Which of the following is false about the nervous system of earthworm?
I. Nervous system is basically represented by ganglia arranged on ventral nerve cord.
II. In 3rd and 4th segment, the nerve cord bifurcates and joins the cerebral ganglia dorsally to form a nerve ring
III. In earthworm neurons are sensory, motor and adjustar
IV. The cerebral ganglia alongwith other nerves in the ring integrate sensory input as well as command muscular responses of the body

Options

A. All
B. Only IV
C. Only III
D. None

Answer

To determine which statement about the nervous system of earthworms is false, we will analyze each statement one by one.

### Step 1: Analyze Statement I
**Statement I:** "Nervous system is basically represented by ganglia arranged on ventral nerve cord."
- This statement is **true**. The nervous system of earthworms consists of a ventral nerve cord with a series of ganglia (clusters of nerve cells) that serve as the main components of their nervous system.

### Step 2: Analyze Statement II
**Statement II:** "In 3rd and 4th segment, the nerve cord bifurcates and joins the cerebral ganglia dorsally to form a nerve ring."
- This statement is **true**. The ventral nerve cord does bifurcate in the 3rd and 4th segments, and it connects to the cerebral ganglia, forming a nerve ring that encircles the esophagus.

### Step 3: Analyze Statement III
**Statement III:** "In earthworm neurons are sensory, motor and adjustar."
- This statement is **false**. The term "adjustar" is not commonly used in the context of earthworm anatomy or physiology. The neurons in earthworms are classified as sensory and motor neurons, but "adjustar" does not fit into standard classifications.

### Step 4: Analyze Statement IV
**Statement IV:** "The cerebral ganglia along with other nerves in the ring integrate sensory input as well as command muscular responses of the body."
- This statement is **true**. The cerebral ganglia do play a role in processing sensory information and coordinating muscular responses.

### Conclusion
Based on the analysis, **Statement III** is the false statement regarding the nervous system of earthworms.

### Final Answer
The false statement about the nervous system of earthworm is: **III. In earthworm neurons are sensory, motor and adjustar.**

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