Choose the correct pair

Options

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

Answer

To solve the question "Choose the correct pair," we need to evaluate each of the given options and determine which pair is correct based on the reproductive methods of the organisms mentioned.

### Step-by-Step Solution:

1. **Evaluate Option 1: Coconut and Cucurbit with Dioecious**
- **Definition**: Dioecious plants have male and female reproductive organs on separate individuals.
- **Analysis**: Both coconut and cucurbit (like cucumbers) are monoecious plants, meaning they have both male and female flowers on the same plant.
- **Conclusion**: This pair is incorrect.

2. **Evaluate Option 2: Honey Bee and Rotifers with Parthenogenesis**
- **Definition**: Parthenogenesis is a form of asexual reproduction where an unfertilized egg develops into a new individual.
- **Analysis**: Honey bees can reproduce through parthenogenesis, where unfertilized eggs develop into males (drones). Rotifers also reproduce through this method.
- **Conclusion**: This pair is correct.

3. **Evaluate Option 3: Ornithorhynchus (Platypus) and Whale with Viviparity**
- **Definition**: Viviparity is a reproductive method where the young develop inside the mother and are born live.
- **Analysis**: While whales are viviparous, the platypus (Ornithorhynchus) is an exception among mammals as it lays eggs.
- **Conclusion**: This pair is incorrect.

4. **Evaluate Option 4: Frog and Peacock with External Fertilization**
- **Definition**: External fertilization occurs when the male and female gametes unite outside the female's body.
- **Analysis**: Frogs typically exhibit external fertilization, while peacocks (birds) do not; they have internal fertilization.
- **Conclusion**: This pair is incorrect.

### Final Answer:
The only correct pair is **Option 2: Honey Bee and Rotifers with Parthenogenesis**.