Life Science JRF NET Exam December 2017 Model Question Paper Set- 4


Life Science JRF Model Question

CSIR JRF/NET Life Science Exam December 2017 (II)
Model Question Paper 4/5

(CSIR MCQ015: Practice Questions with Answer Key)

(1). In an experimental approach, the trp operon and lac operon were fused. Under what condition there would be the expression of β‐galactosidase occurs.

a.       Low lactose and glucose
b.      High lactose and glucose
c.       Low tryptophan
d.      High tryptophan

(2). Which antibiotic is responsible for premature termination of translation in bacteria?

a.       Tetracycline
b.      Chloramphenicol
c.       Penicillin
d.      Puromycin

(3). In an m‐RNA, immature termination occurs from the codon UAA. Which of the following transition mutation will lead to its reversal

a.       Change at first U
b.      Change at first A
c.       Change at second A
d.      All of the above

(4). Which of the following enzyme of nitrogen metabolism is located in plastid?

a.       Nitrate reductase
b.      Nitrite reductase
c.       Aspartate synthetase
d.      Nitrogenase

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NET Life Sciences Model Question Paper June 2017 Set- 3


Life Science JRF Model Questions

CSIR JRF/NET Life Science Exam December 2017 (II)
Model Question Paper 3/5

(CSIR MCQ014: Practice Questions with Answer Key)

(1). A flow cytometer is used to measure the number of

a.       Cells
b.      DNA
c.       RNA
d.      Proteins

(2). How many H atoms would be replaced CCl4 in presence of ethanol during NMR spectrum?

a.       1
b.      2
c.       3
d.      4

(3). During the regulation of trp operon by the attenuation process, there is

a.       Immature termination of translation
b.      Immature termination of transcription
c.       Termination of replication
d.      Ribosome fails to read transcript

(4). An embryo lacking the bicoid is injected with bicoid m‐RNA at the middle portion. It will result in the formation of _______.

a.       Two heads and no tarsons
b.      Head in the middle and tarsons at both the ends
c.       No head and tarson at both ends
d.      Normal phenotype

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JRF NET Life Sciences June 2017 Free Model Question Papers Set- 2


NET Life Sciences Practice Questions

CSIR JRF/NET Life Science Exam December 2017 (II)
Model Question Paper 2/5

(CSIR MCQ013: Practice Questions with Answer Key)

You might like: NET Life Sciences Previous Year Papers (Download PDF)

(1). Most of the DNA binding protein binds to DNA by particular motif to modulate gene expression. Genes which are under the regulation of gibberllic acid have GRE where, GREB binds. The motif in GREB is ______

a.       Leucine Zipper
b.      bZIP
c.       Zinc finger
d.      Homoedomain

(2). Which of the following DONOT occur during seed development?

a.       Accumulation of storage proteins
b.      Synthesis of LEA proteins
c.       Desiccation
d.      Synthesis of Gibberellic acid

(3). The chemical salicyl hydroxamic acid inhibits

a.       Cytochrome oxidase
b.      Alternative oxidase
c.       ATP synthase
d.      NADH‐dehydrogenase

(4). Hardy‐Weinberg law will NOT operate under conditions¸ when

a.       3 alleles are involved
b.      Weak selection of one of the allele
c.       Skewed sex ratio
d.      Mutated allele is not involved in sexual selection

Learn more: Hardy Weinberg Equilibrium (easy explanation)

(5). Chromatids appear in the form of dyads during:

a.       Metaphase of mitosis
b.      Metaphase of meiosis
c.       Prophase of mitosis
d.      Anaphase of mitosis

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CSIR JRF NET Life Sciences December 2017 Model Question Paper Set- 1


NET 2017 Model Paper Life Sciences

CSIR JRF/NET Life Science Exam: Dec 2017
Model Question Paper 1/5

(CSIR MCQ012: Practice Questions with Answer Key)

(1).  The characteristics of organisms the reaches first to barren Island during the ecological succession:

a.       Slow growth and small generation time
b.      Slow growth and large generation time
c.       Fast growth and small generation time
d.      Fast growth and large generation time

Learn more: Process of Ecological Succession

(2). A myopic person is also suffering from astigmatism, to correct his vision which lens must be used:

a.       Plano-concave lens
b.      Plano-convex lens
c.       Combination of concave and cylindrical lens
d.      Combination of convex and cylindrical lens

(3). Fossil gives a better idea regarding the age of rocks because:

a.       Organic evolution is irreversible
b.      Rocks are formed after fossil deposition
c.       Rocks with fossils are stable
d.      Fossils do not allow weathering of rocks

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CSRI JRF NET Life Sciences June 2017 Model Question Paper Set- 4


biological significance of hydrogen bonds in water

CSIR JRF/NET Life Science Exam June 2017 (I)
Model Question Paper 4/4
(CSIR MCQ011: Practice Questions with Answer Key)

1.  Penicillin-resistant bacteria produce β-lactamase which inactivates penicillin by:

a.       Esterifying the carboxyl group
b.      Oxidizing S atom
c.       Hydrolyzing the side chain
d.      Hydrolyzing the C-N bond

Ans. (d)

β-lactamases or penicillinase are a class of enzymes produced by some bacteria which degrade penicillin antibiotic and thereby impart resistance against penicillin. All penicillin antibiotics contain a β-lactum ring structure which is essential for the antibiotic activity. The β-lactamase enzyme will degrade the β-lactum ring and thus inhibit the antibiotic properties.

2. Pseudo-murein is present in cell wall of:

a.       Streptococci
b.      Staphylococci
c.       Methanococci
d.      Micrococci

Ans. (c). Methanococci

Methanococci is an Archaebacteria.

Pseudo-murein or pseudo-peptidoglycan is a major cell wall component of some Archaebacteria. It is structurally different from the peptidoglycan of the true bacteria. However, it is functionally similar to the peptidoglycan wall of bacteria. Pseudo-murein is a hetero-polysaccharide of N-acetylglucosamine and N-acetyltalosaminuronic acid connected by β-1,3-glycosidic bonds. Lysozyme enzyme is unable to degrade the pseudo-murein cell wall.

Learn more: Difference between Murein and Pseudo-murein

Learn more: Comparison table of Bacteria, Archaea and Eukarya

3. Bacteria that can penetrate intact corneal epithelium is:

a.      Pseudomonas aeruginosa
b.      Staphylococus aureus
c.       Listeria monocytogenes
d.      Yersinia pestis

Ans. (b). Staphylococus aureus

4. Which of the following bacterial toxins does not have ADP-ribosyl transferase activity:

a.       Cholera toxin
b.      Diphtheria toxin
c.       Exotoxin A
d.      S aureus α toxin

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