Matching Crosses in Genetics
Which of the following pair is/are correctly matched-
- Test cross = F1 hybrid x Homozygous recessive parent
- Back cross = F1 hybrid x Any of the Homozygous parent
- Out cross = F1 hybrid x Homozygous Dominant parent
- All the above — Correct Answer
Explanation:
Correct Answer: All the above
All three pairs are correctly matched as per standard genetics definitions:
| Cross Type | Definition | Correct? |
|---|---|---|
| Test cross | F₁ hybrid × Homozygous recessive parent (Tt × tt) | ✓ Correct |
| Back cross | F₁ hybrid × Any homozygous parent (Tt × TT or tt) | ✓ Correct |
| Out cross | F₁ hybrid × Homozygous dominant parent (Tt × TT) | ✓ Correct |
Types of Crosses — Summary
- Back cross = F₁ hybrid × any homozygous parent (either dominant or recessive)
- Test cross = F₁ hybrid × homozygous recessive (special form of back cross)
- Out cross = F₁ hybrid × homozygous dominant (special form of back cross)
- Back cross includes both Test cross and Out cross.
Monohybrid Cross Ratios
| Cross | F₂ Phenotypic Ratio | F₂ Genotypic Ratio |
|---|---|---|
| Monohybrid (TT × tt) | 3:1 | 1:2:1 |
| Dihybrid (YYRR × yyrr) | 9:3:3:1 | 1:2:1:2:4:2:1:2:1 |
📚 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.
