Essential whrols of a flowers are

Options

A. Calyx and Corolla
B. Corolla and Gynoecium
C. Androecium and Gynoecium
D. All of the above

Answer

### Step-by-Step Solution:

1. **Understanding Flower Structure**: A flower is the reproductive unit of flowering plants. It consists of four main parts: calyx, corolla, androsium, and gynosium.

2. **Identifying Essential and Accessory Parts**:
- The **accessory parts** of a flower are the calyx and corolla.
- The **essential parts** of a flower are the androsium and gynosium.

3. **Defining Each Part**:
- **Calyx**: This is the outermost part of the flower, usually green, and serves as a protective structure during the bud stage.
- **Corolla**: This part is often colorful and attracts pollinators. It can be various colors, but is typically bright to attract insects.
- **Androsium**: This is the male reproductive part of the flower, consisting of stamens, which are made up of anthers and filaments.
- **Gynosium**: This is the female reproductive part of the flower, consisting of the stigma, style, and ovary.

4. **Conclusion**: The essential whorls of a flower are the androsium (male part) and gynosium (female part). Therefore, the correct answer to the question is "Androsium and Gynosium".