Selected MCQ

Current Question
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 1
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.
Related Question 2
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 3
A female exhibits an X-linked recessive trait. What must be true of her parents’ genotypes?
  • A. Her father must have the trait, and her mother must be at least a carrier
  • B. Both parents must be affected
  • C. Only her mother is affected
  • D. Either parent could have the trait independently
Correct Answer: A
Explanation:
For a daughter to be homozygous for an X-linked recessive allele, her father must have the allele (so he is affected) and her mother must carry at least one mutant X.
Related Question 4
DNA methylation at CpG islands in gene promoters typically leads to:
  • A. Transcriptional activation
  • B. Transcriptional silencing
  • C. Increased mutation rate
  • D. Immediate DNA repair
Correct Answer: B
Explanation:
Methylation of cytosines in promoters condenses chromatin and represses transcription, silencing the gene.
Related Question 5
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.