OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

What is the effect of an electrical impulse traveling along a sensory neuron?

1. It stops communication

2. It decreases response time to stimuli

3. It conveys information to the central nervous system

4. It generates hormones for response

The correct answer is: It conveys information to the central nervous system

An electrical impulse traveling along a sensory neuron plays a critical role in the communication of information to the central nervous system. When a sensory neuron is stimulated by a specific stimulus, such as light, sound, or touch, it generates an electrical signal. This signal is then transmitted rapidly along the neuron, ultimately reaching the central nervous system (CNS), which is composed of the brain and spinal cord. The primary function of sensory neurons is to relay information about external and internal stimuli to the CNS, where it can be processed and interpreted. This process is essential for enabling the body to react appropriately to different stimuli, as the CNS can coordinate responses based on the information received from sensory neurons. The other options do not accurately represent the main effect of an electrical impulse along a sensory neuron. While it's true that impulses can contribute to quicker responses to stimuli, the fundamental role of conveying information is the most direct and crucial function of sensory neurons. Hormone generation is a function carried out by endocrine glands rather than sensory neurons, and stopping communication does not align with the purpose of sensory impulses, which is to send signals.