Karnataka 1st PUC Biology Chapter 19 Important Questions

The endocrine system plays a vital role in controlling growth, metabolism, reproduction and several other body functions. In Karnataka 1st PUC Biology, Chemical Coordination and Integration introduces different endocrine glands, the hormones they release and their effects on the body. Learning hormone functions, feedback mechanisms, and endocrine disorders can be challenging, especially when several concepts need to be remembered together.

The Karnataka 1st PUC Biology Chapter 19 Important Questions help you practise these concepts through focused questions. Regular practice can strengthen your understanding, improve recall and help you prepare accurate answers for the examination.

Important Questions for Karnataka 1st PUC Biology Chapter 19 

Practising questions from Chemical Coordination and Integration can help you revise important concepts and identify topics that need more attention. The following multiple-choice questions cover key areas of the chapter and support your examination preparation.

1. Which hormone regulates the 24-hour circadian rhythm of the human body?

• (A) Epinephrine

• (B) Melatonin

• (C) Gastrin

• (D) Insulin

2. Which glands regulate the calcium (Ca²⁺) level in the blood?

• (A) Thyroid gland

• (B) Parathyroid gland

• (C) Adrenal gland

• (D) Both (A) and (B)

3. Which of the following acts as a second messenger in the mechanism of action of protein hormones?

• (A) Cyclic AMP (cAMP)

• (B) Insulin

• (C) Triiodothyronine (T₃)

• (D) Gastrin

4. Which of the following hormones is glycoprotein in nature?

• (A) Thyroxine

• (B) Follicle-stimulating hormone (FSH)

• (C) Progesterone

• (D) Testosterone

5. Which steroid hormone helps regulate water and electrolyte balance in the human body?

• (A) Insulin

• (B) Melatonin

• (C) Testosterone

• (D) Aldosterone

6. Which part of the digestive system secretes the hormone secretin?

• (A) Stomach

• (B) Oesophagus

• (C) Ileum

• (D) Duodenum

7. Which group of hormones is secreted by the Leydig cells of the testes?

• (A) Androgens

• (B) Estrogens

• (C) Aldosterone

• (D) Gonadotropins

8. Which structure secretes progesterone after ovulation?

• (A) Corpus luteum

• (B) Placenta

• (C) Anterior pituitary gland

• (D) Both (A) and (B)

9. Polydipsia and ketosis are commonly associated with which condition?

• (A) Hypoglycemia

• (B) Cushing's syndrome

• (C) Diabetes insipidus

• (D) Diabetes mellitus

10. Which of the following processes is stimulated by oxytocin released from the posterior pituitary gland?

• (A) Carbohydrate metabolism

• (B) Thyroid gland activity

• (C) Development of secondary sexual characteristics

• (D) Contraction of the uterus

11. Which hormone is released by the atrial walls of the heart and helps lower blood pressure?

• (A) Epinephrine

• (B) Atrial natriuretic factor (ANF)

• (C) Glucagon

• (D) Testosterone

12. Which hormonal imbalance causes Cushing's syndrome?

• (A) Excess secretion of cortisol

• (B) Excess secretion of aldosterone

• (C) Deficiency of cortisone

• (D) Reduced secretion of androgens

13. Which of the following hormones is not secreted by the anterior lobe of the pituitary gland?

• (A) Thyrotropin

• (B) Somatotropin

• (C) Vasopressin

• (D) Prolactin

14. Exophthalmic goitre (Graves' disease) is associated with which condition?

• (A) Hypofunction of the thyroid gland

• (B) Hyperfunction of the thyroid gland

• (C) Hypofunction of the parathyroid gland

• (D) Hyperfunction of the parathyroid gland

15. Congenital hypothyroidism (cretinism) may result in stunted growth, intellectual disability and abnormal skin development in children. Which condition can cause it?

• (A) Cancer of the thyroid gland

• (B) Oversecretion of hormones by the pars distalis

• (C) Iodine deficiency or inadequate thyroid hormone production

• (D) Reduced secretion of growth hormone

Karnataka 1st PUC Biology Chapter 19 Important Questions PDF

Revise key concepts related to endocrine glands, hormone secretion and their functions through these selected questions. Attempt them independently and use the PDF for additional practice before the examination.

Practising the Karnataka 1st PUC Biology Model Question Paper alongside chapter-wise questions can help you understand the paper format and prepare for different types of examination questions.

How to Prepare for Karnataka 1st PUC Biology Chapter 19

Follow these steps to revise Chemical Coordination and Integration and practise examination questions effectively.

• Revise endocrine glands and their hormones: Learn the locations, secretions and functions of the major endocrine glands. Keep the Class 11 Biology syllabus in view while revising the prescribed topics.

• Compare hormone functions: Make short notes on hormones such as insulin, glucagon, thyroxine, cortisol, aldosterone and melatonin, including their roles in the body.

• Understand hormone action: Revise the differences between protein and steroid hormones, their target cells, receptors and second messengers such as cyclic AMP.

• Study endocrine disorders: Learn the causes and symptoms of conditions such as diabetes mellitus, Cushing's syndrome, Graves' disease and hypothyroidism. Practise questions that connect each disorder with the relevant hormone or gland.

• Understand the examination format: Study the Karnataka 1st PUC Exam Pattern and Karnataka PUC 1 syllabus to plan revision according to the prescribed topics and question formats.

• Practise previous examination questions: Solve questions from the Karnataka 1st PUC Mid Term Question Papers to assess your preparation, review mistakes and identify concepts that need further revision.

A clear understanding of Chemical Coordination and Integration comes from revising key concepts and applying them through regular practice. Focus on endocrine glands, hormone functions and related disorders while attempting questions independently. Review your mistakes, revisit difficult topics and continue practising to improve accuracy and build confidence for the Karnataka 1st PUC Biology examination.