Unsaturated fatty acids have
(a) high melting point
(b) one or more double bonds
(c) oleic acid
(d) palmitic acid

Options

A. high melting point
B. one or more double bonds
C. oleic acid
D. palmitic acid

Answer

To determine which of the options correctly describes unsaturated fatty acids, we can analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Unsaturated Fatty Acids**:
- Unsaturated fatty acids are defined as fatty acids that contain one or more double bonds between carbon atoms in their hydrocarbon chain.

2. **Analyzing Option (a)**:
- **High Melting Point**: Unsaturated fatty acids generally have lower melting points compared to saturated fatty acids due to the presence of double bonds, which create kinks in the fatty acid chain, preventing tight packing.
- **Conclusion**: This option is incorrect.

3. **Analyzing Option (b)**:
- **One or More Double Bonds**: This is the defining characteristic of unsaturated fatty acids. They can be classified as:
- Monounsaturated (one double bond)
- Polyunsaturated (multiple double bonds)
- **Conclusion**: This option is correct.

4. **Analyzing Option (c)**:
- **Oleic Acid**: Oleic acid is a well-known unsaturated fatty acid, specifically a monounsaturated fatty acid, as it contains one double bond.
- **Conclusion**: This option is correct.

5. **Analyzing Option (d)**:
- **Palmitic Acid**: Palmitic acid is a saturated fatty acid, which means it does not contain any double bonds in its structure.
- **Conclusion**: This option is incorrect.

### Final Answer:
The correct options that describe unsaturated fatty acids are:
- (b) one or more double bonds
- (c) oleic acid