In bryophytes and algae, lunaric acid replaces

Options

A. Auxin
B. Gibberellin
C. Cytokinin
D. Abscisic acid.

Answer

To answer the question "In bryophytes and algae, lunaric acid replaces," we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Context**: The question refers to lunaric acid and its role in bryophytes and algae. We need to understand what lunaric acid is and how it functions in these plants.

**Hint**: Research the characteristics and functions of lunaric acid in plant biology.

2. **Understand Lunaric Acid**: Lunaric acid is known to act as a growth inhibitor in plants. This means it plays a role in regulating growth, similar to certain plant hormones.

**Hint**: Look into the functions of various plant hormones to see which ones are known to inhibit growth.

3. **Compare with Plant Hormones**: The options given are auxin, gibberellin, cytokinin, and abscisic acid. We need to identify which of these hormones is also known to act as a growth inhibitor.

**Hint**: Recall the roles of the listed hormones: auxin promotes growth, gibberellin promotes stem elongation, cytokinin promotes cell division, and abscisic acid is known for its role as a growth inhibitor.

4. **Identify the Correct Hormone**: Among the options, abscisic acid is recognized as a growth inhibitor in plants. Therefore, it is logical to conclude that lunaric acid, which serves a similar function in bryophytes and algae, replaces abscisic acid.

**Hint**: Think about how different plant hormones interact and their roles in plant growth regulation.

5. **Conclusion**: Based on the analysis, we conclude that in bryophytes and algae, lunaric acid replaces abscisic acid.

**Final Answer**: The correct answer is **abscisic acid**.