Choose the odd one w.r.t. cryptogams

Options

A. Chlamydomonas
B. Porphyra
C. Anabaena
D. Spirogyra

Answer

To solve the question "Choose the odd one with respect to cryptogams," we will follow these steps:

### Step 1: Understand the Definition of Cryptogams
Cryptogams are a group of plants that reproduce via spores rather than seeds. Their reproductive structures are hidden, which distinguishes them from seed-producing plants (fenerogams).

### Step 2: Identify the Categories of Cryptogams
Cryptogams are further divided into three main categories:
- **Thalophyta**: Includes algae (e.g., green algae, red algae).
- **Bryophyta**: Includes mosses and liverworts.
- **Pteridophyta**: Includes ferns.

### Step 3: Analyze the Given Options
The options provided are:
1. Chlamydomonas (green algae)
2. Porphyra (red algae)
3. Anabaena (cyanobacteria)
4. Spirogyra (green algae)

### Step 4: Classify Each Option
- **Chlamydomonas**: This is a green algae and falls under Thalophyta, thus it is a cryptogam.
- **Porphyra**: This is a red algae and also falls under Thalophyta, thus it is a cryptogam.
- **Anabaena**: This is a cyanobacterium (blue-green algae) and does not fall under cryptogams; it belongs to the kingdom Monera, which is prokaryotic.
- **Spirogyra**: This is a green algae and falls under Thalophyta, thus it is a cryptogam.

### Step 5: Identify the Odd One Out
From the analysis, we see that:
- Chlamydomonas, Porphyra, and Spirogyra are all classified as cryptogams.
- Anabaena is the only one that does not belong to the cryptogams category.

### Conclusion
The odd one with respect to cryptogams is **Anabaena** (Option C).

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