Explanation:
Ascaris is a parasitic roundworm that infects the small intestines of humans and animals. It has a simple nervous system consisting of a ventral nerve cord and a ventral ganglion.

What is a ganglion?
A ganglion is a cluster of nerve cell bodies outside the central nervous system. Ganglia are found along the ventral nerve cord of Ascaris.

Ganglionated nerve in Ascaris:
The nerve that is ganglionated in Ascaris is the ventral nerve. This nerve is located on the ventral side of the roundworm's body. It runs along the length of the worm's body and is responsible for transmitting signals between different parts of the nervous system.

Functions of the ventral nerve:
The ventral nerve in Ascaris has several important functions, including:
1. Sensory input: It receives sensory information from the environment, such as temperature, touch, and chemical stimuli.
2. Motor output: It controls the movement of muscles in the worm's body, allowing it to crawl and navigate its environment.
3. Coordination: The ventral nerve integrates sensory information and coordinates motor output, allowing the worm to respond appropriately to its surroundings.

Importance of ganglionation:
Ganglionation in the ventral nerve allows for more complex nervous system function in Ascaris. Ganglia are clusters of nerve cell bodies that contain many neurons. These neurons can process sensory information and generate appropriate motor responses. Ganglionation also allows for the integration of information from different parts of the body, enabling coordinated movement and behavior.

In conclusion, the ventral nerve in Ascaris is ganglionated, meaning it contains ganglia along its length. This ganglionation allows for the integration of sensory information and the generation of motor responses, enabling the worm to interact with its environment.