Chromosomal basis of sex determination was discovered in the plant :

Options

A. Rumex
B. Melandrium
C. Concinia
D. Spharocarpus

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which plant was the first to show the chromosomal basis of sex determination.

2. **Analyzing the Options**: The options given are:
- A) Rumex
- B) Melandrium
- C) Consinia
- D) Spherocarpus

3. **Identifying Key Information**: The chromosomal basis of sex determination involves the presence of specific sex chromosomes that determine whether an organism is male or female.

4. **Recalling Relevant Knowledge**: It is known that the plant Melandrium was the first to demonstrate the role of the Y-chromosome in sex determination. In this plant, the presence of the Y-chromosome indicates a male, while its absence indicates a female.

5. **Confirming Characteristics of Melandrium**: Melandrium is classified as dioecious, meaning it has distinct male and female individuals, and it possesses heteromorphic sex chromosomes.

6. **Selecting the Correct Answer**: Based on the information gathered, the correct answer to the question is B) Melandrium.

7. **Final Answer**: Therefore, the chromosomal basis of sex determination was discovered in the plant Melandrium.

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