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

What is primarily conveyed by the electrical impulses that travel through neurons?

1. Voluntary muscle actions only

2. Information from the sensory receptors

3. The emotional state of the individual

4. Messages to and from the endocrine system

The correct answer is: Information from the sensory receptors

The choice indicating that information from the sensory receptors is conveyed by electrical impulses traveling through neurons is correct because neurons transmit signals that originate from sensory receptors throughout the body. These sensory receptors detect stimuli such as light, sound, touch, temperature, and chemical signals. This sensory information is converted into electrical impulses that travel along sensory neurons to the central nervous system, where it can be processed and interpreted. Neurons play a crucial role in the nervous system by enabling the communication of these messages. When a sensory receptor is stimulated, it generates an electrical signal that travels along the neuron to the brain or spinal cord, allowing for perception and response to the external environment. In contrast, the other options do not accurately reflect the primary function of neuron impulses. While voluntary muscle actions can involve neuronal activity, they are not the sole message transmitted by neurons, as they also convey sensory information and reflex actions. Emotional states may influence neuron activity, but they are not directly communicated through electrical impulses in the same way sensory information is. Similarly, while some neurons interact with the endocrine system, the primary role of electrical impulses is not to serve as messages to and from that system.