Which has no skeleton ?

Options

A. Cockroach
B. Mosquito
C. Butterfly
D. Jelly fish

Answer

To determine which organism has no skeleton, we need to analyze the options provided: cockroach, mosquito, butterfly, and jellyfish.

### Step-by-Step Solution:

1. **Identify the Organisms**:
- The options given are cockroach, mosquito, butterfly, and jellyfish.

2. **Classify the Organisms**:
- Cockroach, mosquito, and butterfly are all insects and belong to the phylum Arthropoda.
- Jellyfish belongs to the phylum Cnidaria (previously known as Coelenterata).

3. **Understand Skeleton Types**:
- Insects (cockroach, mosquito, butterfly) have an exoskeleton, which is a hard outer covering that provides support and protection.
- Jellyfish do not have a true skeleton. Instead, they have a gelatinous substance called mesoglea, which is not considered a skeleton.

4. **Analyze the Skeleton Presence**:
- Cockroach, mosquito, and butterfly possess exoskeletons.
- Jellyfish lacks a skeleton in the traditional sense and is primarily composed of soft tissue.

5. **Conclusion**:
- Since jellyfish does not have a skeleton, the correct answer is **jellyfish**.

### Final Answer:
The organism that has no skeleton is **jellyfish**.

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