What characters are associated with bean plant I. Cup-shaped thalamus. II. papilionaceous corolla. III. Actinomorphic flowers. IV. Axile placentation.

Options

A. II and IV
B. III and IV
C. I and II
D. I and III

Answer

To determine the characters associated with the bean plant, we will evaluate each of the given statements one by one:

1. **Cup-shaped thalamus**:
- The bean plant, which belongs to the family Leguminosae (or Fabaceae), indeed exhibits a cup-shaped thalamus. This structure serves as a receptacle for the flower parts.
- **Conclusion**: This statement is **correct**.

2. **Papilionaceous corolla**:
- The term "papilionaceous" refers to a butterfly-like flower structure that is characteristic of the Leguminosae family. In this structure, there is one large standard petal (the "vexillum"), two wing petals, and two fused petals forming a keel.
- **Conclusion**: This statement is **correct**.

3. **Actinomorphic flowers**:
- Actinomorphic flowers are radially symmetrical, meaning they can be divided into equal halves by multiple planes. However, the flowers of the bean plant are bilaterally symmetrical, which means they can only be divided into two equal halves by one plane.
- **Conclusion**: This statement is **incorrect**.

4. **Axile placentation**:
- Axile placentation refers to a type of placentation where the ovules are attached to the central axis of a multilocular ovary. In the case of the bean plant, the ovary is typically unilocular with marginal placentation.
- **Conclusion**: This statement is **incorrect**.

**Final Summary**: The correct characters associated with the bean plant are:
- I. Cup-shaped thalamus (Correct)
- II. Papilionaceous corolla (Correct)
- III. Actinomorphic flowers (Incorrect)
- IV. Axile placentation (Incorrect)

Thus, the correct answers are statements I and II.