Ligation of DNA

Q. What is the function of the DNA ligase?

1. It catalyses the formation of phosphodiester bonds between two DNA fragments
2. It catalyses hydrogen bond formation between two DNA strands
3. It is used to synthesise complementary DNA strand on DNA template
4. All of these

Q. The role of DNA ligase in the construction of a recombination DNA molecule is:

1. Ligation of all purine and pyrimidine bases
2. Formation of phosphodiester bond between two DNA fragments
3. Formation of hydrogen bonds between sticky ends of DNA fragments
4. Formation of hydrogen bonds between blunt ends

Q. Which of the following is not important for constructing a recombinant DNA?

1. DNA Ligase
2. Fragment of DNA
3. DNA Polymerase
4. Gene of interest

Q. Recombinant DNA technology can be accomplished only if we have the following key tools i.e., reaction enzymes, polymerase enzyme, ligases and vectors.
State the functions of:
(a) Ligases
(b) Restriction enzymes

Q. Choose the correct option regarding activity of different nucleases.

1. E1 - Endonuclease; E2 - Exonuclease; E3 - Restriction Endonuclease
2. E1 - Exonuclease; E2 - Endonuclease; E3 - Restriction Endonuclease
3. E1 - Exonuclease; E2 - Restriction Endonuclease; E3 - Endonuclease
4. E1 - Restriction Endonuclease ; E2 - Exonuclease; E3 - Endonuclease

Q. The DNA molecule to which the gene of interest is integrated for cloning is called

1. Template
2. Carrier
3. Transformer
4. Vector

Q. For ligation, the vector and the targetted gene should be cut by restriction enzyme.

1. same
2. any
3. random
4. different

Q. 3. What will happen, if the restriction enzymes have more than one recognition site in a vector?

Q.

DNA is unzipped twice ina cell.Name the 2 diifrent events which can occur and the enzyme s responisble for it?

Q. ............ are the enzymes used for cutting the DNA molecule into fragments. An example for this type of enzyme is Eco RI. What do EcoR and EcoI stands for?

Q. Which of the following enzymes will be used to insert genes at tet^R site of cloning vector pBR322-Sal 1 , Eco R 1 or Hind 3.why? how will the insertion affect the bacteria into which this rDNA is introduced?

Q. Write the sequence of DNA bases that the enzyme recognises. Mention the point at which the enzyme makes a cut in the DNA segment.

Q. The vector plasmid and the gene of interest that have been cut with the same restriction enzyme creating sticky ends are joined by .

1. DNA ligase
2. DNA polymerase
3. restriction enzyme
4. PCR

Q. Unwinding of DNA is done by

1. Topoisomerase
2. Exonuclease
3. Helicase
4. Ligase

Q. What is the function of DNA ligase in the formation of recombinant DNA?

1. It utilizes two ATP molecules.
2. It catalyzes the formation of phosphodiester bonds between two broken ends of DNA
3. It generally combines two DNA molecules with sticky ends.
4. All of the above

Q. The vector plasmid and the gene of interest that have been cut with the same restriction enzyme creating sticky ends are joined by .

1. DNA ligase
2. DNA polymerase
3. restriction enzyme
4. PCR

Q. Which of the following is not important for constructing a recombinant DNA?

1. DNA Polymerase
2. DNA Ligase
3. Gene of interest
4. Fragment of DNA

Q. For ligation, the vector and the targetted gene should be cut by restriction enzyme.

1. same
2. any
3. random
4. different