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

How are nerve cells specialised to function in the nervous system?

1. They produce hormones to transmit signals

2. They are very long and carry electrical impulses

3. They can regenerate after damage

4. They have multiple nuclei for efficiency

The correct answer is: They are very long and carry electrical impulses

Nerve cells, or neurons, are specialized for their role in the nervous system primarily due to their elongated structure. This length allows them to efficiently transmit electrical impulses over long distances, connecting different parts of the body to the brain and spinal cord. The processes of neurons, including axons, can extend even meters in length, enabling rapid communication between neurons and facilitating the coordination of bodily functions and responses to stimuli. This unique structure also supports the rapid conduction of electrical signals, as it allows for the myelination of axons, which enhances the speed of signal transmission through a process called saltatory conduction. This is crucial for the quick reflexes and responses that the nervous system must manage. Other characteristics of neurons, such as synaptic terminals, further enable neurotransmitter release to communicate signals between adjacent nerve cells. While some other options mention features that could be found in other types of cells or tissues, they do not accurately describe the core function of neurons in the context of nerve signal transmission as effectively as the length and structure of the cells.