Which of the following is dioecious ?

Options

A. Maize
B. Cycas
C. Pinus
D. Both (a) and (b)

Answer

To determine which of the given options is dioecious, we need to understand the definition of dioecious plants. Dioecious plants are those that have separate male and female individuals, meaning that one plant will produce only male gametes (pollen), while another plant will produce only female gametes (ovules).

### Step-by-Step Solution:

1. **Understand Dioecious Plants**: Dioecious plants have distinct male and female plants. This means that for reproduction, both a male and a female plant are required.

2. **Analyze the Options**:
- **A. Maize**: Maize (Zea mays) is a monoecious plant, meaning it has both male (tassels) and female (ears) reproductive structures on the same plant.
- **B. Cyclus**: Cyclus (likely referring to Cycas) is a dioecious plant. It has separate male and female plants, each producing different types of cones (male cones produce pollen, and female cones produce ovules).
- **C. Pionist**: This term seems to be a typographical error or misinterpretation. If it refers to a specific plant, it is not commonly recognized in the context of dioecious plants.
- **D. Both A and B**: Since A (Maize) is monoecious and B (Cyclus) is dioecious, this option is incorrect.

3. **Conclusion**: The only dioecious plant among the options provided is **Cyclus** (or Cycas).

### Final Answer:
The correct answer is **B. Cyclus**.

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