Which of the following is monoecious

Options

A. Date palm
B. Marachantia
C. Cycas
D. Pinus

Answer

To determine which of the given options is monoecious, we will analyze each option based on the definitions and characteristics of monoecious and dioecious plants.

### Step-by-Step Solution:

1. **Understanding Monoecious Plants**:
- The term "monoecious" comes from the Greek words "mono" meaning "one" and "oikos" meaning "house." Monoecious plants have both male and female reproductive structures on the same individual. This means that a single plant can produce both male and female flowers or cones.

2. **Analyzing the Options**:
- **Option A: Date Palm**
- Date palms have male and female flowers that develop on separate individuals. Therefore, they are dioecious, not monoecious.

- **Option B: Marcantia (Marchantia polymorpha)**
- Marcantia is a liverwort that also has male and female organs on different thalli (plant structures). Hence, it is dioecious.

- **Option C: Cycus**
- Cycus is a gymnosperm where male and female cones (strobili) are produced on separate trees. Thus, Cycus is also dioecious.

- **Option D: Pinus**
- Pinus, like Cycus, is a gymnosperm. However, in Pinus, both male and female cones are present on the same plant, although they are borne on separate strobili. This characteristic makes Pinus monoecious.

3. **Conclusion**:
- After analyzing all the options, we find that the only monoecious plant among the given options is **Pinus**.

### Final Answer:
**Pinus is the monoecious plant among the options provided.**

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