Description : The enzyme which catalyzes the unwinding of DNA helix during replication is: (1) Primase (2) Topoisomerase (3) Helicase (4) DNA polymerase
Last Answer : (3) Helicase Explanation: A type of helicase enzyme called DNA helicase catalyzes the unwinding of the DNA helix at the time of replication. It uses the energy released through hydrolysis of ATP ( ... The enzyme is needed to separate the two strands of DNA also during transcription and DNA repair.
Description : There are special proteins that help to open up DNA double helix in front of the replication fork. These proteins are (a) DNA ligase (b) DNA topoisomerase I (c) DNA gyrase (d) DNA polymerase I.
Last Answer : (c) DNA gyrase
Description : The enzyme which catalyzes the unwinding of DNA helix during replication is: (1) Primase (2) Topoisomerase (3) Helicase (4) DNApolymerase
Last Answer : C option is the answer
Description : Negative supercoils are introduced in DNA by (A) Helicase (B) DNA ligase (C) DNA gyrase (D) DNA polymerase III holoenzyme
Last Answer : Answer : C
Description : DNA fragments are sealed by (A) DNA polymerase II (B) DNA ligase (C) DNA gyrase (D) DNA topoisomerase II
Last Answer : Answer : B
Description : The enzyme adds complementary bases to the DNA template strand during replication. a. Ligase b. Helicase c. DNA polymerase III d. RNA polymerase
Last Answer : d. RNA polymerase
Description : An eazyme produced by HIV that allows the integration of HIV DNA into the host cell's DNA is (1) Ligase (2) Integrase (3) Helicase (4) DNA gyrase
Last Answer : (2) Integrase Explanation: HIV's enzyme for inserting the DNA version of its genome into the host cell DNA is called its "integrase". HIV-1 integrase catalyzes the "cut-and-paste" action of ... to the clipped ends. It is also produced by viruses containing double-stranded DNAs for the same purpose.
Description : An eazyme produced by HIV that allows the integration of HIV DNA into the host cell’s DNA is : (1) Ligase (2) Integrase (3) Helicase (4) DNA gyrase
Last Answer : Integrase
Description : Indicate the enzyme(s) inhibited by fluoroquinolones: A. Both 'A' and 'C' B. Topoisomerase II C. Topoisomerase IV D. DNA gyrase
Last Answer : D. DNA gyrase
Description : From a DNA-RNA hybrid, DNA can be obtained by addition of (A) DNA B protein and ATP (B) Helicase and ATP (C) DNA topoisomerase I (D) Alkali
Last Answer : Answer : D
Description : Method of DNA replication in which two strands of DNA separate and synthesise new strands is called (a) dispersive (b) conservative (c) semi-conservative (d) non conservative
Last Answer : (a) dispersive
Description : Vinca alkaloids exert antitumor activity by: A. Activating topoisomerase II to cause breaks in DNA strands B. Crosslinking DNA strands C. Inhibiting DNA mediated RNA synthesis D. Inhibiting polymerization of tubulin to form intracellular microtubules
Last Answer : D. Inhibiting polymerization of tubulin to form intracellular microtubules
Description : Name the enzyme that facilitates opening of DNA helix during transcription. (a) DNA ligase (b) DNA helicase (c) DNA polymerase (d) RNA polymerase
Last Answer : b) DNA helicase
Description : Ciprofloxacin inhibits (A) DNA topisomerase II (B) DNA polymerase I (C) DNA polymerase III (D) DNA gyrase
Description : A consensus sequence on DNA, called TATA box, is the site for attachment of (A) RNA-dependent DNA polymerase (B) DNA-dependent RNA polymerase (C) DNA-dependent DNA polymerase (D) DNA topoisomerase II
Description : The region of DNA known as TATA BOX is the site for binding of (A) DNA polymerase (B) DNA topoisomerase (C) DNA dependent RNA polymerase (D) Polynucleotide phosphorylase
Description : The figure below shows three steps (A, B, C) of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents? A. B. C ds DNA 3 5 5 3 ... - extension in the presence of heat stable DNA polymerase (d) A - annealing with two sets of primers
Last Answer : (c) C - extension in the presence of heat stable DNA polymerase
Description : Given below is a sample of a portion of DNA strand giving the base sequence on the opposite strands. What is so special shown in it? 5′ _____ GAATTC _____ 3′ 3′ _____ CTTAAG _____ 5′ (a) ... completed (b) Deletion mutation (c) Start codon at the 5′ end (d) Palindromic sequence of base pairs
Last Answer : (d) Palindromic sequence of base pairs
Description : In the semiconservative method of replication a. Both parent strands are degraded. b. One parent strand is conserved in each of the the new dna. c. Both parent strands reform with one another. d. Okazaki fragments form both of the new molecules of DNA.
Last Answer : b. One parent strand is conserved in each of the the new dna.
Description : Function of DNA polymerase during DNA replication. -Biology
Last Answer : answer:
Description : Choose the correct pair from the following. (a) Ligases - Join the two DNA molecules (b) Polymerases - Break the DNA into fragments (c) Nucleases - Separate the two strands of DNA (d) Exonucleases - Make cuts at specific positions within DNA
Last Answer : (a) Ligases - Join the two DNA molecules
Description : What is the role of DNA polymerase in DNA replication? -Biology
Description : Template-directed DNA synthesis occurs in all the following except (A) The replication fork (B) Polymerase chain reaction (C) Growth of RNA tumor viruses (D) Expression of oncogenes
Description : Template-directed DNA synthesis occurs in all the following except (A) The replication fork (B) Polymerase chain reaction (C) Growth of RNA tumor viruses (D) Expression of oneogenes
Description : DNA contains some palindromic sequences which (A) Mark the site for the formation of replication forks (B) Direct DNA polymerase to turn back to replicate the other strand (C) Are recognized by restriction enzymes (D) Are found only in bacterial DNA
Description : Replication of nuclear DNA in mammals is catalysed by (A) DNA polymerase α (B) DNA polymerase β (C) DNA polymerase γ (D) DNA polymerase III
Last Answer : Answer : A
Description : 3’→5’ Exonuclease activity of DNA polymerase I (A) Removes ribonucleotides (B) Adds deoxyribonucleotides (C) Corrects errors in replication (D) Hydrolyses DNA into mononucleotides
Description : In DNA replication the enzyme required in the first step is (A) DNA directed polymerase (B) Unwinding proteins (C) DNA polymerase (D) DNA ligase
Description : At a chromosome replication fork, the lagging strand consists of__ That is joined by___. a. RNA sequences; DNA ligase b. Okazaki Fragments; RNA Polymerase c. RNA sequences; ribosomes d. Okazaki fragments; DNA ligase
Last Answer : d. Okazaki fragments; DNA ligase
Description : After formation of replication fork (A) Both the new strands are synthesized discontinuously (B) One strand is synthesized continuously and the other discontinuously (C) Both the new strands are synthesized continuously (D) RNA primer is required only for the synthesis of one new strand
Description : Viropexis takes place in the phagocytic vacuoles and is due to the action of Enzymes A- DNA gyrase B- lysosomal protease C- lysosomal lipase D- all of these
Last Answer : lysosomal protease
Description : 1. Bacteria protect themselves from viruses by fragmenting viral DNA with a. Ligase b. Endonuclease c. Exonuclease d. Gyrase
Last Answer : Ans: Endonuclease.
Description : Helicase and DNAB protein cause (A) Rewinding of DNA and require ATP as a source of energy (B) Rewinding of DNA but do not require any source of energy (C) Unwinding of DNA and require ATP as a source of energy (D) Unwinding of DNA but do not require any source of energy
Description : Enzyme which can break and seal the DNA strand a) Topoisomease II (b) Helicase (c) Primase (d) Restriction endonuclease
Last Answer : a) Topoisomease II
Description : DNA topoisomerase I of E. coli catalyses (A) Relaxation of negatively supercoiled DNA (B) Relaxation of positively supercoiled DNA (C) Conversion of negatively supercoiled DNA into positively supercoiled DNA (D) Conversion of double helix into supercoiled DNA
Description : Choose the correct statement about topotecan: A. It is a DNA topoisomerase I inhibitor which causes single strand DNA breaks B. It is a cell cycle specific anticancer drug C. It is a COMT-inhibitor used in advanced parkinsonism D. Both 'A' and 'B' are correc
Last Answer : D. Both 'A' and 'B' are correct
Description : During transcription, do both strands of DNA get transcribed into a double stranded RNA molecule?
Last Answer : No. RNA is single stranded and is transcribed from only one of the DNA strands. DNA replication does make copies of both strands.
Description : $ The two strands of DNA run in an antiparallel directions DNA is formed of Deoxyribose sugar. Phosphorus and nitrogen bases called purines and pyrimi
Last Answer : $ The two strands of DNA run in an antiparallel directions DNA is formed of Deoxyribose sugar. Phosphorus and ... wrong D. If both As and R are wrong.
Description : In a cell the tangled long strands of DNA form the?
Last Answer : In a cell, the tangles of long strands of DNA form the
Description : What is long uncoiled strands of DNA in animal cell?
Last Answer : Need answer
Description : In sticky ends produced by restriction endonucleases (A) The 2 strands of DNA are joined to each other (B) The DNA strands stick to the restriction endonuclease (C) The ends of a double stranded fragment are overlapping (D) The ends of a double stranded fragment are non overlapping
Description : The unwound strands of DNA are held apart by (A) Single strand binding protein (B) Double strand binding protein (C) Rep protein (D) DNAA protein
Description : Which of the following statement(s) is/are true concerning DNA? a. DNA is contained only in the nucleus of the cell b. DNA strands are encoded by the sequence of four bases-adenine, guanine, cytosine ... DNA is the intron, a sequence of three bases d. There are an infinite number of possible codons
Last Answer : Answer: a The genetic blueprint of an organism is carried in the nucleus of every cell, encoded by the sequence of four bases-adenine, guanine, cytosine and thymine, which together make up ... codons. Sixty-one of these code for amino acids and three are termination signals called stop codons
Description : The two strands of the DNA double helix are held together by (a) Hydrogen bonds (b)C=C double bonds (c) Hydrophobic bonds (d) Peptide bonds
Last Answer : Ans:(a)
Description : Give reason: The two strands of DNA molecule are complementary to each other but are not identical.
Last Answer : The two strands of DNA are not identical because the nitrogenous bases are different in pairing. A purine base of one polynucleotide chain always pairs with a pyramidine base on the other. Adenine (A) pairs ... and Cytosine (C) pairs with Thymine (T). Hence the two strands of DNA are complementary.
Description : Following statements describe the characteristics of the enzyme restriction endonuclease. Identify the incorrect statement. (a) The enzyme recognises a specific palindromic nucleotide sequence in the DNA. (b) ... (d) The enzyme cuts the sugar-phosphate backbone at specific sites on each strand.
Last Answer : (c) The enzyme binds DNA at specific sites and cuts only one of the two strands.
Description : Escherichia coli fully labelled with 15N is allowed to grow in 14N medium. The two strands of DNA molecule of the first generation bacteria have (a) different density and do not resemble parent DNA ( ... DNA (c) same density and resemble parent DNA (d) same density but do not resemble parent DNA.
Last Answer : (c) same density and resemble parent DNA
Last Answer : (a) different density and do not resemble parent DNA
Description : Antiparallel strands of a DNA molecule means that (a) one strand turns clockwise (b) one strand turns anti-clockwise (c) the phosphate groups of two DNA strands, at their ends, share the same position (d) the phosphate groups at the start of two DNA strands are in opposite position (pole).
Last Answer : (d) the phosphate groups at the start of two DNA strands are in opposite position (pole).
Description : n the DNA molecule, (a) the proportion of adenine in relation to thymine varies with the organism (b) there are two strands which run anti- parallel-one in 5′ → 3′ direction and other in 3′ → ... is not always equal (d) there are two strands which run parallel in the 5′ → 3′ direction.
Last Answer : (b) there are two strands which run anti- parallel-one in 5′ → 3′ direction and other in 3′ → 5′