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

How do root hair cells utilize active transport to absorb minerals?

1. By reducing energy demands

2. By using a high concentration of nitrates

3. By containing many mitochondria for energy

4. By expanding their size rapidly

The correct answer is: By containing many mitochondria for energy

Root hair cells play a crucial role in the absorption of minerals from the soil, and active transport is a key mechanism they utilize. Active transport is the process by which cells move substances against their concentration gradient, requiring energy, typically in the form of ATP. The correct choice highlights that root hair cells contain many mitochondria, which are the powerhouses of the cell responsible for producing ATP. This high number of mitochondria ensures that the cells have sufficient energy to perform active transport efficiently. When root hair cells absorb minerals such as nitrates, they do so against the concentration gradient, which means they must expend energy. The abundance of mitochondria supports this energy demand, facilitating the uptake of essential nutrients needed for plant growth and development. Understanding the roles various organelles play in cellular functions is critical in biology. The presence of many mitochondria indicates a cell is heavily involved in processes that require significant energy, such as the active transport of minerals in the case of root hair cells.