Inter-specific crosses are rare in nature and inter-generic crosses almost unknown .why?

Explanation

### Step-by-Step Solution:

1. **Definition of Inter-specific and Inter-generic Crosses**:
- Inter-specific crosses occur between individuals of different species within the same genus. Inter-generic crosses occur between individuals of different genera.

2. **Rarity of Inter-specific Crosses**:
- While inter-specific crosses can occur, they are rare in nature due to genetic differences between species. These differences can lead to issues such as incompatibility in gametes or developmental problems in the resulting offspring.

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