Urea is excreted by :

Question

Accepted Answer

Urea is excreted by:

Option 1: Frog (Adult)

Explanation:

1. **Why Option 1 is Correct:**
   - Adult frogs are amphibians that primarily excrete urea as their main nitrogenous waste product. This process is known as ureotelism. Frogs, like many other amphibians, have adapted to excrete urea because it is less toxic than ammonia and can be stored in the body for longer periods without causing harm. This adaptation is particularly useful for adult frogs, which often live in environments where water conservation is important. By excreting urea, frogs can maintain water balance and survive in both aquatic and terrestrial habitats.

2. **Why the Other Options are Incorrect:**

- **Option 2: Star Fish**
     - Starfish are echinoderms and primarily excrete ammonia as their nitrogenous waste. Ammonia is highly soluble in water and is easily excreted by aquatic animals like starfish, which live in marine environments where water is abundant. Therefore, starfish do not excrete urea.

- **Option 3: Land Snails**
     - Land snails are terrestrial mollusks that typically excrete uric acid as their primary nitrogenous waste. Uric acid is less toxic and conserves water, which is advantageous for land snails living in environments where water is limited. Thus, land snails do not excrete urea.

- **Option 4: Hydra**
     - Hydra are simple, freshwater cnidarians that primarily excrete ammonia. Due to their aquatic habitat, ammonia can be easily diffused into the surrounding water. Hydra do not have the complex excretory systems required to produce urea, so they do not excrete urea.

In conclusion, the correct answer is Option 1: Frog (Adult), as adult frogs excrete urea, which is suitable for their amphibious lifestyle and helps them manage water conservation effectively.