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MCQOPTIONS
This section includes 14620 Mcqs, each offering curated multiple-choice questions to sharpen your NEET knowledge and support exam preparation. Choose a topic below to get started.
| 4701. |
In a mutational event, when adenine is replaced by guanine, it is a case of [CBSE PMT 2004] |
| A. | Transition |
| B. | Transversion |
| C. | Frameshift mutation |
| D. | Transcription |
| Answer» B. Transversion | |
| 4702. |
Which is not correctly matched [BHU 2003] |
| A. | Lipase - Hydrolysis of fats |
| B. | Isomerases - Joining of similar substrate and management of substrate |
| C. | Polymerase - Chain elongation |
| D. | DNA ligase - Breaks DNA strand into two segments |
| Answer» E. | |
| 4703. |
c-DNA can be formed by [DPMT 2003] |
| A. | Transaminase |
| B. | DNA ligase |
| C. | RNA dependent DNA polymerase |
| D. | DNA dependent DNA polymerase |
| Answer» D. DNA dependent DNA polymerase | |
| 4704. |
What is false about t RNA [AIIMS 2003] |
| A. | It binds with an amino acid at it 5' end |
| B. | It has five double stranded regions |
| C. | It has a codon at one end which recognizes the anticodon on messenger RNA |
| D. | It looks like clover leaf in the three dimensional structure |
| Answer» B. It has five double stranded regions | |
| 4705. |
The enzyme DNA polymerase was discovered by [Kerala CET 2003] |
| A. | Kornberg |
| B. | Okazaki |
| C. | Waston and Crick |
| D. | Jacob and Monod |
| Answer» B. Okazaki | |
| 4706. |
The specific DNA sequence where Eco R1 cuts is [Kerala CET 2003; Orissa JEE 2004] |
| A. | \[\underset{\text{TAAGCT}}{\mathop{\text{ATTCGA}}}\,\]. |
| B. | \[\underset{\text{CTTAAG}}{\mathop{\text{GAATTC}}}\,\] |
| C. | \[\begin{align} & GCTTAA \\ & CGAATT \\ \end{align}\] |
| D. | \[\begin{align} & GTTCAA \\ & CAAGTT \\ \end{align}\] |
| Answer» C. \[\begin{align} & GCTTAA \\ & CGAATT \\ \end{align}\] | |
| 4707. |
Which site of a t-RNA molecule hydrogen bonds to a m-RNA molecule [MP PMT 1993, 2002] |
| A. | Codon |
| B. | Anticodon |
| C. | 5¢ end of the t-RNA molecule |
| D. | 3¢ end of the t-RNA molecule |
| Answer» C. 5¢ end of the t-RNA molecule | |
| 4708. |
Eukaryotic RNA polymerase III catalyse the synthesis of [Kerala CET 2003] |
| A. | m RNA |
| B. | t RNA |
| C. | 18.5 rRNA |
| D. | Introns |
| Answer» C. 18.5 rRNA | |
| 4709. |
It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for genetic material. This is written by [Kerala CET 2003] |
| A. | Meselson and Stahl |
| B. | Archibold Garrod |
| C. | Severo Ochoa |
| D. | Watson and Crick |
| Answer» E. | |
| 4710. |
Exon part of m-RNAs has code for [CBSE PMT 2002] |
| A. | Protein |
| B. | Lipid |
| C. | Phospholipid |
| D. | Carbohydrate |
| Answer» B. Lipid | |
| 4711. |
The enzyme that breaks \[{{H}_{2}}\] bonds in DNA is [Kerala CET 2002] |
| A. | Helicase |
| B. | Topoisomerase |
| C. | Ligase |
| D. | Polymerase |
| Answer» B. Topoisomerase | |
| 4712. |
Which one of the following peak absorption of ultraviolet light by heterocyclic bases (Nitrogen bases) [BHU 2000] |
| A. | 1500 nm |
| B. | 26 nm |
| C. | 75 nm |
| D. | 260 nm |
| Answer» E. | |
| 4713. |
The substance that acts as connecting link between two generations is [RPMT 1997] |
| A. | Ribonucleic acid |
| B. | Deoxyribonucleic acid |
| C. | Nucleoplasm |
| D. | Ribonucleic acid + Deoxyribonucleic acid |
| Answer» C. Nucleoplasm | |
| 4714. |
Which of the following is nongenetic, which is utilised for protein synthesis [AIIMS 1998] |
| A. | DNA |
| B. | zRNA |
| C. | mRNA |
| D. | None of these |
| Answer» D. None of these | |
| 4715. |
Which of the following RNAs picks up specific amino acid (from amino acid pool) in the cytoplasm to ribosome during protein synthesis [AIIMS 1998; CBSE PMT 1997] |
| A. | tRNA |
| B. | mRNA |
| C. | rRNA |
| D. | All of these |
| Answer» B. mRNA | |
| 4716. |
Restriction endonucleases are [CBSE PMT 1998] |
| A. | Synthesized by bacteria |
| B. | Present in mammalian cells for degradation of DNA |
| C. | Used in genetic engineering |
| D. | Used for in vitro DNA synthesis |
| Answer» D. Used for in vitro DNA synthesis | |
| 4717. |
The chemical knives of DNA are [CBSE PMT 1998] |
| A. | Ligases |
| B. | Polymerases |
| C. | Endonucleases |
| D. | Transcriptases |
| Answer» D. Transcriptases | |
| 4718. |
The length of a helix of DNA is |
| A. | \[10\overset{o}{\mathop{A}}\,\] |
| B. | \[20\overset{o}{\mathop{A}}\,\] |
| C. | \[30\overset{o}{\mathop{A}}\,\] |
| D. | \[34\overset{o}{\mathop{A}}\,\] |
| Answer» E. | |
| 4719. |
Recombinant DNA is achieved by cleaving the pro-DNAs by [CBSE PMT 1998] |
| A. | Primase |
| B. | Exonucleases |
| C. | Ligase |
| D. | Restriction endonuclease |
| Answer» E. | |
| 4720. |
The successive nucleotides of RNA are covalently linked through or antiparallel [CPMT 1999; JIPMER 2001; MP PMT 2001] |
| A. | Glycosidic bonds |
| B. | Phosphodiester bonds |
| C. | Hydrogen bonds |
| D. | None of these |
| Answer» C. Hydrogen bonds | |
| 4721. |
What is the type of coiling in DNA [MP PMT 1999] |
| A. | Right-handed |
| B. | Left-handed |
| C. | Zig-Zag |
| D. | Opposite |
| Answer» B. Left-handed | |
| 4722. |
Non-genetic RNA is of [MP PMT 1999, 2000] |
| A. | Two types |
| B. | Three types |
| C. | Only one type |
| D. | None of these |
| Answer» C. Only one type | |
| 4723. |
mRNA is a polymer of [MP PMT 1997] |
| A. | Deoxyribonucleosides |
| B. | Ribonucleosides |
| C. | Deoxyribonucleotides |
| D. | Ribonucleotides |
| Answer» E. | |
| 4724. |
Okazaki fragments are synthesised on [CPMT 2005] |
| A. | Leading strands of DNA only |
| B. | Lagging strands of DNA only |
| C. | Both leading and lagging strands of DNA |
| D. | Complementary DNA |
| Answer» C. Both leading and lagging strands of DNA | |
| 4725. |
Nobel prize winner E.W. Sutherland demonstrated |
| A. | Mechanism of action of cAMP |
| B. | tRNA |
| C. | Operon model |
| D. | mRNA |
| Answer» B. tRNA | |
| 4726. |
Which one statement regarding "Okazaki fragment'' is correct |
| A. | These are double helical fragments of DNA |
| B. | These are single stranded fragments of DNA |
| C. | These are fragments of mRNA |
| D. | These are fragments of tRNA |
| Answer» C. These are fragments of mRNA | |
| 4727. |
The bacterial genome contains [MP PMT 1996; BHU 2002] |
| A. | DNA and histone |
| B. | DNA or histone |
| C. | DNA without histone |
| D. | Neither DNA nor histone |
| Answer» D. Neither DNA nor histone | |
| 4728. |
If an isolated strain of DNA is kept at\[82-90{}^\circ C\], then [CPMT 1991, 95] |
| A. | It changes into RNA |
| B. | It divides into one million pieces |
| C. | No effect |
| D. | It uncoils into helixes |
| Answer» E. | |
| 4729. |
DNA is transcribed by some viral RNA using the enzyme [MP PMT 1996] |
| A. | DNA polymerase |
| B. | Reverse transcriptase |
| C. | Endonuclease |
| D. | Ligase |
| Answer» C. Endonuclease | |
| 4730. |
Ribosomal RNA is synthesised in [MP PMT 1996] |
| A. | Nucleolus |
| B. | Nucleosome |
| C. | Ribosome |
| D. | Lysosome |
| Answer» B. Nucleosome | |
| 4731. |
Okazaki segments are formed during [CBSE PMT 1996] |
| A. | Replication |
| B. | Transduction |
| C. | Transcription |
| D. | Translation |
| Answer» B. Transduction | |
| 4732. |
Mode of DNA replication in E. coli is [CPMT 2005] |
| A. | Conservative and unidirectional |
| B. | Semi conservative and unidirectional |
| C. | Conservative and bidirectional |
| D. | Semi conservative and bidirectional |
| Answer» E. | |
| 4733. |
The A/U and G/U ratio in RNA is |
| A. | \[\ne 0\] |
| B. | |
| C. | |
| D. | None of these |
| Answer» B. | |
| 4734. |
Eukaryotes differ from prokaryotes in the mechanism of DNA replication due to [BHU 1994] |
| A. | Different enzymes (instead of same enzyme) for synthesis of lagging and leading strands |
| B. | Discontinuous rather than semidiscontinuous replication |
| C. | Use of DNA primers rather than RNA primers |
| D. | Unidirectional rather than bidirectional replication |
| Answer» C. Use of DNA primers rather than RNA primers | |
| 4735. |
The enzyme which can cut molecules of DNA into segments is known as [CPMT 1995; MP PMT 1995; BHU 1995; CBSE PMT 2001; Orissa PMT 2002; Kerala CET 2003] |
| A. | DNA polymerase |
| B. | DNA ligase |
| C. | Restriction enzyme |
| D. | DNA gyrase |
| Answer» D. DNA gyrase | |
| 4736. |
Phosphorus is present in [J&K CET 2005] |
| A. | Protein |
| B. | DNA |
| C. | RNA |
| D. | Both DNA and RNA |
| Answer» E. | |
| 4737. |
The mean diameter of DNA double helix is |
| A. | \[20\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| B. | \[3.4\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| C. | \[4.5\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| D. | \[10\overset{\text{o}}{\mathop{\text{A}}}\,\] |
| Answer» B. \[3.4\overset{\text{o}}{\mathop{\text{A}}}\,\] | |
| 4738. |
Watson and Crick are known for their discovery that DNA [CPMT 1979; BHU 1980; DPMT 1983; MP PMT 1995; J&K CET 2002; BVP 2004] |
| A. | Is a single stranded helix |
| B. | Contains deoxyribose only |
| C. | Is a double stranded helix |
| D. | Synthesizes rRNA |
| Answer» D. Synthesizes rRNA | |
| 4739. |
A nucleoside differs from a nucleotide in not having [MP PMT 1995; J&K CET 2002] |
| A. | Phosphate |
| B. | Sugar |
| C. | Nitrogen base |
| D. | Phosphate and sugar |
| Answer» B. Sugar | |
| 4740. |
Purines of DNA are represented by [CPMT 1980; MP PMT 1986; CBSE PMT 1996; J&K CET 2002] |
| A. | Uracil and thymine |
| B. | Guanine and adenine |
| C. | Uracil and cytocine |
| D. | Thymine and cytocine |
| Answer» C. Uracil and cytocine | |
| 4741. |
DNA is methylated at [Orissa JEE 2005] |
| A. | A-residue |
| B. | G-residue |
| C. | T-residue |
| D. | C-residue |
| Answer» D. C-residue | |
| 4742. |
If the DNA strand has the nitrogenous base sequence ATTGCC, the mRNA will have [Manipal 1995; DPMT 2003; Kerala 2004] |
| A. | ATTGCA |
| B. | ATCGCC |
| C. | UGGACC |
| D. | UAACGG |
| Answer» E. | |
| 4743. |
Ribozyme is [BHU 1995] |
| A. | RNA without sugar |
| B. | RNA without phosphate |
| C. | RNA having enzymic activity |
| D. | RNA with extra phosphate |
| Answer» D. RNA with extra phosphate | |
| 4744. |
Okazaki fragments are joined in 3 correct sequence by [Kerala PMT 2005] |
| A. | DNA polymerase |
| B. | DNA ligase |
| C. | RNA polymerase |
| D. | Primase (e) Helicase |
| Answer» C. RNA polymerase | |
| 4745. |
If the DNA codons are ATG ATG ATG and a cytosine base is inserted at the beginning, which of the following will result [CBSE PMT 1995] |
| A. | A non-sense mutation |
| B. | CA TGA TGA TG |
| C. | CAT GAT GAT G |
| D. | C ATG ATG ATG |
| Answer» D. C ATG ATG ATG | |
| 4746. |
DNA replication is aided by [AFMC 1995; BCECE 2005] |
| A. | DNA polymerase only |
| B. | DNA ligase only |
| C. | Both DNA polymerase and ligase |
| D. | RNA polymerase |
| Answer» D. RNA polymerase | |
| 4747. |
Replication of DNA is in [Pb. PMT 1999; MP PMT 2001; Haryana PMT 2005] |
| A. | \[3'\to 5'\]direction |
| B. | \[2'\to 5'\]direction |
| C. | Both \[3'\to 5'\]direction and \[5'\to '\]direction |
| D. | None of these |
| Answer» D. None of these | |
| 4748. |
A model that relates repetitive DNA sequences and their transcripts of regulation in eukaryotes was proposed by |
| A. | Jacob and Monad |
| B. | Britton and Davidson |
| C. | Nilsson Ehle |
| D. | H.J. Muller |
| Answer» C. Nilsson Ehle | |
| 4749. |
Who among the following scientists developed cytochemical technique for the presence of DNA |
| A. | Johannsen |
| B. | Feulgen and Rossenbeck |
| C. | McClintock |
| D. | M.H.F. Wilkins |
| Answer» C. McClintock | |
| 4750. |
Catalytic property of RNA was discovered by |
| A. | Altmann and Bend |
| B. | Ochoa and Korenberg |
| C. | Altmann and Cock |
| D. | Fuelgen and Beherence |
| Answer» D. Fuelgen and Beherence | |