---

Question 1:

What is the purpose of DNA Fragment Analysis?

A) To amplify DNA fragments
B) To determine the size of DNA fragments
C) To sequence the DNA fragments
D) To quantify DNA concentration

Show Answer

Explanation: The correct answer is B) To determine the size of DNA fragments. DNA Fragment Analysis is a technique used to determine the size of DNA fragments. It involves separating the DNA fragments based on their size using gel electrophoresis or capillary electrophoresis. By comparing the migration pattern of the unknown DNA fragments with known size standards, the size of the DNA fragments can be determined.

---

Question 2:

What is the principle behind DNA Fragment Analysis using gel electrophoresis?

A) Separation based on size and charge
B) Separation based on sequence
C) Amplification of DNA fragments
D) Introduction of labeled nucleotides

Show Answer

Explanation: The correct answer is A) Separation based on size and charge. DNA Fragment Analysis using gel electrophoresis relies on the principle of separating DNA fragments based on their size and charge. In this technique, DNA fragments are loaded into wells of an agarose gel and subjected to an electric field. The negatively charged DNA fragments migrate through the gel matrix towards the positively charged electrode, with smaller fragments moving faster and traveling farther than larger fragments. The separation is based on the differential mobility of the DNA fragments, which is influenced by their size and charge.

---

Question 3:

What is the main advantage of DNA Fragment Analysis using capillary electrophoresis over gel electrophoresis?

A) Higher resolution
B) Lower cost
C) Simpler setup
D) Longer separation time

Show Answer

Explanation: The correct answer is A) Higher resolution. DNA Fragment Analysis using capillary electrophoresis offers a higher resolution compared to gel electrophoresis. In capillary electrophoresis, DNA fragments are separated in a narrow capillary filled with a polymer matrix, and the separation is based on size and charge. The capillary format allows for better resolution of DNA fragments, particularly for fragments that are close in size. Capillary electrophoresis also offers higher sensitivity, faster run times, and automated data collection, making it a preferred method for DNA Fragment Analysis in many applications.

---

Question 4:

Which fluorescent dye is commonly used to label DNA fragments for DNA Fragment Analysis?

A) Ethidium bromide
B) SYBR Green
C) DAPI
D) Fluorescein

Show Answer

Explanation: The correct answer is B) SYBR Green. SYBR Green is a commonly used fluorescent dye for labeling DNA fragments in DNA Fragment Analysis. SYBR Green binds to double-stranded DNA and becomes fluorescent upon binding, allowing for the visualization and detection of DNA fragments during gel electrophoresis or capillary electrophoresis. The fluorescence emitted by the SYBR Green-labeled DNA fragments can be detected and quantified using appropriate imaging systems or instruments.

---

Question 5:

What can be inferred if multiple DNA fragments of the same size are observed in DNA Fragment Analysis?

A) PCR artifacts
B) Genetic mutations
C) DNA degradation
D) Heterozygosity

Show Answer

Explanation: The correct answer is D) Heterozygosity. If multiple DNA fragments of the same size are observed in DNA Fragment Analysis, it suggests the presence of heterozygosity. Heterozygosity refers to the presence of different alleles or DNA sequences at a particular locus in a diploid organism. The presence of multiple fragments of the same size indicates that the DNA sample contains different alleles or variants of the target region, which can be informative for genetic studies or diagnostic purposes.