How many obligate categories or ranks are found in a hierarchical level of classification ?

Explanation

To answer the question about how many obligate categories or ranks are found in a hierarchical level of classification, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Taxonomic Hierarchy**: The taxonomic hierarchy is a system used to classify and organize living organisms into different ranks or categories.

2. **Identifying Obligate Ranks**: In biological classification, there are specific ranks that are considered obligate, meaning they are essential and universally recognized in the classification system.

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