(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
(5). Most of the nutrients are absorbed from the intestine by co‐transport. Which of the following mineral plays important role in transport of amino acids across intestine epithelium?
a. K
b. Ca
c. Na
d. Na and Ca both
(6). E. coli cells were transformed with a plasmid carrying tetracycline resistance gene and later they plated on LB medium and various colonies were observed but same the number of colonies were observed for control non transformed E. coli cells. The probable reason is
a. No transformation has occurred
b. Bacteria are plated just after heat shock and incubation with plasmid
c. E. coli cells were already resistant to tetracycline
d. Wrong plasmid was used
(7). Vif gene is one of the important regulatory genes in the lifecycle of HIV virus. It was observed that HIV virus with mutated Vif gene fails to culture of normal T‐helper cells. The main reason is
a. Vif gene helps in reverse transcription process
b. Vif gene helps in transport of HIV genome to nucleus
c. Vif gene helps in the insertion of the viral genome into host genome
d. Vif product targets the enzyme responsible for hyper-mutation to ubiquitination and cellular degradation
(8). The major function of surfactant protein secreted by the lungs is:
a. Do not allow growth of bacteria
b. Stops entry of dust particles into lungs
c. Keeps alveoli inflated
d. Helps in absorption of oxygen
(9). In brain, meninges are absent at
a. Dura mater
b. Pia mater
c. Grey mater
d. Arachnoid mater
(10). Which plant has been used in phytoremediation for uptake of cadmium from the contaminated soil?
a. Helianthus annus
b. Brassica juncea
c. Silene vulgaris
d. Oscimum basalicum
(11). Action potential is fired after threshold stimulus but once the nerve impulse there is the interval during which a second action potential cannot be initiated, no matter how large a stimulus is applied. This gap is termed as
a. Absolute refractory period
b. Relative refractory period
c. Threshold period
d. Resting potential
(12). Nick translation means
a. Translation by cytosolic ribosome
b. Translation of protein from stalled sites
c. Replication by DNA polymerase I after removing RNA primers
d. Replication of DNA by DNA polymerase I from nicks produced by DNase treatment
(13). According to the Holiday model if markers are present outside of crossover point, then recombinant molecules would be generated when
a. There is no resolution
b. Always recombinant would be produced
c. Nick is on outer strand during resolution
d. Nick is on inner strand during resolution
(14). Which phylum is characterized by the absence of body symmetry, no tissue or organ and lack of nervous system?
a. Porifera
b. Cnidaria
c. Pteniphora
d. Rhyzopoda
(15). Secondary structure of RNA is stabilized by hydrogen bonding between
a. GC and AU
b. GC and AT
c. GC, AU and GU
d. GC only
(16). What is the basic assumption for using molecular clocks for estimation of molecular evolution?
a. The rate of neutral mutation is constant over time
b. The rate of evolution is constant over time
c. DNA does not show variations among organisms
d. Proteins are better marker for phylogeny as compared to DNA
(17). In an experiment bacterial cell was removed using enzymatic methods. It was observed that on culturing such bacteria, for many generations cell wall was not seen. It is proof to
a. Inheritance of acquired character
b. Recessive mutation
c. Reverse mutation
d. Adaptive mutation
(18). Among the following which DNA polymerase lacks proofreading activity?
a. DNA polymerase α
b. DNA polymerase δ
c. DNA polymerase ε
d. DNA polymerase α and ε
(19). Which statement is correct for archaebacteria?
a. Lacks histone protein
b. Have 9+2 arrangement in flagella
c. Lacks introns in genes
d. Cell wall is made up of peptidoglycan
(20). ABC transporters are NOT involved in
a. Transport of chloroplast content for degradation in vacuole
b. Accumulation of pigment in plant vacuole
c. Secretion of matting factor in yeast
d. Uptake of phosphate by bacteria
CSIR JRF NET Life Sciences December (II) 2017 Exam Model Questions
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Answer Key
1. Ans. (c). Low tryptophan
2. Ans. (d). Puromycin
3. Ans. (a). Change at first U
4. Ans. (b). Nitrite reductase
5. Ans. (c). Na
6. Ans. (c). E. coli cells were already resistant to tetracycline
7. Ans. (d). Vif product targets the enzyme responsible for hyper-mutation to ubiquitination and cellular degradation
8. Ans. (a). Do not allow growth of bacteria
9. Ans. (c). Grey mater
10. Ans. (b). Brassica juncea
11. Ans. (a). Absolute refractory period
12. Ans. (d). Replication of DNA by DNA polymerase I from nicks produced by DNAse treatment
13. Ans. (c). Nick is on outer strand during resolution
14. Ans. (d).Rhyzopoda
15. Ans. (c). GC, AU and GU
16. Ans. (a). Rate of neutral mutation is constant over time
17. Ans. (a). Inheritance of acquired characters
18. Ans. (d). DNA polymerase α and ε
19. Ans. (d). Lacks histone protein
20. Ans. (a). Transport of chloroplast content for degradation in vacuoles