Biotechnology Principles and Processes

Which of the following techniques is primarily used to separate DNA fragments according to their size?

1. Polymerase Chain Reaction (PCR)
2. Gel electrophoresis
3. Transformation
4. DNA ligation

Which instrument is commonly used for large-scale production of recombinant proteins under controlled conditions?

1. Centrifuge
2. Autoclave
3. Bioreactor
4. Electrophoresis chamber

Which of the following statements about Agrobacterium tumefaciens is correct?

1. It is used as a cloning vector in bacteria only.
2. It naturally transfers DNA into plant cells through its Ti plasmid.
3. It produces restriction enzymes used in genetic engineering.
4. It is used only for animal cell transformation.

In PCR, the purpose of primers is to:

1. Cut DNA into fragments
2. Join DNA fragments
3. Provide a starting point for DNA synthesis
4. Remove RNA primers

Which of the following enzymes is used to amplify a specific DNA segment during the Polymerase Chain Reaction (PCR)?

1. DNA Ligase
2. Taq DNA Polymerase
3. Restriction Endonuclease
4. Reverse Transcriptase

The process of introducing recombinant DNA into a bacterial cell is known as:

1. Translation
2. Transformation
3. Transcription
4. Transduction

Which bacterium is most commonly used as the host organism in recombinant DNA technology?

1. Bacillus subtilis
2. Escherichia coli
3. Lactobacillus
4. Rhizobium

Which of the following is commonly used as a selectable marker in bacterial cloning vectors?

1. Insulin gene
2. Ampicillin resistance gene
3. Hemoglobin gene
4. Ribosomal RNA gene

Which feature of a cloning vector ensures that it can replicate independently inside the host cell?

1. Promoter
2. Origin of replication (ori)
3. Restriction site
4. Selectable marker

Which of the following is the correct sequence of major steps in recombinant DNA technology?

1. Isolation of DNA → Gene transfer → DNA amplification → Restriction digestion
2. Restriction digestion → Isolation of DNA → Gene transfer → Selection
3. Isolation of DNA → Restriction digestion → Ligation into vector → Transformation → Selection of recombinants
4. Transformation → Isolation of DNA → Ligation → Restriction digestion

The enzyme used to synthesize complementary DNA (cDNA) from messenger RNA is:

1. DNA ligase
2. RNA polymerase
3. Reverse transcriptase
4. Restriction endonuclease

In recombinant DNA technology, the term "competent cells" refers to cells that:

1. Divide very rapidly
2. Can readily take up foreign DNA
3. Produce restriction enzymes
4. Synthesize antibiotics

Which one of the following acts as the most commonly used cloning vector in recombinant DNA technology?

1. Ribosome
2. Plasmid
3. Mitochondrion
4. Lysosome

The enzyme DNA ligase is mainly responsible for:

1. Cutting DNA molecules
2. Joining DNA fragments by forming phosphodiester bonds
3. Synthesizing RNA from DNA
4. Unwinding the DNA double helix

Which of the following enzymes is commonly used to cut DNA at specific recognition sites during recombinant DNA technology?

1. DNA ligase
2. DNA polymerase
3. Restriction endonuclease
4. Reverse transcriptase