Activity 3.4 Let us investigate, Let us investigate What percentage of total body weight. Class 9

Activity 3.4 Let us investigate, Let us investigate What percentage of total body weight. Class 9

Activity 3.4 Let us investigate

Aim: Let us investigate What percentage of total body weight comes from bones and muscles?

Observation:

1. Each student's estimated bone mass is approximately 12-15% of their total body weight. Estimated muscle mass is approximately 40-50% in males and 30-40% in females.
2. Total bone + muscle mass accounts for roughly 50-65% of the total body weight in most students.
3. Comparison with classmates shows variation in hone and muscle mass percentages based on age, gender, physical activity levels and body composition.
4. The class average helps identify the typical range for the group and highlights individual differences.

Explanation: Bones and muscles together form a major part of total body weight. Bones are composed of a rigid matrix containing calcium and phosphorus, while muscles are made up of bundles of long, cylindrical cells called muscle fibres. The musculoskeletal system — consisting of bones, muscles, joints, cartilage, tendons and ligaments — helps the body stand upright, move, maintain posture and protect delicate organs. The adult human skeleton makes up about 12—15 per cent of body weight, though this can vary with age, gender and body composition.

Conclusion: This activity helps students understand the significant contribution of bones and muscles to total body weight and heights the importance of maintanance a healthy musculoskeletal system through proper nutrition and exercise.