DNA Extraction and Analysis Quiz

Which of the following bases are classified as purines?

• Adenine and Cytosine

• Guanine and Thymine

• Adenine and Guanine

• Cytosine and Thymine

In DNA extraction, the purpose of using isopropanol or ethanol is to:

• Break down proteins

• Precipitate DNA

• Dissolve lipids

• Separate RNA from DNA

During phenol/chloroform extraction, nucleic acids are found in which layer after centrifugation?

• Organic (lower) layer

• Aqueous (upper) layer

• Interface layer

• Bound to phenol phase

Which of the following differentiates DNA from RNA?

• DNA contains ribose sugar while RNA contains deoxyribose

• DNA is single-stranded while RNA is double-stranded

• DNA contains thymine while RNA contains uracil

• Both contain uracil as a nitrogenous base

A researcher extracts DNA from banana using detergent, salt, and alcohol. The detergent function in this step is:

• To precipitate DNA

• To denature proteins

• To dissolve cell membranes by breaking lipids

• To stabilize DNA structure

A student observes smeared DNA bands on agarose gel electrophoresis after extraction from blood. The most likely cause is:

• Contamination with RNA

• Overloading of the gel with DNA

• Incomplete protein removal

• All of the above

Proteinase K is added during DNA extraction to:

• Digest polysaccharides

• Break down proteins and nucleases

• Precipitate DNA

• Enhance lipid dissolution

A farmer in Egypt uses Bt cotton to reduce pesticide use. The gene responsible for pest resistance is inserted using:

• Lipid nanoparticles

• Agrobacterium-mediated transformation

• CRISPR-Cas9 editing

• Electroporation

A patient’s tumor DNA is being sequenced to identify mutations for personalized therapy. The primary reason for DNA purification before sequencing is:

• To remove water

• To eliminate proteins and other contaminants that interfere with enzymes

• To increase DNA double helix stability

• To convert DNA to RNA for easier analysis

In the development of COVID-19 vaccines, synthetic mRNA was produced from DNA templates. This demonstrates which principle of biotechnology?

• Reverse transcription from RNA to DNA

• Use of recombinant DNA to generate coding sequences

• Gene silencing using siRNA

• DNA replication by DNA polymerase III