The ascending or descending arrangement of taxonomic categories is called as

Options

A. classification
B. taxonomy
C. hierarchy
D. key.

Explanation

To answer the question "The ascending or descending arrangement of taxonomic categories is called as," we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Taxonomic Categories**:
- The main taxonomic categories are: Kingdom, Phylum, Class, Order, Family, Genus, and Species.

2. **Understand the Arrangement**:
- These categories can be arranged in two ways: ascending (from species to kingdom) and descending (from kingdom to species).

3. **Define the Term**:
- The arrangement of these categories is referred to as a "hierarchy." This means that each level of classification is ranked and can be understood in relation to the levels above and below it.

4. **Choose the Correct Option**:
- From the options provided: classification, taxonomy, hierarchy, and key, the term that specifically refers to the ascending or descending arrangement of taxonomic categories is "hierarchy."

5. **Conclusion**:
- Therefore, the correct answer to the question is "hierarchy."

### Final Answer:
The ascending or descending arrangement of taxonomic categories is called as **hierarchy**.

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