A group of very closely related species that share a number of similar traits is called a(an)

Options

A. phylum
B. order
C. genus
D. class

Answer

To answer the question, "A group of very closely related species that share a number of similar traits is called a(an)", we need to analyze the options provided: phylum, order, genus, and class.

### Step-by-Step Solution:

1. **Understanding Biological Classification**:
- Biological classification is a hierarchical system used to categorize living organisms based on shared characteristics.

2. **Identifying the Options**:
- **Phylum**: This is a higher taxonomic rank that groups together organisms that share a basic structural framework. It includes multiple classes.
- **Class**: This is a rank below phylum and includes multiple orders. It groups organisms that share more specific characteristics.
- **Order**: This is a rank below class and includes multiple families. It groups organisms that are even more closely related.
- **Genus**: This is a rank below family and includes closely related species that share very similar traits.

3. **Determining the Closest Group**:
- The question specifies "very closely related species". Among the options, the term that refers specifically to a group of closely related species is "genus".

4. **Conclusion**:
- Therefore, the correct answer to the question is "genus".

### Final Answer:
A group of very closely related species that share a number of similar traits is called a **genus**.

---