Largest number of species are traced in

Options

A. Arthropoda
B. Echinodermata
C. Bacteria
D. Fungi

Answer

To answer the question "Largest number of species are traced in," we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Options**: The options provided are:
- Orthopoda
- Echinoderm
- Bacteria
- Fungi

2. **Understand the Phyla**:
- **Orthopoda**: This is a phylum that includes insects, arachnids, and crustaceans. It is known for having a vast number of species.
- **Echinoderm**: This phylum includes marine animals like starfish and sea urchins. It has fewer species compared to Orthopoda.
- **Bacteria**: While bacteria are incredibly diverse and numerous, they are not classified in the same way as the other options.
- **Fungi**: This kingdom includes mushrooms and molds, but it has fewer species than Orthopoda.

3. **Research Species Count**:
- It is estimated that Orthopoda has over 1 million described species, with insects making up more than 90% of this number. This makes it the largest phylum in terms of species diversity.

4. **Conclusion**: Based on the information gathered, the phylum with the largest number of species is Orthopoda.

5. **Final Answer**: The correct answer is **Orthopoda**.