Which cross is formed by crossing an F1 back to a parent breed?

• A. Backcross
• B. Outcross
• C. Inbreeding
• D. Allcross

Answer: (A)

Backcrossing is when you take the first-generation hybrid and mate it back to one of the original parent breeds. This reintroduces more genes from that parent, so the offspring resemble that parent more closely than the F1 did. In practical terms, you’re biasing the next generation toward that parent’s traits, typically resulting in about 75% of that parent’s genetic influence and 25% from the other parent. This is useful for reinforcing a desired trait from one parent while testing how it behaves in the hybrid background.

Crossing an F1 to an unrelated individual would be an outcross, which doesn’t bias toward a single parent. Inbreeding involves mating closely related individuals to increase homozygosity and consanguinity. The term allcross isn’t a standard concept in this context.