Consider the following four statements (a-d) and select the option which includes all the correct ones only?
(a) Genus is a group of related species which has more characters in common in comparison to species of other genera.
(b) Classification is not a single step process.
(c) Solanum, Petunia and Datura are placed in family convolvulaceae
(d) Taxonomic categories are both distinct biological entities and morphological aggregates.

Options

A. Statements a, b
B. Statements a, b, d
C. Statements b, c, d
D. Statements a, b, c

Answer

To solve the question, we need to evaluate each of the four statements (a-d) and determine which ones are correct.

### Step-by-Step Solution:

1. **Evaluate Statement (a)**:
- **Statement**: "Genus is a group of related species which has more characters in common in comparison to species of other genera."
- **Analysis**: This statement is correct. A genus indeed consists of species that share more characteristics with each other than with species from different genera.

2. **Evaluate Statement (b)**:
- **Statement**: "Classification is not a single step process."
- **Analysis**: This statement is also correct. Classification involves multiple steps, including identification, naming, and studying the evolutionary relationships of organisms.

3. **Evaluate Statement (c)**:
- **Statement**: "Solanum, Petunia and Datura are placed in family Convolvulaceae."
- **Analysis**: This statement is incorrect. Solanum, Petunia, and Datura belong to the family Solanaceae, not Convolvulaceae.

4. **Evaluate Statement (d)**:
- **Statement**: "Taxonomic categories are both distinct biological entities and morphological aggregates."
- **Analysis**: This statement is correct. Taxonomic categories can be based on distinct biological entities (individual organisms) and also on morphological characteristics (morphological aggregates).

### Conclusion:
- The correct statements are (a), (b), and (d).
- Therefore, the option that includes all the correct statements is option 2.

### Final Answer:
**Option 2: (a), (b), and (d) are correct.**

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