Chapter 2
Human Body: The Skeletal System
IV. Challenge
1. If we had no joints, we would not be able to move or bend our body. Our body would become stiff.
Elderly people get joint pain because their bones become weak and their joints wear out with age.
2. If our muscles become weak, we will not be able to move properly and we will feel tired very easily.
3. We feel muscle pain after heavy exercise because a substance called lactic acid is formed in our muscles.
4. If our spine gets injured, it can cause loss of muscle function and sensation in different parts of the body.
5. Children should eat more proteins because they are growing and proteins help in body growth and repair.
6. The cast keeps the broken bones in the correct position and does not allow them to move. This helps the bones to join and heal properly.
IV. Challenge
1. Overweight means having more body weight than normal, while obesity means having too much body fat and being very overweight.
2. Junk food is full of fat and sugar with very less nutritional value. It generally consists of ingredients which lack iron. So, this may lead to cause anaemia.
3. Cakes, bakery products and sugary drinks are not healthy because these are junk foods with very low nutritional value. They are full of fat and sugar which are harmful for health.
4. People suffering from anaemia always feel tired because of low production of red blood cells and blood loss.
5. Goitre can be prevented by eating sea food because it naturally contains salt.
6. Carbohydrates are the foods which give us energy to do work, so it is not advisable to completely eliminate healthy high-carb items from our diet. But, it is also advisable to have these in limit.
