Transmission of X-Linked Characters
Inheritance of X-linked character is through-
- Male parent only
- Female parent only
- Both — Correct Answer
- None
Explanation:
Correct Answer: Both
X-linked characters can be inherited through both parents — a mother (XX) passes her X chromosomes to both sons and daughters, while a father (XY) passes his X chromosome to daughters only.
X-Linked Inheritance — Key Points
- Genes located on the X chromosome
- Mother (XX) → passes X to both sons and daughters
- Father (XY) → passes X to daughters only
- Therefore, inheritance is through both male and female parents
Criss-Cross vs. Non-Criss-Cross Inheritance of X-Linked Traits
| Type | Pattern | Example |
|---|---|---|
| Diagenic (criss-cross) | Father → Daughter → Grandson | X-linked recessive traits |
| Diandric (criss-cross) | Mother → Son → Granddaughter | X-linked recessive traits |
| Holandric (non-criss-cross) | Father → Son → Grandson | Y-linked traits (e.g., Hypertrichosis) |
| Hologenic (non-criss-cross) | Mother → Daughter → Granddaughter | Y-linked mitochondrial traits |
Examples of X-Linked Traits
- X-linked: Haemophilia, Colour blindness, Barred plumage in poultry (sex-linked)
- Y-linked: Hypertrichosis (excess hair on ear pinna), TDF (Testis-determining factor)
Why Other Options Are Wrong
- Male parent only → true for Y-linked (holandric) traits, not X-linked
- Female parent only → incomplete; fathers also pass X to daughters
- None → impossible; X-linked traits are inherited through normal Mendelian mechanisms
📚 About this Topic — Animal Genetics & Breeding
This multiple choice question is from Animal Genetics & Breeding, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Genetics & Breeding to strengthen your preparation.
