To make bacterial cells competent to take up DNA, they are treated with a specific concentration of a _________ cation, such as calcium.

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

• monovalent
• divalent
• trivalent
• tetravalent
Correct Option: B  [ divalent ]

Remark: Treatment is done with a divalent cation, such as calcium.

The heat shock step in making competent cells involves briefly placing them at _________.

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

• 0°C
• 37°C
• 42°C
• 100°C
Correct Option: C  [ 42°C ]

Remark: Cells are briefly placed at 42°C (heat shock).

In the method known as _________, recombinant DNA is directly injected into the nucleus of an animal cell.

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

• biolistics
• gene gun
• micro-injection
• heat shock
Correct Option: C  [ micro-injection ]

Remark: Micro-injection involves direct injection into the nucleus of an animal cell.

The method suitable for plants where cells are bombarded with high velocity micro-particles of gold or tungsten coated with DNA is known as _________.

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

• electroporation
• biolistics or gene gun
• micro-injection
• chemical treatment
Correct Option: B  [ biolistics or gene gun ]

Remark: This technique is known as biolistics or gene gun.

Recombinant DNA technology involves several steps, the first of which is the isolation of _________.

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

• a restriction enzyme
• desired DNA fragment
• genetic material (DNA)
• the vector
Correct Option: C  [ genetic material (DNA) ]

Remark: The process starts with the isolation of DNA.

To break open bacterial cells to release DNA and other macromolecules, the enzyme _________ is used.

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

• cellulase
• chitinase
• lysozyme
• protease
Correct Option: C  [ lysozyme ]

Remark: Lysozyme is used to treat bacterial cells.

To break open plant cells to release DNA and other macromolecules, the enzyme _________ is used.

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

• lysozyme
• cellulase
• chitinase
• ribonuclease
Correct Option: B  [ cellulase ]

Remark: Cellulase is used to treat plant cells.

To break open fungal cells to release DNA and other macromolecules, the enzyme _________ is used.

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

• cellulase
• lysozyme
• chitinase
• amylase
Correct Option: C  [ chitinase ]

Remark: Chitinase is used to treat fungal cells.

RNA can be removed from the DNA preparation by treatment with the enzyme _________.

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

• protease
• ribonuclease
• deoxyribonuclease
• ligase
Correct Option: B  [ ribonuclease ]

Remark: RNA is removed by treatment with ribonuclease.

Proteins can be removed from the DNA preparation by treatment with the enzyme _________.

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

• ribonuclease
• cellulase
• protease
• chitinase
Correct Option: C  [ protease ]

Remark: Proteins are removed by treatment with protease.