Choose the correct pair.

Options

A. Coconut, cucurbits - dioecious
B. Honeybee, Rotifers-parthenogensis
C. Ornithorhynchus, Whale - viviparity
D. Frog, Peacock - external fertilisation

Answer

To solve the question "Choose the correct pair," we need to analyze the given options and identify which pair correctly matches the characteristics described.

### Step-by-Step Solution:

1. **Understanding Dioecious and Monoecious Plants**:
- **Dioecious plants** have male and female reproductive organs on separate individuals.
- **Monoecious plants** have both male and female reproductive organs on the same individual.

2. **Analyzing the First Pair (Coconut and Cucurbits)**:
- **Coconut**: This is a monoecious plant as it has both male and female flowers on the same plant.
- **Cucurbits** (like cucumbers and pumpkins): These are also monoecious plants.
- **Conclusion**: This pair is incorrect as both are monoecious.

3. **Analyzing the Second Pair (Honey Bees and Rotifers)**:
- **Honey Bees**: They can reproduce through parthenogenesis, where females can develop from unfertilized eggs.
- **Rotifers**: They also reproduce asexually through parthenogenesis.
- **Conclusion**: This pair is correct as both involve parthenogenesis.

4. **Analyzing the Third Pair (T. ornithorhynchus and Whale)**:
- **T. ornithorhynchus** (Platypus): This is an egg-laying mammal (monotreme).
- **Whale**: Whales are viviparous, meaning they give birth to live young.
- **Conclusion**: This pair is incorrect as they represent different reproductive strategies.

5. **Analyzing the Fourth Pair (Frog and Peacock)**:
- **Frog**: Frogs typically exhibit external fertilization.
- **Peacock**: Peacocks (male peafowl) engage in internal fertilization.
- **Conclusion**: This pair is incorrect as they represent different fertilization methods.

### Final Conclusion:
The only correct pair from the options provided is **Honey Bees and Rotifers**, as both can reproduce through parthenogenesis.

### Answer:
**Option B: Honey Bees and Rotifers (Parthenogenesis)**

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