Question

Earthworms have no skeleton but during burrowing, the anterior end becomes turgid and acts as a hydraulic skeleton. It Is due to?

• A. A) Gut peristalsis
• B. B}.Blood
• C. C) Coelomic fluid
• D. D) Setae

Answer 1

The correct option is C

C) Coelomic fluid

The correct option is C

Explaination of the correct answer:

1. Soft-bodied invertebrates have a support structure called a hydraulic skeleton that depends on the incompressibility of bodily fluids.
2. Internal organ support in earthworms is given by the coelomic fluid, which is pressed against the coelom.
3. The hydraulic skeleton causes the anterior end to become turgid during digging, which helps the longitudinal muscles to relax.
4. An alkaline, colorless, or milky coelomic fluid containing water, salts, certain proteins, and four types of coelomic corpuscles—phagocytes, mucocytes, circular nucleated cells, and chloragogen cells—fills the earthworm's bodily cavity (coelom).
5. The coelomic fluid thickens and serves as a hydraulic skeleton while burrowing.

The explanation for the incorrect options:

Option A:

1. Food is moved through the digestive tract by a sequence of wave-like muscle contractions called peristalsis.
2. The process begins in the esophagus, where powerful waves of smooth muscle transport balls of swallowed food to the stomach.

Option B:

1. Blood is a bodily fluid found in humans and other vertebrates with circulatory systems that carry metabolic waste products away from cells while also delivering essential elements like nutrition and oxygen to the cells.
2. The blood is made up of blood cells floating in blood plasma.

Option D:

1. A rigid bristle, hair, or bristle-like process or component on an organism.
2. While many polychaete worms, including earthworms, have setae on their bodies that are utilized for locomotion, spiders employ their setae as sense organs.
3. Geckos' feet include tiny setae that enable them to stick to vertical surfaces

Final Answer: The correct answer is 'Coelomic fluid'.