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

What does regular exercise do to bones?

1. Increases flexibility

2. Weakens bone structure

3. Increases bone strength and density

4. Decreases calcium retention

The correct answer is: Increases bone strength and density

Regular exercise plays a crucial role in maintaining and improving the health of bones. When physical activity is performed, particularly weight-bearing and resistance exercises, it stimulates bone formation and enhances the body's ability to retain calcium. This is primarily due to the mechanical stress that exercise places on the bones, encouraging the bone remodeling process in which old bone tissue is replaced with new tissue. As a result, bones become stronger and denser, which helps reduce the risk of fractures and conditions such as osteoporosis later in life. This process is beneficial because it not only bolsters the bone matrix but also increases mineral content within the bones, contributing to overall skeletal health. Additionally, regular exercise encourages better blood flow to bone tissues, further aiding in nutrient delivery and waste removal, which supports the maintenance of healthy bone structures. Thus, the increase in bone strength and density ensures that they can better withstand physical stresses and everyday activities.