Hormones - Types and Functions - UNSOLVED PRACTICE SET

Q7. Distinguish between steroid hormones and peptide hormones with one example of each.

Q8. What is the role of insulin in the human body? What happens when insulin is deficient?

Q9. Why is adrenaline called the "emergency hormone"? Describe one situation where its secretion increases.

Q10. What is the difference between endocrine glands and exocrine glands? Give one example of each.

Q11. Why is iodine essential for the synthesis of thyroxine? What happens when iodine is deficient in the diet?

Q12. During your board exam, you might feel your heart racing and palms sweating. Which hormone is responsible? Explain its effect on the body.

Q13. (a) What are hormones? Describe their general characteristics.

(b) Classify hormones based on their chemical nature. Give two examples of each type.

(c) Why do hormones act on specific target cells even though they are released into the bloodstream?

Q14. (a) Describe the structure and function of insulin. Where is it produced? What type of hormone is it?

(b) Explain the mechanism of action of insulin in regulating blood glucose levels.

(c) A person with Type 1 diabetes needs insulin injections. Why can't insulin be given orally?

(d) What is the difference between Type 1 and Type 2 diabetes?

Q15. (a) Describe the role of the following hormones in the human body:

(i) Thyroxine

(ii) Adrenaline

(iii) Growth hormone (somatotropin)

(iv) Oestrogen

(b) For each hormone, name the gland that secretes it and one disorder caused by its deficiency or excess.

Q16. The following table gives information about some hormones:

(a) Complete the table by filling in all the missing information.

(b) Insulin is a peptide hormone with a molecular mass of about 5808 Da. It consists of two chains: A chain (21 amino acids) and B chain (30 amino acids). How many peptide bonds are present in insulin?

(c) Thyroxine (T₄) contains four iodine atoms. If a person's daily iodine requirement is 150 μg and all of it is used for thyroxine synthesis, how many molecules of thyroxine can be produced? (Molar mass of iodine = 127 g/mol, Avogadro's number = 6.022 × 10²³)

(d) A child with growth hormone deficiency is given synthetic growth hormone. If the treatment starts at age 5 and the child needs 0.3 mg per kg body weight per week, calculate the weekly dose for a 20 kg child.

Q17. Diabetes is a growing health concern in India, with over 70 million people affected.

(a) Explain the difference between Type 1 and Type 2 diabetes in terms of cause, age of onset, and treatment.

(b) A fasting blood glucose level of 126 mg/dL or higher on two separate tests indicates diabetes. If a patient has 5.5 mmol/L of glucose in blood (molar mass of glucose = 180 g/mol), convert this to mg/dL and determine if the patient is diabetic. (1 dL = 100 mL)

(c) The HbA1c test measures average blood glucose over 2-3 months. A reading of 6.5% or higher indicates diabetes. Why does this test measure glucose attached to haemoglobin? What does this tell you about the lifespan of red blood cells?

(d) A diabetic patient is advised to eat foods with low glycemic index (GI). Why are whole wheat chapatis (GI ≈ 62) better than white bread (GI ≈ 75) for diabetics?

(e) Insulin pumps deliver continuous insulin. If a patient needs 40 units of insulin per day and the pump delivers it continuously, how many units per hour does the pump deliver?

Q18. In a school health awareness programme, students prepare a poster on "Hormones and Health."

(a) They include a section on the "fight or flight" response. Draw a flowchart showing how the brain, adrenal gland, and target organs interact during this response. What hormones are released?

(b) A student who plays cricket describes how her heart pounds before facing a fast bowler. Explain the hormonal changes in her body and how they prepare her for action.

(c) The poster mentions that prolonged stress can lead to health problems. How does chronic elevation of cortisol (a stress hormone) affect:

(i) Immune function

(ii) Metabolism

(iii) Sleep patterns

(d) The students distribute iodized salt in a rural area where goitre is common. Explain why iodized salt prevents goitre. How much iodine is typically added to salt (in ppm)?

(e) A classmate asks: "If hormones are so powerful, why do we need such tiny amounts?" Explain the concept of signal amplification in hormone action.