Two-Breed Rotational Crossing System

Correct Answer: 2-way Rotational Cross / Criss-cross

From the notes: The system of mating in which 2 breeds are crossed alternatively = 2-way rotational cross / Criss-cross.

Note on Terminology

'Criss-cross' has two different usages in genetics:

• In breeding systems: Criss-cross = 2-breed rotational crossing system — breeds A and B are used alternately as sires
• In sex-linked inheritance: Criss-cross inheritance = X-linked trait passed from father to daughter to grandson (or mother to son to granddaughter)

Key Fact

Maintenance of hybrid vigour in a cattle herd is done by rotational crossing. Minimum breeds for rotational crossing = TWO (2-way rotational / criss-cross).