Presence of gills in the tadpole of frog indicates that `:`

Options

A. frog will have gills in future
B. frog evolved from gilled ancestors
C. fishes were amphibians in the past
D. fish evolved from frog-like ancestors

Answer

To solve the question regarding the presence of gills in the tadpole of a frog, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Organism**: Recognize that a tadpole is the larval stage of a frog. During this stage, the tadpole is aquatic and relies on gills for respiration.

2. **Understand the Function of Gills**: Gills are specialized organs that allow aquatic animals, like fish and tadpoles, to extract oxygen from water. This indicates that the tadpole is adapted to an aquatic environment.

3. **Consider Evolutionary Relationships**: The presence of gills in the tadpole suggests an evolutionary link to ancestors that also possessed gills. Frogs, as amphibians, are believed to have evolved from fish-like ancestors.

4. **Evaluate the Options**:
- **Option 1**: "Frog will have gills in future" - This is incorrect as adult frogs do not have gills.
- **Option 2**: "Frog evolved from gilled ancestor" - This is correct as it aligns with the evolutionary history of amphibians.
- **Option 3**: "Fishes were amphibians in the past" - This is misleading; fish and amphibians are distinct groups.
- **Option 4**: "Fish evolved from frog-like ancestors" - This is incorrect; it is the other way around.

5. **Conclusion**: Based on the analysis, the correct answer is that the presence of gills in the tadpole indicates that the frog evolved from a gilled ancestor.

### Final Answer:
The presence of gills in the tadpole of a frog indicates that **the frog evolved from a gilled ancestor**.

---