Question

If a live earthworm is pricked with needle on its outer surface without damaging its gut, the fluid that comes out is

• A. Excretory fluid.
• B. Slimy mucus.
• C. Hemolymph.
• D. Coelomic fluid.

Answer 1

The correct option is D

Coelomic fluid.

The correct option is D.

Explanation of the correct option:

1. The coelomic fluid, which is made up of a watery matrix, plasma, and numerous coelomocytes with a variety of roles, is crucial for the development of innate immunity.
2. Earthworms typically exude coelomic fluid to keep their bodies moist and support their physiological functions.
3. Without hurting its gut, the earthworm's outer surface is pierced by a needle, and coelomic fluid leaks out.

Explanation of the incorrect options:

Option A:

1. In earthworms, excretion happens through a pore known as the nephridiopore.
2. They require a system for tubular reabsorption by a capillary network before excretion since they are more developed than flame cells.

Option B:

1. Oxygen won't pass through the skin directly; it must first combine with moist slime before doing so.
2. So, to prevent suffocation, earthworms need to have moist skin.
3. Blood capillaries exist beneath the skin's surface and are where the slime and air mixture enters the body.

Option C:

1. The closed circulatory system is a system in which blood is always contained within vessels of various sizes.
2. In most invertebrates, hemolymph is a fluid that fills the hemocoel and is equivalent to blood.

Final answer: If a live Earthworm is pricked with a needle on its outer surface without damaging its gut, the fluid that comes out is coelomic fluid.