Why are some patients of diabetes treated by giving injections of insulin?

Which of the following is a plant hormone?

1. Insulin
2. Thyroxin
3. Oestrogen
4. Cytokinin

The brain is responsible for

1. thinking
2. regulating the heart beat
3. balancing the body
4. all of the above

What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?