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

How does the structure of a sperm cell aid in its primary function?

1. It has a large nucleus for genetic material

2. It has a long tail for swimming

3. It has a rigid cell wall for protection

4. It has flagella for movement in plants

The correct answer is: It has a long tail for swimming

The structure of a sperm cell is specifically adapted to its primary function of fertilization, and the presence of a long tail, or flagellum, is crucial in this regard. This long tail provides the necessary propulsion that enables the sperm to swim effectively through the female reproductive tract to reach the ovum. The movement facilitated by the tail allows the sperm to navigate and overcome obstacles in a fluid environment, which is essential for successful fertilization. The other options relate to structures or features that do not accurately align with the function of a sperm cell. While a large nucleus is important for genetic material in many types of cells, sperm cells actually possess a simplified structure to maximize mobility, and they have a streamlined shape rather than a large nucleus. A rigid cell wall is characteristic of plant cells, not animal cells like sperm, which require flexibility to swim. Lastly, flagella are indeed involved in movement, but in the context of plants, they do not pertain to sperm cells. Thus, the design of the sperm cell with a long tail optimally supports its role in reproduction.