Biology Inheritance / Variation & Genetics PMC 2020
PMDC Verified Question 70 of 94
Haemophilia A and B, color blindness and testicular feminization are example of:
A
X linked dominant traits
B
Y linked inheritance
C
X linked recessive traits
D
Pseudoautosomal traits
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: X linked recessive traits
Concept:

These disorders cluster together phenotypically because they follow the exact same chromosomal inheritance rules.

Solution:

  • Haemophilia A & B, red-green color blindness, and Testicular Feminization Syndrome (TFM) are all classic X-linked recessive traits.
  • They occur when an individual possesses exclusively mutated copies of the associated gene on their X chromosome(s).
  • Because males (XY) only have one X chromosome, they are much more frequently affected by these specific disorders than females (XX).


Why other options are incorrect:

  • X-linked dominant: Requires only one copy of the gene to express the trait (e.g., Hypophosphatemia), which is not the case for these.
  • Y-linked: Traits strictly passed from father to son (e.g., hypertrichosis of the ear).

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Previous Question All Inheritance / Variation & Genetics MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App