Why do some cells have more mitochondria than others?

• A. Because they are larger in size.
• B. Because they are involved in photosynthesis.
• C. Because they require more energy for their functions.
• D. Because they have more chloroplasts.

Answer: (C)

Verified step by step guidance

1. Understand the role of mitochondria: Mitochondria are known as the powerhouses of the cell because they generate most of the cell's supply of adenosine triphosphate (ATP), which is used as a source of chemical energy.
2. Consider the energy requirements of different cells: Cells that require more energy for their functions will have more mitochondria. This is because they need to produce more ATP to meet their energy demands.
3. Identify examples of high-energy cells: Muscle cells, especially in the heart and skeletal muscles, are examples of cells with high energy demands and therefore contain a large number of mitochondria.
4. Evaluate the incorrect options: Larger size does not necessarily mean more mitochondria, as energy needs are more related to function than size. Photosynthesis is a process that occurs in chloroplasts, not mitochondria, and cells with more chloroplasts are typically plant cells involved in photosynthesis, not necessarily requiring more mitochondria.
5. Conclude with the correct reasoning: Cells with higher energy requirements, such as muscle cells, have more mitochondria to efficiently produce the ATP needed for their energy-intensive functions.