Important questions based on NCERT syllabus for Chapter 7 - Control and Coordination:
Question-1: Why are some patients of diabetes treated by giving injections of insulin?
Solution: 1. Insulin is a hormone secreted by the pancreas that regulates the sugar level in the blood.
2. When this hormone is not synthesized in proper amount then the sugar level in the blood rises, then the person is said to be suffering from diabetes. This is the reason why diabetic patients are treated by giving injections of insulin.
Question-2: Why is the use of iodized salt advisable?
Solution: 1. Iodine is needed by the thyroid gland for the production thyroxin hormone.
2. This hormone regulates fat, protein, and carbohydrate metabolism in our body.
3. If the quantity of iodine in food is lesser than required, then the neck will swell up due to the enlargement of thyroid gland. This deficiency disease is known as goitre. Therefore the iodized salt is advised.
Question-3: What are evergreen plants and deciduous plants? Why do leaves drop off seasonally?
Solution: 1. Evergreen plants are plants that have leaves throughout the year, always green.
2. Deciduous plants are plants which completely lose their leaves during the winter or dry season.
3. The leaves drop off seasonally as they stop producing auxins, which normally prevents the formation of abscission zone that cuts off nutrients and water supply to leaves. Leaves also produce abscisic acid which promotes wilting and falling of leaves.