Chemicals that carry messages across the synapse to the dendrite of a receiver neuron are called _____.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Neurotransmitters
Option (1) Axons — Incorrect. An axon is the long fibre of a neuron that carries the electrical impulse away from the cell body towards the nerve ending. It is a part of the neuron, not a chemical.
Option (2) Cell body — Incorrect. The cell body is the main part of the neuron that contains the nucleus and keeps the cell alive. It is not a chemical that crosses the synapse.
Option (3) Neurotransmitters — Correct. A tiny space called the synapse separates one neuron from the next, and the message must move across that space. When an electrical impulse reaches a neuron’s ending, the nerve ending is stimulated to release a chemical, called a neurotransmitter, which carries the message across.
Option (4) Dendrite — Incorrect. Dendrites are the branch-like fibres of a neuron that receive messages from other neurons. The question itself names the dendrite as the place the message reaches, so it cannot be what carries the message.
NCERT (2025-26): “Factors Underlying Abnormal Behaviour … Biological researchers have found that psychological disorders are often related to problems in the transmission of messages from one neuron to another. You have studied in Class XI, that a tiny space called synapse separates one neuron from the next, and the message must move across that space. When an electrical impulse reaches a neuron’s ending, the nerve ending is stimulated to release a chemical, called a neuro-transmitter. Studies indicate that abnormal activity by certain neuro-transmitters can lead to specific psychological disorders.…” |