Selected MCQ

Current Question
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 1
Which cell cycle checkpoint is specifically responsible for preventing the onset of anaphase until all chromosomes are properly attached to the spindle apparatus?
  • A. G1/S checkpoint
  • B. G2/M checkpoint
  • C. Spindle assembly (metaphase) checkpoint
  • D. DNA damage checkpoint
Correct Answer: C
Explanation:
The spindle assembly (metaphase) checkpoint delays anaphase until every chromosome is correctly attached to the mitotic spindle, ensuring accurate chromosome segregation.
Related Question 2
Which term describes genes that are located on the same chromosome and inherited together more often than by chance?
  • A. Linked genes
  • B. Epistatic genes
  • C. Polygenic genes
  • D. Independent genes
Correct Answer: A
Explanation:
Linked genes are near each other on the same chromosome. They tend to be inherited together, and their recombination frequency is less than 50%.
Related Question 3
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.
Related Question 4
In Southern blotting, what type of probe is used to detect specific DNA sequences?
  • A. DNA probe labeled with a reporter
  • B. RNA probe labeled with a reporter
  • C. Protein probe labeled with antibody
  • D. Carbohydrate probe
Correct Answer: A
Explanation:
Southern blot uses a labeled single-stranded DNA (or RNA) probe complementary to the target DNA sequence, hybridizing to it on the membrane.
Related Question 5
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.