The first level of regulation of gene expression in eukaryotes is
A. Transcription
B. DNA methylation and chromatin structure
C. RNA processing
D. Post transcriptional modification
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Enzyme which digest nucleic acid by hydrolyzing phosphodiester bonds are called as
A. Nucleases
B. Deoxyribonucleases (if substrate is DNA)
C. Ribonucleases (if substrate is RNA)
D. All of the above
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The size of the maximum DNA insert that can be cloned in a YAC
A. < 300 kb
B. 100 - 300 kb
C. 70 - 100 kb
D. 200 - 2000 kb
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In a double stranded molecule of DNA, the ratio of purines : pyrimidines is
A. Variable
B. Determined by the base sequence in RNA
C. Genetically determined
D. Always 1 : 1
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The smallest plant genome identified
A. Chlorella
B. Oryza sativa
C. Arabidopsis
D. Ground nut
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Which one of the following amino acid has crucial role in the variability of protein structure?
A. Glycine
B. Cysteine
C. Aspartic acid
D. Glutamic acid
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Transcription is the process of
A. Synthesizing a DNA molecule from RNA template
B. Using DNA strand as a template to synthesize a complementary RNA molecule
C. Using DNA strand as template to synthesize identical RNA molecule
D. Synthesizing a protein using information carried in the nucleotide sequence of a messenger RNA
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The ability of proteins to absorb ultraviolet light is predominantly due to the presence of
A. Disulphide bond
B. Hydrophobic amino acids
C. Tryptophan
D. Hydrophilic amino acids
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Which of the following statement about the ribosome complex is correct?
A. Small subunit binds an mRNA and large subunit joint with the mRNA/small subunit complex to form a complete ribosome
B. The large ribosomal subunit has a P site (peptidyl site) that holds the growing polypeptide chain and an A site (aminoacyl site) that binds the next amino acid to be added to the growing polypeptide chain
C. The additon of new amino acid in the A site to the growing polypeptide chain is catalyzed by one of the enzymes that form the large ribosomal subunit
D. All of the above
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DNA polymerase involved in general DNA replication in eukaryotes is
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The length of DNA present in nucleosome core particle
A. 146 bp
B. 165 bp
C. 200 bp
D. None of the above
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The reduction of nitrate to nitrite in the cytosol is catalyzed by the enzyme
A. Nitrite reductase
B. Glutamine synthetase
C. Nitrate reductase
D. Glutamate dehydrogenase
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The term "gene" was coined by
A. Wilhelm Johannensen
B. Morgan
C. Benzer
D. William Bateson
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In clover leaf model of tR N A , ψ present in T ψ C loop represents
A. Pseudouridine or pseudouracil
B. Dihydrouridine or dihydrouracil (D-loop)
C. Both A and B
D. Uracil
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Which of the following steps are involved in the process of template preparation during DNA replication?
A. Unwinding of double helix
B. Breakage of hydrogen bonds
C. Coating of single stranded template to prevent them from reannealing
D. All of the above
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Because of base interactions, the outside of the helix is not smooth and it is termed as
A. Major groove
B. Minor groove
C. A and B both
D. None of the above
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Initiator codon (AUG) always encode the amino acid
A. Metheonine
B. N-formyl metheonine
C. Both A and B
D. Not code for any amino acid
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Which one of the following component of RNA polymerase is NOT common to both prokaryotes and eukaryotes?
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The number of bases per turn of the helix in A form DNA is
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Based on buoyant density gradient centrifugation, the mammalian genome is divided into five regions which are > 300 kbp in length, characterized by relatively homogenous compositions. These regions are
A. Isochores
B. Isozymes
C. Isocentre
D. All of the above
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