Hind II always cut DNA molecules by recognising a specific sequence of _________ base pairs.

[Biotechnology-Principles-and-Processes] [class-xii ]

• four
• five
• six
• eight
Correct Option: C  [ six ]

Remark: Hind II recognizes a specific sequence of six base pairs.

We know more than _________ restriction enzymes isolated from over 230 strains of bacteria today.

[Biotechnology-Principles-and-Processes] [class-xii ]

• 230
• 500
• 900
• 1200
Correct Option: C  [ 900 ]

Remark: More than 900 restriction enzymes have been isolated from over 230 strains of bacteria.

In the convention for naming restriction enzymes (e.g., EcoRI), the first letter comes from the _________ of the prokaryotic cell.

[Biotechnology-Principles-and-Processes] [class-xii ]

• species
• genus
• strain
• order
Correct Option: B  [ genus ]

Remark: The first letter comes from the genus (E from Escherichia).

In the convention for naming restriction enzymes (e.g., EcoRI), the second two letters come from the _________ of the prokaryotic cell.

[Biotechnology-Principles-and-Processes] [class-xii ]

• genus
• species
• strain
• order
Correct Option: B  [ species ]

Remark: The second two letters come from the species (co from coli).

In the restriction enzyme name EcoRI, the letter ‘R’ is derived from the name of the bacterial _________.

[Biotechnology-Principles-and-Processes] [class-xii ]

• genus
• species
• strain
• plasmid
Correct Option: C  [ strain ]

Remark: The letter ‘R’ is derived from the name of the strain (RY 13).

The Roman numbers following the names of restriction enzymes indicate the _________ in which the enzymes were isolated from that strain of bacteria.

[Biotechnology-Principles-and-Processes] [class-xii ]

• activity level
• molecular size
• order
• recognition site length
Correct Option: C  [ order ]

Remark: Roman numbers indicate the order in which the enzymes were isolated from that strain.

Restriction enzymes belong to a larger class of enzymes called _________.

[Biotechnology-Principles-and-Processes] [class-xii ]

• polymerases
• nucleases
• ligases
• proteases
Correct Option: B  [ nucleases ]

Remark: Restriction enzymes belong to the larger class of enzymes called nucleases.

Enzymes that remove nucleotides from the ends of the DNA are known as _________.

[Biotechnology-Principles-and-Processes] [class-xii ]

• endonucleases
• exonucleases
• ribonucleases
• DNA ligases
Correct Option: B  [ exonucleases ]

Remark: Exonucleases remove nucleotides from the ends of the DNA.

Enzymes that make cuts at specific positions within the DNA are known as _________.

[Biotechnology-Principles-and-Processes] [class-xii ]

• exonucleases
• endonucleases
• polymerases
• methylases
Correct Option: B  [ endonucleases ]

Remark: Endonucleases make cuts at specific positions within the DNA.

A restriction endonuclease cuts each of the two strands of the double helix at specific points in their _________ backbones.

[Biotechnology-Principles-and-Processes] [class-xii ]

• nitrogenous base
• hydrogen bond
• sugar-phosphate
• carbon
Correct Option: C  [ sugar-phosphate ]

Remark: The cut occurs at specific points in the sugar-phosphate backbones.