Selected MCQ

Current Question
In Western blotting, proteins are typically detected using:
  • A. DNA probes
  • B. RNA probes
  • C. Enzyme-linked antibodies
  • D. Radioactive amino acids
Correct Answer: C
Explanation:
Western blot uses antibodies (often enzyme-linked) that bind specific proteins on the membrane, allowing visualization via a colorimetric or chemiluminescent reaction.
Related Question 1
Which chromatography technique separates proteins primarily based on size using a gel matrix?
  • A. Ion-exchange chromatography
  • B. Gel filtration (size-exclusion) chromatography
  • C. Affinity chromatography
  • D. Reverse-phase chromatography
Correct Answer: B
Explanation:
Gel filtration chromatography (size-exclusion) separates proteins by size: larger molecules elute first because they enter fewer pores in the matrix, while smaller molecules elute later.
Related Question 2
Telomerase maintains chromosome ends by using a built-in RNA template. In which cells is telomerase typically active?
  • A. Most somatic cells
  • B. Germ cells and many cancer cells
  • C. Red blood cells
  • D. Neurons
Correct Answer: B
Explanation:
Telomerase is active in germline and stem cells (and reactivated in many cancers) to elongate telomeres, but is silent in most somatic cells.
Related Question 3
In gene therapy using a viral vector, what is a major concern related to using retroviruses?
  • A. They cannot infect human cells
  • B. They only integrate into mitochondrial DNA
  • C. Insertional mutagenesis by random integration into the host genome
  • D. They cannot carry large genes
Correct Answer: C
Explanation:
Retroviral vectors integrate randomly into the host genome, risking insertional mutagenesis (disrupting host genes), which can cause cancer or other issues.
Related Question 4
In tissue engineering, a scaffold material must typically be:
  • A. Non-biodegradable only
  • B. Biocompatible and biodegradable
  • C. Made of metal only
  • D. Radioactive
Correct Answer: B
Explanation:
Tissue scaffolds are usually biocompatible (non-toxic, no immune response) and biodegradable so that they eventually degrade as new tissue forms in the scaffold’s place.
Related Question 5
Which of the following is NOT typically controlled during industrial fermentation in a bioreactor?
  • A. Temperature
  • B. pH
  • C. Oxygen concentration
  • D. DNA sequence of the microorganism
Correct Answer: D
Explanation:
A, B, and C (temperature, pH, oxygen) are critical parameters controlled in fermentation. The chosen strain fixes the DNA sequence and is not a controlled parameter during the run.