Selected MCQ

Current Question
The technique for producing monoclonal antibodies involves fusing a specific antibody-producing B cell with a myeloma cell (a cancer cell). This hybrid cell line is called a:
  • A. Bacteriophage
  • B. Hybridoma
  • C. Plasmid
  • D. Complement
Correct Answer: B
Explanation:
A hybridoma results from fusing a single B lymphocyte (which produces one antibody) with a myeloma cell, creating an immortal cell line that produces identical (monoclonal) antibodies.
Related Question 1
In flow cytometry, cells are labeled with fluorescent antibodies and passed in a stream through a laser. This technique primarily measures:
  • A. Cell size and internal complexity
  • B. DNA sequence variants
  • C. Protein structure by X-ray diffraction
  • D. Glycolytic activity
Correct Answer: A
Explanation:
Flow cytometry measures light scattering (size and granularity) and fluorescence from labeled markers, allowing rapid analysis of cell populations (size, complexity, marker expression).
Related Question 2
Monoclonal antibodies differ from polyclonal antibodies in that monoclonals:
  • A. Are produced by multiple B cell clones
  • B. Recognize multiple epitopes on the same antigen
  • C. Are derived from a single B cell clone and recognize a single epitope
  • D. Are less specific than polyclonals
Correct Answer: C
Explanation:
Monoclonal antibodies come from one B-cell clone, so they are identical and recognize one epitope. Polyclonal antibodies are produced by many B cells and recognize multiple epitopes on the antigen.
Related Question 3
What is the fundamental unit of heredity that occupies a specific locus on a chromosome?
  • A. Base pair
  • B. Gene
  • C. Chromatin
  • D. Nucleotide
Correct Answer: B
Explanation:
A gene is the hereditary unit at a chromosome locus. It consists of DNA sequences encoding a functional product (RNA or protein).
Related Question 4
Which plasmid-based technique is used to enrich and detect low-abundance mRNAs by reverse transcription into cDNA?
  • A. RFLP analysis
  • B. Northern blotting
  • C. RT-PCR (reverse-transcription PCR)
  • D. Affinity chromatography
Correct Answer: C
Explanation:
RT-PCR involves reverse-transcribing RNA to cDNA and then amplifying specific sequences by PCR. It is very sensitive for detecting low-abundance transcripts.
Related Question 5
Which assay would you use to detect and quantify a specific DNA sequence in a sample?
  • A. ELISA
  • B. Southern blot
  • C. Western blot
  • D. Gram staining
Correct Answer: B
Explanation:
A Southern blot uses a DNA probe to hybridize with a specific DNA sequence immobilized on a membrane, allowing detection of that sequence in the sample.