DNA Replication

Front

Find the incorrect statement about the Central Dogma of Molecular Biology:

It was proposed by Crick (1958)

,

Central Dogma initially stated the unidirectional flow of information from DNA to RNA and then Polypeptide

,

Temin and Baltimore discovered rhinoviruses having reverse transcriptase enzyme

,

Formation of DNA from RNA is also called Teminism

Back

Temin and Baltimore discovered rhinoviruses having reverse transcriptase enzyme

Front

Taylor etal (1957) experimented on which organism to prove semi conservative DNA replication?

Back

Vicia faba

Front

Which method did Taylor etal (1957) use in their experiment to prove semi conservative DNA replication?

• Radioactive Sulphur (S35)
• Radioactive Nitrogen (N15)
• Radioactive tritiated thymidine
• Radioactive Carbon (C14)

Back

Radioactive tritiated thymidine

Front

Which of the following statements is true regarding experiment on semi conservative replication by Meselson and Stahl?

• Grew colonies of E. coli in medium containing ammonium nitrate with heavy isotope of Nitrogen
• Grew colonies of E. coli in medium containing Sodium nitrate with heavy isotope of Nitrogen
• Grew colonies of E. coli in medium containing ammonium chloride with heavy isotope of Nitrogen
• Grew colonies of E. coli in medium containing Potassium chloride with heavy isotope of Nitrogen

Back

Grew colonies of E. coli in medium containing ammonium chloride with heavy isotope of Nitrogen

Front

Study the diagram carefully and find the in-correct statement:

DNA with N15-N15 settles at the bottom being heaviest

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There were no heavy DNA band (red) having only light and hybrid band in the 3rd tube due to semi conservative replication

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Each daughter has two newly synthesised DNA strands

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This experiment was performed by Meselson and Stahl

Back

Each daughter has two newly synthesised DNA strands

Front

Which statement about the Origin of Replication is not correct?

• Replication begins at a region of DNA having a particular nucleotide sequence called Autonomic Replication sequence (ARS)
• ARS is also called Origin of replication or 'Ori'
• Eukaryotes have single Ori whereas prokaryotes have multiple Ori
• Replication proceeds on both sides of Ori and is called Bidirectional replication

Back

Eukaryotes have single Ori whereas prokaryotes have multiple Ori

Front

Identify the incorrect statement about DNA replication: a) DNA of prokaryotes have single Replicon b) DNA of Eukaryotes have several Replicons c) Vector used in rDNA technology is for providing Ori d) Unidirectional replication is a common process

Back

Unidirectional replication is a common process

Front

Which statement is true about enzyme helicase?

Back

Helicase unwinds the DNA helix and breaks hydrogen bonds to unzip the two strands

Front

What is not found in Leading strand? Options: It grows in continuous fashion, Single primer is required, Grows in 5' to 3' direction, DNA ligase is required

Back

DNA ligase is required

Front

In the lagging strand, which statement is not true? Options: Continuous growth of DNA strand, Okazaki fragments are formed, DNA ligase used for joining DNA fragments, Separate RNA primer is required for each Okazaki fragment synthesis

Back

Continuous growth of DNA strand