is the most widely cultivated globally?
1. Herbicide resistant soybean.
2. Insect resistant cotton.
3. Insect resistant brinjal.
4. delayed ripening tomato.
65. PCR based DNA amplification is an essential feature of which of the following
combination of molecular markers?
1. RFLP, AFLP and SSR.
2. AFLP, SSR and RAPD.
3. RFLP, RAPD and SSR.
4. RAPD, RFLP and SSR.
66. The genes whose promoters are extensively used for production of pharmaceutical
proteins in transgenic dairy cattles are
1. lactalbumin and ovalbumin.
2. lactoglobulin and casein.
3. lactoferrin and transferrin.
4. casein and ovalbumin.
67. A biochemist purifies a new enzyme, generating the following purification table.
S. No. Procedure Total protein
(mg)
Activity
(units)
i. Crude Extract 20,000 4,000,000
ii. Salt precipitation 5,000 3,000,000
iii. Ion-exchange
chromatography
200 800,000
iv. Affinity chromatography 50 750,000
v. Size-exclusion
chromatography
45 675,000
The most effective purification step is
1. iv.
2. iii.
3. v.
4. ii.
68. Similarities in sequence and function of two proteins indicate that they are members
of a family that share a common ancestor. If they are from different species, they are
called
1. homologs.
2. orthologs.
3. paralogs.
4. proteologs.
69. The conformation of a 30-residue peptide is studied by NMR spectroscopy. The JNH
for most of the amide protons is 4Hz. The 2D NOESY spectrum shows prominent
Ni-Ni+1 connectivities. The conformation of the peptide is
1. anti-parallel  sheet.
2. parallel  sheet.
3. helix-like.
4. unordered.
70. A sample of 32P disintegrates at a rate of 30,120 dpm. The radioactivity in
microcuries (1 curie=3.7x1010dps) is
1. 15,060.
2. 1.36x10-2.
3. 81.6 x10-2.
4. 1.36 x10-8.
PART C
71. A protein polypeptide chain exists in -helical conformation in a solvent and it has a
value of -30,000 deg cm2 dmol-1 for the mean residue ellipiticity at 222 nm ([ ]222) in the
temperature range 20-50C. On raising the temperature above 50C,[ ]222 increases and
reaches a value of -2,000 deg cm2 dmol-1 at 70C and the value of [ ]222 remains
unchanged above 70C. The observed value of [ ]222 is -14,000 deg cm2 dmol-1 at 60C.
If one assumes that the heat-induced denaturation is a two-state process, the fraction of -
helix at 60C is
1. 0.40
2. 0.43
3. 0.50
4. 0.57
72. 100 ml of 0.02 M acetic acid (pKa= 4.76) is titrated with 0.02 N KOH. After adding
some base to the acid solution, the observed pH is 2.76. At this pH degree of protonation
is
1. 0%.
2. 10%.
3. 90%.
4. 99%.
73. There are hydrogen bond donors (D), and acceptors (A). When the mixture (A+D) is
transferred from water, designated as (w) to a nonpolar solvent (np), the free energy
change (G) of transfer is 6.12 kcal mol-1 for the (A+D) mixture. A and D form a
hydrogen bond in this nonpolar solvent and G for this process is – 2.4 kcal mol-1. When
the hydrogen bonded molecule A-D is transferred from water to the nonpolar solvent G
for this process is 0.62 kcal mol-1. The value of G for the formation of hydrogen bond
(A+B  A-B) in water is
1. -0.1 kcal mol-1.
2. +3.1 kcal mol-1.
3. -3.1 kcal mol-1.
4. -1.78 kcal mol-1.
74. In a human cell, the concentration of ATP, ADP and Pi are 2.25, 0.50 and 0.825mM
respectively. The free energy of hydrolysis of ATP at pH 7.0 and 25°C is
1. –30.5kJ/mol.
2. –61kJ/mol.
3. –15.25 kJ/mol.
4. –52 kJ/mol.
75. Which one of the following enzyme reaction represents noncompetitive initiation?
1. E+S      ES + E + P
ES + I I K       EI
2. E+S      E+S  E + P
ES + I
1 K
      ESI
3. E+S1      ES1      EʹP1 1 P        Eʹ 2 S          EʹS2 E+P2
4. E+S      ESE+P
E+S+I I K       EI + S
ES + I
I K
  ESI
EI + S       ESI
76. The sequence of monosaccharides including position and configuration of glycosidic
bonds in a glycoprotein is to be determined. Which one of the following methods can be
employed?
1. Glycoprotein removal of oligosaccharides by alkaline
hydrolysis nuclear magnetic resonance analysis of cleaved mixture
of oligosaccharides
2. Two dimensional nuclear magnetic resonance spectroscopic analysis of
the glycoprotein
3. Glycoprotein release of oligosaccharides with endoglycosidases
followed by purification to separate oligosaccharides enzymatic
hydrolysis of purified oligosaccharides with specific
glycosidases mass spectroscopic analysis of smaller
oligosaccharides
4. Glycoprotein  treat with trypsin followed by MALDI analyses of
tryptic peptides
77. A bacterial culture undergoing balanced growth requires a first-order reaction. In other
words, the rate of increase in bacteria at any particular time is proportional to the number
or mass of bacteria present at that time. If „N‟ is the number of cells at any given time „t‟
and „ ‟ is „growth rate constant‟ this process can be expressed mathematically as
1. N
dt
dN
  .
2. N
dN
dt
  .
3. N
dt
d


.
4.   N
dt
dN
.
78. A typical animal cell (nucleated) membrane contains glycolipids and glycoproteins in the
plasma membrane. To determine its topological distribution, „lectin‟ is used as a probe.
The following interactions may be the basis of the probing method:
(A) Protein-protein interaction
(B) Protein-sugar interaction
(C) Protein-lipid interaction
(D) Protein-sterol interaction.
The appropriate answer is
1. Only (A).
2. Only (B).
3. All of (A), (B) and (C).
4. Only (D).
79. Upon studying a considerable number of different crosses in Drosophila, Morgan reached
the conclusion that all genes of this fly were clustered into four linked groups
corresponding to the four pairs of chromosomes. Further studies revealed that linkage is
not absolute and it is broken frequently. It is broken in prophase by a process called
1. Recombination.
2. Jumping of genes.
3. Integration.
4. Mutation.
80. A population of proliferating cells is stained with a DNA binding fluorescence dye so that
the amount of fluorescence is directly proportional to the quantity of DNA. Amount of
DNA in each cell is measured by flow cytometry. The number of cells with a given DNA
content is plotted and following statements were made:
(1) Peak A contains the cells of G1 phase
(2) Peak B contains the cells of G2 phase
(3) Peak A contains the cells of G2 phase
(4) Peak B contains the cells of G1 phase
Which of the above mentioned statement is correct?
1. (1) and (2).
2. (3) and (4).
3. (2) and (4).
4. (1 ) and (3)
81. During many important cell processes, many proteins need to undergo degradation to
culminate a part of the process. For example, during cell cycle, cycling proteins need to
be degraded to allow the cells to exit mitosis. This is achieved by selective ubiquitination
of cyclin followed by its degradation by proteasomes. The specific protein factor that is
involved in this process is called Anaphase Promoting Complex (APC). APC is possibly
a protein which is known as
1. E1 enzyme.
2. E2 enzyme.
3. E3 enzyme.
4. Protease.
82. During mitogenic stimulation, cells proliferate at a higher rate and it is primarily
determined by an enhanced rate of protein synthesis. Among other mechanisms, MAP
kinase pathway of signal transduction is involved in this. Global protein synthesis may be
regulated by many mechanisms involving various steps of protein synthesis, namely,
initiation, elongation and termination. Thus, many protein factors may be involved in the
same. In the above process (mitogenic stimulation) the following factors are the portable
targets.
A. elF -2
B. eEF-1
C. S6 kinase
D. elF-4E BP
The correct answer is
1. A+B
2. C+D
3. D+A
4. B+D
83. DNA repair, synthesis and recombination are intimately connected and inter dependent.
An apparent commonality between processes of DNA replication and repair in the
enzymatically catalyzed synthesis of DNA polynucleotide segments, which can be
assembled with preexisting polynucleotides, leading to repair or replication. Synthesis of
these polynucleotide segments is catalyzed by a group of enzymes DNA-dependant DNA
polymerases. In the case of E.coli, DNA polymerase has been isolated in three distinct
forms whereas five main types of polymerase have been isolated from mammalian cells.
All the polymerases synthesize polynucleotides only in the 5' 3' direction. If
polynucleotide chains could be elongated in 3' 5' direction, the hypothetical growing 5'
terminus, rather than the incoming nucleotide, would carry a triposphate that is unsuitable
for further elongation. The 3' 5ʹ exonuclease activity is not associated with all the
polymerases and only present in
(A) All E. coli DNA polymerases but not all mammalian polymerases.
(B) Pol I, Pol II, Pol III, Pol , Pol .
(C) Pol I, Pol II, Pol , Pol, Pol 
(D) Pol I, Pol II, Pol, Pol .
The correct statements are
1. (A) and (B).
2. (A), (B) and (C).
3. (A) and (C).
4. (A), (C) and (D).
84. Bacteriophage  genetic circuit may be represented as follows:
The control of gene expression occurred during the phage infection may be described as
follows:
(A) N and Q protein act as antiterminator
(B) CI acts only as repressor
(C) CII act as a retroregulator
(D) CI and CII both act as positive and negative regulator
Which one of the statements are correct?
1. (A), (B) and (C).
2. (B), (C) and (D).
3. (A) and (D) only.
4. (A), (C) and (D).
85. Rho factor is involved in termination of transcription in prokaryotes. Genetic
manipulations indicate that Rho-dependent termination requires the presence of a specific
recognition sequence on the newly synthesized RNA upstream of the termination site.
The recognition sequence must be on the nascent RNA rather than the DNA, as
demonstrated by Rho‟s inability to terminate transcription in the presence of pancreatic
RNAse. The essential features of this termination site have not been fully elucidated.
Construction of synthetic termination sites indicates that it consists of 80 to 100 nts that
lack a stable secondary structure and contain multiple regions that are rich in C and poor
in G.
Which of the following is/ are suggested by the above observation?
1. Rho factor attaches to nascent RNA at its recognition sequence and then
migrates along the RNA in the 5131 direction until it encounters an RNAP
paused at the termination site.
2. Rho unwinds the RNA-DNA duplex forming the transcription bubble, thereby
releasing the RNA transcript.
3. Rho factor attaches to the RNA at its recognition sequence while RNA is in the
RNA-DNA hybrid condition.
4. There may be other factors and hence Rho factor does not need to unwind the
RNA-DNA hybrid to release the transcript.
more paper detail to attached in a pdf file;
Attached Files
File Type: pdf UGC NET Life Science Model Exam Paper .pdf (365.7 KB, 240 views)


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