Mark the false statement w.r.t. frog

Options

A. A mature female frog can lay 2500 to 3000 ova at a time
B. Fertilisation is external and takes place on land
C. Thyroxine hormone is required for metamorphosis of tadpole to form the adult
D. Tadpole larva has a long coiled spring like instestine.

Explanation

To determine the false statement with respect to frogs, let's analyze each option step by step.

### Step-by-Step Solution:

1. **Option A: A mature female frog can lay 2500-3000 ova at a time.**
- This statement is true. Female frogs are known to lay a large number of eggs (ova) to increase the chances of survival against predators. Therefore, this is not the false statement.

2. **Option B: Fertilization is external and takes place on the land.**
- This statement is partially true and partially false. While it is correct that fertilization in frogs is external, it does not take place on land; it occurs in water. Thus, this statement is false because it incorrectly states the location of fertilization.

3. **Option C: Thyroxine hormone is required for metamorphosis of tadpole to form the adult.**
- This statement is true. The hormone thyroxine, produced by the thyroid gland, is essential for the metamorphosis process from tadpole to adult frog. Without this hormone, tadpoles cannot undergo metamorphosis.

4. **Option D: Tadpole larva has a long coiled spring-like intestine.**
- This statement is also true. Tadpoles have a long, coiled intestine which aids in digestion, similar to that of some reptiles.

### Conclusion:
The false statement is **Option B**: "Fertilization is external and takes place on the land."