CSIR JRF NET Life Sciences June 2014 Part B (Question 21 – 45)

CSIR/JRF/NET: Life Sciences, June 2014 (I)
(Original Question Paper)
PART: B (Questions 21 – 45)


21. Which one of the following is unfavorable for protein folding?

a. Hydrophobic interaction
b. Conformational entropy
c. van der Waals interaction
d. Hydrogen bonding

22. The maximum number of hydrogen bonds that can form between H2N – NH2 (hydrazine) and water is

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

23. The peptide unit (Cα – C’O – NH – Cα) is planar due to

a. Restriction around N – Cα bond
b. Restriction around Cα – C’ bond
c. Restriction around C’ – N bond
d. Hydrogen bonding between carbonyl oxygen and amino hydrogen of the peptide backbone

24. Which one the following is the most appropriate statement regarding folded proteins?

a. Charged amino acid side chains are always buried.
b. Tyrosine residues are always buried.
c. Charged amino acid side chains are seldom buried.
d. Non-polar amino acid side chains are seldom buried.

25. Molecules primarily responsible for the formation of lipid raft are

a. Phosphatidyl serine and phosphatidyl choline.
b. Glycosylphosphatidyl inositol and cholesterol
c. Phosphatidyl inositol and cholesterol
d. Sphingolipids and cholesterol

26. Membrane-bound and free ribosomes, are structurally identical, but differ only at a given time in terms of association with

a. Phospholipids
b. Acetylated proteins
c. Glycosylated proteins
d. Nascent proteins

27. Histone acetylase and chromatin remodeling complexes are required to specific regions of chromatin by

a. Gene activator proteins
b. Specific promoter sequence
c. Phosphorylation of histone acetylase
d. Dephosphorylation of chromatin remodeling complexes

28. The dye used in gram staining is

a. Methylene blue
b. Giemsa
c. Rhodamine
d. Crystal violet

29. Each origin of replication is activated only once. This is achieved because

a. Replication can only be initiated when pre-replication complex is intact.
b. Pre-replicative complex can only form in G1 and replication can only be initiated when pre-replication complex is disassembled at the beginning of S-phase.
c. Replication can only be initiated when unphosphorylated Rb is present.
d. Pre-replicative complex can only form in S-phase

30. The homologous genetic recombination is a DNA repair process referred to as recombination repair. Which one of the following statement is INCORRECT for recombination repair?

a. DNA polymerase III leaves a gap in the daughter strand
b. DNA polymerase III stalls at the site of the damage
c. The gap is filled by recombination between complementary parent strand and the gapped daughter strand
d. Homologous recombination process is catalyzed by topoisomerase II

31. During protein synthesis in prokaryotes, the peptidyl transferase activity required for peptide bond formation is due to:

a. Ribosomal protein L26
b. 23S ribosomal RNA
c. 16S ribosomal RNA
d. Amino acyl tRNA

32. After activation of promoter by the DNA binding activity of a transcription factor, a co-activator is recruited at the region targeted for transcription which in turn creates a binding site for a chromatin remodeling complex. Which one of the following activities of the co-activator is responsible for the recruitment of chromatin remodeling complex?

a. Histone methyl transferase activity
b. Histone acetyl transferase activity.
c. Histone deacetylase activity.
d. DNA methyl transferase activity.

33. Prior to transcription, chromatin changes from an inactive state to an active state by various factors in a step-wise manner. Which one of the following is involved in the initial step during activation of a chromatin loop?

a. HMG 14
b. Single stranded DNA binding protein.
c. DNA polymerase III
d. Topoisomerase I

34. A pathogen like Mycobacterium, which colonizes inside the cells of the host, is likely to be least affected by which one of the following host immune defense mechanism?

a. Humoral immune response
b. Cell-mediated immune response
c. CD4 T lymphocytes
d. Cytokines

35. Ethylene signaling pathway is important for fruit ripening. Which one of the following responses is routinely used to identify ethylene signaling pathway components?

a. Triple response
b. Cotyledon expansion response
c. Lateral root formation response
d. Flowering time response

36. Which one of the following is a type of intercellular junction in animal cells?

a. Glycocalyx
b. Middle lamella
c. Plasmodesmata
d. Desmosomes

37. Which one of the following is NOT related to immediate hypersensitivity reactions?

a. Mast cell degranulation results in histamine-mediated allergic reactions.
b. Granulomatous reactions is key to contain infection.
c. Reaginic antibodies trigger allergic reactions.
d. Anaphylactic reaction is triggered primarily by IgE

38. Which one of the following developmental process in animal is more dependent on cellular movements?

a. Morphogenesis
b. Pattern formation
c. Cell differentiation
d. Growth

39. Engrailed expression in Drosophila melanogaster defines:

a. Posterior margin of each para-segment.
b. Anterior margin of the segment.
c. Anterior compartment of each segment.
d. Posterior compartment of each segment

40. During which one of the following stages of Arabidopsis embryogenesis, cell elongation throughout the embryonic axis and further development of the cotyledons occur?

a. Torpedo stage
b. Heart stage
c. Globular stage
d. Mature stage

41. Which one of the following graphs represents the relative expression of proteins of Wnt-activated signaling cascades involved during development of an embryo?

net life sciences june 2014

NET Life Sciences June 2014 Original question paper

42. Virus induced gene silencing (VIGS) is a process that takes advantage of the RNAi-mediated antiviral defense mechanism. Which one of the following ultimately guides siRNA to degrade the target transcript (mRNA)?

a. ssRNA
b. dsRNA
c. RNA Induced Silencing (RIS) Complex
d. dsRNA binding protein

43. During the operation of C2 oxidative photosynthetic cycle, which of the following metabolites is transported from chloroplast to peroxisome?

a. Glycerate
b. Glycine
c. Serine
d. Glycolate

44. Arabidopsis thaliana seeds were planted on Murashige Skoog (MS) plates with or without a hormone added to the medium. Seeds were found to germinate late in the hormone containing MS plates as compared to MS plates without hormone. Identify the hormone.

a. Cytokinin
b. Jasmonic acid
c. Auxin
d. Abscisic acid

45. Which one of the following molecular marker types uses combination of both restriction enzyme and PCR techniques?

c. SSR
d. SNP
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