What helps in flowering

Options

A. Cytochrome
B. ABA
C. Phytochrome
D. Ethylene

Answer

To determine what helps in flowering, we need to analyze the options provided and understand the role of each substance in the flowering process.

### Step-by-Step Solution:

1. **Understanding Cytochrome**:
- Cytochromes are proteins involved in energy synthesis, particularly in the formation of ATP (adenosine triphosphate). They play a crucial role in cellular respiration but do not directly induce flowering.
- **Conclusion**: Cytochrome does not help in flowering.

2. **Analyzing Abscisic Acid (ABA)**:
- ABA is known as a stress hormone. It inhibits plant growth, promotes abscission (the shedding of leaves), and prevents seed germination under stress conditions.
- **Conclusion**: ABA is an inhibitory hormone and does not promote flowering.

3. **Examining Phytochrome**:
- Phytochromes are pigment proteins that are crucial for the flowering process. They are sensitive to light and exist in two forms: PR (red light-absorbing form) and PFR (far-red light-absorbing form).
- When PR absorbs red light (around 660 nm), it converts to PFR. PFR can then absorb far-red light (around 730 nm) and can convert back to PR.
- Phytochromes are essential for both short-day plants (SDP) and long-day plants (LDP) to induce flowering. In SDPs, the active form is PR, while in LDPs, it is PFR.
- **Conclusion**: Phytochrome is a key factor that helps in flowering.

4. **Considering Ethylene**:
- Ethylene is a plant growth regulator primarily involved in the ripening of fruits. While it plays a role in various plant processes, it does not directly induce flowering.
- **Conclusion**: Ethylene does not help in flowering.

### Final Answer:
The substance that helps in flowering is **Phytochrome**.

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