Dear Students,
Welcome to Molecular Biology MCQ-10 (Molecular Biology CSIR NET Questions) This MCQ set consists of Advanced (Post Graduate Level) Molecular Biology Multiple Choice Questions with Answer Key. All these questions were taken from the previous year question papers of CSIR JRF NET Life Sciences Examination. These questions can be used for the preparation of Competitive examinations in Biology / Life Sciences such as CSIR JRF NET, ICMR JRF, DBT BET JRF, GATE and other University Ph.D Entrance Examinations. After marking your answers, please click ‘SUBMIT‘ button to see your ‘SCORE‘ and ‘CORRECT ANSWERS‘.
You may also like: Molecular Biology Notes | Molecular Biology PPT
(1). The tetra-peptide KDEL is well known as retrieval signal for several newly synthesized proteins. This process is mediated through specific receptor – KDEL interaction. Any single amino acid change in this tetra-peptide is not allowed in terms of its binding with its receptors and its subsequent retention in specific organelle whereas; secretory proteins are devoid of such tetra-peptide. From this observation indicate the localization of the receptor of this tetra-peptide: (CSIR JRF NET_2015_I)
(a). Plasma membrane
(b). Golgi
(c). Endoplasmic reticulum
(d). Mitochondria
(2). The following statements are made on DNA replication:
(A). Replication form is a branched point in a replication ‘eye’ or ‘bubble’.
(B). A replication bubble contains two replication forks
(C). DNA replication is continuous according to the interpretation make by Okazaki
(D). Multiple priming events are required for both leading and lagging strands to initiate DNA synthesis.
Which one of the following is the correct combination? (CSIR JRF NET_2015_I)
(a). (A) and (B)
(b). (B) and (C)
(c). (C) and (D)
(d). (A) and (C)
(3). The following statements have been proposed for a cancer cell.
(A). Binding of p53 with MDM2, a ubiquitin E3 ligase, is a precondition for cancer progression
(B). Phosphorylation of a tyrosine residue in the C-terminus of human c-Src is essential for cell invasion and motility
(C). Loss of function of both alleles of a tumor suppressor gene prevents metastasis
(D). Dimerization of c-myc-Max leads to enhanced cell proliferation
Which of the combinations of the above statements is correct? (CSIR JRF NET_2015_I)
(a). (A) and (B)
(b). (C) and (D)
(c). (A) and (D)
(d). (B) and (C)
(4). In prokaryotes, the initiatior t-RNA is first charged with a methionine, followed by the addition of a formyl group to the methionine by the enzyme Met-tRNA transformylase. Given below are several statements in this context.
(A). All prokaryotic proteins have formyl methionine at their amino-terminal end.
(B). Deformylase removes the formyl group from the amino terminal methionine.
(C). All prokaryotic proteins have methionine at their amino terminal end.
(D). Aminopeptidases often remove the amino terminal methionine.
(E). Aminopeptidases remove amino terminal formyl methionine.
Which of the above statement(s) are most likely to be true? (CSIR_2015_II)
(a). A only
(b). B and C
(c). E only
(d). B and D
(5). Which one of the following statements about the nuclear receptor superfamily is NOT true? (CSIR_2015_II)
(a). The receptors are always cytosolic, where they remain associated with heat-shock proteins and has variable ligand binding domains in the N-terminal region.
(b). The receptors have characteristic repeat of the C4 zinc-finger motif
(c). The receptors are either homodimeric or heterodimeric, and in the absence of their hormone ligand, the heterodimeric receptors repress transcription, when bound to their response elements.
(d). The receptors have a unique N-terminal region of variable length and may contain a nuclear localization signal between the DNA- and ligand-binding domains.
(6). The genome of a bacterium is composed of a single DNA molecule which is 109 bp long. How many moles of genomic DNA is present in the bacterium? [Consider Avogadro No. 6 X 1023]. (CSIR_2015_II)
(a). 1/6 X 10-23
(b). 1/6 X 10-14
(c). 6 X 1014
(d). 6 X 1023
(7). Given below are events in the cell cycle. (CSIR_2015_II)
(a) Phosphorylation of lamin A, B, C
(b) Phosphorylation of Rb (Retinoblastoma protein)
(c) Polyubiquitination of securin
(d) Association of inner nuclear membrane proteins and nuclear pore complex proteins with chromosomes.
Which one of the following reflects the correct sequence of events in the mammalian cell cycle?
(a). a→b→c→d
(b). b→c→d→a
(c). c→a→b→d
(d). b→a→c→d
(8). Which one of the following chemicals is a DNA intercalator? (CSIR_2015_II)
(a). 5-Bromouracil
(b). Ethyl methane sulfonate
(c). Acridine orange
(d). UV
(9). α-Amanitin is a fungal toxin which inhibits eukaryotic RNA polymerases. The three eukaryotic RNA polymerases show differential sensitivity to this toxin. Which one of the following order (higher to lower) is correct in respect of sensitivity towards α-amanitin? (CSIR_2015_II)
(a). RNA POL III > RNA POL II > RNA POL I
(b). RNA POL II > RNA POL III > RNA POL I
(c). RNA POL I > RNA POL III > RNA POL II
(d). RNA POL II > RNA POL I > RNA POL III
(10). In eukaryotic replication, helicase loading occurs at all replicators during (CSIR_2015_II)
(a). G0 phase
(b). G1 phase
(c). S phase
(d). G2 phase
Answer Key
(1). Ans. (c). Endoplasmic Reticulum
(2). Ans. (a). (A) and (B)
(3). Ans. (c). (A) and (D)
(4). Ans. (d). (B) and (D)
(5). Ans. (a). The receptors are always cytosolic, where they remain associated with heat-shock proteins and has variable ligand binding domains in the N-terminal region.
(6). Ans. (a). 1/6 X 10-23
(7). Ans. (d). b→a→c→d
(8). Ans. (c). Acridine orange
(9). Ans. (b). RNA POL II > RNA POL III > RNA POL I
(10). Ans. (b). G1 phase
Cells and transport process