Question 1

Which of the following best describes the function of plasmids in bacterial cells?

Accepted Answer

Plasmids are circular DNA molecules that can replicate independently and often carry genes beneficial for survival, such as antibiotic resistance.

Question 2

What is the primary advantage of CRISPR-Cas9 technology over previous gene-editing methods?

Accepted Answer

It is relatively cheaper, more precise, and faster than previous methods.

Question 3

Which enzyme is responsible for cutting DNA at specific sequences during recombinant DNA technology?

Accepted Answer

Restriction enzyme

Question 4

During PCR, what is the purpose of the denaturation step?

Accepted Answer

To separate double-stranded DNA into single strands.

Question 5

A scientist wants to amplify a specific region of DNA from a small sample. Which technique should they use?

Accepted Answer

Polymerase Chain Reaction (PCR)

Question 6

Which of the following is NOT a typical application of PCR?

Accepted Answer

Separating DNA fragments by size

Question 7

In gel electrophoresis, why do smaller DNA fragments move faster through the gel?

Accepted Answer

They are slowed down less by the gel matrix.

Question 8

Which of the following is a real-world application of recombinant DNA technology in agriculture?

Accepted Answer

Producing modified corn to reduce pesticide use

Question 9

What is the role of guide RNA (gRNA) in the CRISPR-Cas9 system?

Accepted Answer

It guides the Cas9 enzyme to the target DNA sequence for cutting.

Question 10

Which of the following best explains why Escherichia coli is commonly used in molecular biology?

Accepted Answer

It can replicate plasmids and is easy to manipulate genetically.

Question 11

A patient is treated with a protein produced using recombinant DNA technology. Which process was most likely used to produce this protein?

Accepted Answer

Insertion of the human gene encoding the protein into bacterial cells, followed by protein extraction.

Question 12

Which of the following is a correct sequence of steps in a single PCR cycle?

Accepted Answer

Denaturation, annealing, extension

Question 13

If a DNA fragment is cut into three pieces by a restriction enzyme, how will these fragments appear on a gel after electrophoresis?

Accepted Answer

As three distinct bands, with the smallest fragment migrating the farthest.

Question 14

Which formula best represents the exponential amplification of DNA during PCR after $$n$$ cycles, starting with one molecule?

Accepted Answer

$$2^n$$

Question 15

A forensic scientist uses DNA fingerprinting to identify a suspect. Which molecular biology tool is most critical for this process?

Accepted Answer

Gel electrophoresis

Question 16

Which of the following statements about Cas9 is TRUE?

Accepted Answer

Cas9 is the enzyme that uses guide RNA to cut viral DNA.

Question 17

Which of the following is NOT a direct application of gene editing tools like CRISPR?

Accepted Answer

Separating DNA fragments by size

Question 18

Reverse transcriptase is unique because it synthesizes DNA from which template?

Accepted Answer

An RNA template

Question 19

Which of the following best describes the role of restriction enzymes in molecular cloning?

Accepted Answer

They cut DNA at specific recognition sequences.

Question 20

A researcher wants to identify the exact sequence of nucleotides in a gene. Which technique should they use?

Accepted Answer

DNA sequencing

Biotechnology and Recombinant DNA: Tools and Applications

Study Guide - Practice Questions