Which taxonomy is based on following points-
* chromosome number
* chromosome structure
* chromosome behaviour

Answer

**Step-by-Step Solution:**

1. **Understanding Taxonomy**: Taxonomy is the science of classification of living organisms. It involves categorizing organisms based on various characteristics.

2. **Identifying Key Points**: The question specifies three key points: chromosome number, chromosome structure, and chromosome behavior.

3. **Defining Cytotaxonomy**: The taxonomy that focuses on these specific points is known as **cytotaxonomy**. This branch of taxonomy uses cytological (cellular) characteristics to classify and differentiate species.

4. **Chromosome Number**: In cytotaxonomy, the chromosome number is a fundamental characteristic. It is constant across all individuals of a species and can be used to distinguish one species from another.

5. **Chromosome Structure**: The structure of chromosomes, including their morphology and the shape of the metaphase chromosomes, is also crucial in classification. The position of the centromere is an important aspect of chromosome structure that is considered.

6. **Chromosome Behavior**: This aspect refers to how chromosomes behave during processes like meiosis. It can provide insights into fertility and sterility among populations, which can be critical for understanding genetic relationships.

7. **Conclusion**: Based on the above points, the correct answer to the question is **cytotaxonomy**.

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