**Statement 1: Annelids possess longitudinal and circular muscles which help in locomotion**

Annelids, which include earthworms and leeches, possess both longitudinal and circular muscles in their body walls. These muscles are responsible for the locomotion of annelids.

**Longitudinal Muscles**:
- Longitudinal muscles run parallel to the length of the annelid's body.
- These muscles contract and relax in a coordinated manner, causing the body to elongate and shorten.
- When the longitudinal muscles contract, the body becomes shorter and thicker, allowing the annelid to move forward.
- When the longitudinal muscles relax, the body becomes longer and thinner, enabling the annelid to stretch and anchor itself.

**Circular Muscles**:
- Circular muscles are arranged in rings around the body of the annelid.
- These muscles also contract and relax in a coordinated manner.
- When the circular muscles contract, the diameter of the body decreases, causing the annelid to become thinner and elongated.
- When the circular muscles relax, the diameter of the body increases, allowing the annelid to anchor itself or expand its body during locomotion.

The coordinated contraction and relaxation of the longitudinal and circular muscles in annelids allow them to move in a peristaltic motion. This motion involves the alternate contraction and relaxation of different segments of the body, propelling the annelid forward.

**Statement 2: Nereis possess dorsal appendages called parapodia which help in swimming**

Nereis, a type of polychaete worm, possesses dorsal appendages called parapodia. Parapodia play a crucial role in the locomotion of nereis, including swimming.

**Parapodia**:
- Parapodia are paired, paddle-like appendages found on each segment of the nereis worm.
- They are located on the dorsal side of the body and extend outward.
- Parapodia are covered in numerous bristles called chaetae, which provide traction and aid in movement.
- By manipulating their parapodia, nereis worms can generate swimming movements.
- The parapodia act as paddles, propelling the worm through the water by undulating or flapping the appendages.

Nereis primarily uses its parapodia for swimming, but they also assist in burrowing and crawling through substrates. The parapodia's flexibility and controlled movements allow the worm to navigate its environment efficiently.

**Conclusion:**
Both Statement 1 and Statement 2 are correct. Annelids possess longitudinal and circular muscles for locomotion, and nereis possesses dorsal appendages called parapodia, which aid in swimming.

Ans. is b becz as annelids r colemates they possess both lateral nd longitudinal muscles that help in locomotion nd Neries posses lateral not dorsal appendages for swimming which are highly vascularised that help even in respiration.