Biology

DNA and Genetics

1,095 Questions

DNA and genetics questions explore molecular biology, DNA replication, and genetic engineering techniques. These topics are essential for various competitive exams requiring a strong foundation in life sciences. Practice these questions to understand complex biological processes thoroughly.

DNA replication mechanismsGenetic engineering techniquesGene editing toolsPolymerase chain reactionDNA sequencing methods

DNA and Genetics Questions

Multiple choice

Full expression of lac operon requires

  1. lactose and cAMP

  2. allolactose and cAMP

  3. cAMP

  4. lactose
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Full expression of lac operon requires allolactose and cAMP. lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in E. coli and many other enteric bacteria.

Multiple choice

Which of the following processes is a DNA damage tolerance process?

  1. Tautomerism

  2. Depurination

  3. Deamination

  4. Slipped strand mispairing

  5. Translesion synthesis
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Translesion synthesis is a DNA damage tolerance process that allows the DNA replication machinery to replicate past DNA lesions, such as thymine dimers or AP sites.

Multiple choice

Identify the incorrect statement regarding recombinant DNA technology?

  1. Restriction enzymes are used to cut DNA molecule.

  2. Paul Berg’s developed the first rDNA molecule by gene splicing experiment.

  3. Gene cloning refers to the production of large number of copies of the gene.

  4. The mechanism of intake of DNA fragments from the surrounding medium by a cell is called transformation.

  5. The first successful transformation of rDNA was governed by Boyer and Cohen in 1969.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The first successful transformation of rDNA into a bacterium was governed by Boyer and Cohen in 1973.

Multiple choice

Which of the following is an incorrect statement?

  1. The synthesis of DNA from mRNA involves reverse transcriptase enzyme.

  2. Both Taq polymerase and Vent polymerase are thermostable DNA polymerases.

  3. Klenov is the product of enzymatic breakdown of DNA polymerase I involving cutting of DNA strand.

  4. Alkaline phosphatase enzyme is used to remove phosphate group from the 5’ end of DNA.

  5. Ligase enzyme is used to join two DNA molecules.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Klenow fragment is a large protein fragment, produced when DNA polymerase - I from E. coli is enzymatically cleaved by the protease subtilisin. The Klenow fragment was also the original enzyme used for greatly amplifying segments of DNA in the polymerase chain reaction (PCR) process. Restriction enzymes like- endonucleases are used to cut the DNA strand.

Multiple choice

Which antigenic particle present in the serum of individuals infected with the virus hepatitis B, contains both DNA and DNA polymerase?

  1. p7 nucleocapsid protein

  2. A spherical 22 nm particle

  3. Dane particle

  4. Tubular or filamentous 22 nm particle

  5. GP 120 envelope protein
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The virus particle consists an outer lipid envelope and an icosahedral nucleocapsid core composed of protein. These virions are 42 nm in diameter and are sometimes referred to as Dane particles. This is known as the Dane particle as it was discovered by Dane in 1970. The nucleocapsid encloses the viral DNA and a DNA polymerase that has reverse transcriptase activity.