Which one(s) is correct -.

Options

A. Directional selection favours one extreme form over the other extreme and over intermediate forms of a trait.
B. Stabilizing selection favours intermediate forms of a trait
C. Disruptive selection favours both extreme forms of a trait.
D. All of the above

Answer

To determine which options regarding types of natural selection are correct, we will analyze each option based on the definitions and characteristics of directional, stabilizing, and disruptive selection.

### Step-by-Step Solution:

1. **Understanding Directional Selection**:
- Directional selection occurs when one extreme phenotype is favored over others, causing a shift in the population's traits in one direction.
- **Conclusion**: Option one stating that "Directional Selection Favors one extreme form over the other extreme and over intermediate forms of a trait" is correct.

2. **Understanding Stabilizing Selection**:
- Stabilizing selection favors the intermediate variants of a trait and acts against extreme phenotypes. This leads to a reduction in variation and maintains the status quo for a particular trait.
- **Conclusion**: Option two stating that "Stabilizing Selection Favors intermediate forms of a trait" is also correct.

3. **Understanding Disruptive Selection**:
- Disruptive selection favors both extreme phenotypes over the intermediate forms. This can lead to the emergence of two or more contrasting phenotypes in the population.
- **Conclusion**: Option three stating that "Disruptive Selection Favors both extreme forms of a trait" is correct as well.

### Final Conclusion:
All three options are correct:
- Option 1: Directional Selection favors one extreme form.
- Option 2: Stabilizing Selection favors intermediate forms.
- Option 3: Disruptive Selection favors both extreme forms.