How many of the following are examples of homologus structures in plant :
(a) Eyes of octapus and mammal
(b) Potato and sweet potato
(c) Forelimbs of whale, bat cheetah and human
(d) Vertebrate heart
(e) Thorn of bougainvillea and tendril of cucurbita
(f) Potato and corrot
(g) Potato and radish

Options

A. Four
B. Three
C. Two
D. One

Answer

To determine how many of the given structures are examples of homologous structures in plants, we need to analyze each option based on the definition of homologous structures. Homologous structures are those that have a similar origin but may serve different functions. Let's evaluate each option:

1. **Eyes of octopus and mammal**:
- These structures have different origins (octopus is a mollusk and mammals are vertebrates) but serve a similar function (vision). Therefore, they are analogous, not homologous.
- **Conclusion**: Not homologous.

2. **Potato and sweet potato**:
- The potato is a stem modification (tuber), while the sweet potato is a root modification. They have different origins.
- **Conclusion**: Not homologous.

3. **Forelimbs of whale, bat, cheetah, and human**:
- These forelimbs have the same origin (they are derived from the same ancestral limb) but serve different functions (swimming, flying, running, and manipulation). However, since they are not plant structures, they do not count for this question.
- **Conclusion**: Not homologous in plants.

4. **Vertebrate heart**:
- The vertebrate heart is a structure found in animals, not plants. Even though it may be homologous among vertebrates, it does not apply to plant structures.
- **Conclusion**: Not homologous in plants.

5. **Thorn of Bougainvillea and tendril of Cucurbita**:
- Both structures arise from the same origin (stem) but serve different functions (defense for thorns and climbing for tendrils). Therefore, they are homologous structures.
- **Conclusion**: Homologous.

6. **Potato and carrot**:
- The potato is a stem modification, while the carrot is a root modification. They have different origins.
- **Conclusion**: Not homologous.

7. **Potato and radish**:
- Similar to the previous case, the potato is a stem modification, and the radish is a root modification. They have different origins.
- **Conclusion**: Not homologous.

After evaluating all the options, we find that only the thorn of Bougainvillea and the tendril of Cucurbita are homologous structures in plants.

**Final Answer**: 1 example of homologous structures in plants.