NCERT Solutions for Class 11 Biology Chapter 19 Chemical Coordination and Integration

NCERT Solutions for Class 11 Biology Chapter 19 Chemical Coordination and Integration

Irshad AnwarUpdated on 14 Aug 2025, 11:09 AM IST

The NCERT Solutions for Class 11 Biology Chapter 19 Chemical Coordination and Integration explains about hormones. Hormones play a very important role in the human body. They maintain balance by controlling functions such as metabolism, growth, and reproduction. Unlike the nervous system, which communicates through electrical impulses, the endocrine system communicates by releasing hormones. The NCERT solutions are prepared by subject experts in easy and clear language.

This Story also Contains

  1. Download PDF of NCERT Solutions for Class 11 Biology Chapter 19
  2. NCERT Solutions for Class 11 Biology Chapter 19 (Exercise Questions)
  3. Approach to solve Class 11 Biology Chapter 19 Question Answer
  4. Important Question from Class 11 Biology Chapter 19 Solutions
  5. What Extra Should Students Study Beyond the NCERT for NEET?
  6. NCERT Solutions for Class 11 Biology Chapterwise
NCERT Solutions for Class 11 Biology Chapter 19 Chemical Coordination and Integration
NCERT Solutions for Class 11 Biology Chapter 19 Chemical Coordination and integration

Class 11 Biology Chapter 19 Solutions includes how the human body achieves balance through hormones. With the help of well-labelled diagrams, students can understand the concepts faster. This is an important chapter for school exams and competitive exams like NEET. Students can also download the Chemical Coordination and Integration NCERT PDF to do offline revision.

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Download PDF of NCERT Solutions for Class 11 Biology Chapter 19

Download the PDF given below to easily learn the answers related to hormones and their functions. This will help you revise faster and understand key concepts clearly. The NCERT Class 11 Solutions are prepared by subject experts and help in improving the performance of the students.

Download PDF

NCERT Solutions for Class 11 Biology Chapter 19 (Exercise Questions)

The solved exercise questions provided below help students understand how the endocrine system functions. It also explains how hormones regulate various activities in the human body. Studying through the Class 11 Biology Chapter 19 question answer allows students to understand each concept clearly.

Q1. Define

(a) Exocrine gland

Answer:

Exocrine gland-

The glands that discharge their secretions into ducts are known as exocrine glands. Examples of exocrine glands include the sebaceous gland in the skin, the salivary gland in the buccal cavity, etc.

Q1. Define

(b) Endocrine gland

Answer:

Endocrine glands-

The glands that do not discharge their secretions into ducts are known as endocrine glands. These glands discharge their secretions directly into the blood. Examples of endocrine glands include the Pituitary gland, thyroid gland, adrenal gland, etc.

Q1. Define

(c) Hormone

Answer:

Hormones-

The hormones are chemical messengers that regulate physiological processes in living organisms. They act upon specific cells/tissues/organs.

Q2. Diagrammatically indicate the location of the various endocrine glands in our body.

Answer:

The location of the various endocrine glands in our body is depicted below

location of endocrine glands

Q3. List the hormones secreted by

(a) Hypothalamus

Answer:

The hormones secreted by the hypothalamus are divided into two groups

(1) Releasing hormones: These include gonadotropin-releasing hormone, thyrotropin-releasing hormone, somatotropin-releasing hormone, adrenocorticotrophin-releasing hormone

(2) Inhibiting hormones: These include somatostatin, growth-inhibiting hormone, melanocyte-inhibiting hormone

Q3. List the hormones secreted by

(b) Pituitary

Answer:

The pituitary gland has two components i.e., adenohypophysis and neurohypophysis.

Hormones secreted by the adenohypophysis are growth hormone (GH), prolactin, thyroid-stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), melanocyte-stimulating hormone (MSH)

Hormones secreted by the neurohypophysis are oxytocin and vasopressin

Q3. List the hormones secreted by

(c) Thyroid

Answer:

Thyroid gland- The thyroid gland secretes three hormones namely, thyroxin, triiodothyronine, and calcitonin.

Q3. List the hormones secreted by

(d) Parathyroid

Answer:

Parathyroid Gland- It secretes parathyroid hormone

Q3. List the hormones secreted by

(e) Adrenal

Answer:

Adrenal gland - The adrenal gland is divided into two parts, the outer adrenal cortex and the inner adrenal medulla.

Hormones of the adrenal cortex include aldosterone and cortisol.

Hormones of the adrenal medulla are adrenaline and noradrenaline.

Q3. List the hormones secreted by

(f) Pancreas

Answer:

Pancreas: Hormones secreted by the pancreas are insulin and glucagon.

Q3. List the hormones secreted by

(g) Testis

Answer:

Testis: The hormone secreted by the testis is testosterone.

Q3. List the hormones secreted by

(h) Ovary

Answer:

Ovary: The hormone secreted by the ovary includes estrogen and progesterone.

Q3. List the hormones secreted by

(i) Thymus

Answer:

Thymus: Hormones secreted by the thymus are thymosins.

Q3. List the hormones secreted by

(j) Atrium

Answer:

Atrium: The walls of the atrium secrete atrial natriuretic factor.

Q3. List the hormones secreted by

(k) Kidney

Answer:

Kidney: The hormone secreted by the kidney is erythropoietin.

Q3. List the hormones secreted by

(l) G-I Tract

Answer:

G-l tract- The hormones secreted by the G-l tract are Gastrin, secretin, cholecystokinin (CCK), and gastric inhibitory peptide (GIP).

Q4. Fill in the blanks:

Hormones Target gland
(a) Hypothalamic hormones __________________
(b) Thyrotrophin (TSH) __________________
(c) Corticotrophin (ACTH) __________________
(d) Gonadotrophins (LH, FSH) __________________
(e) Melanotrophin (MSH) __________________

Answer:

Hormones Target gland
(a) Hypothalamic hormones Pituitary gland
(b) Thyrotrophin (TSH) Thyroid gland
(c) Corticotrophin (ACTH) Adrenal cortex
(d) Gonadotrophins (LH, FSH) Testis and ovaries
(e) Melanotrophin (MSH) Pigment cells of the dermis of the skin

Q5. Write short notes on the function of

(a) Parathyroid hormone (PTH)

Answer:

Function of Parathyroid hormone (PTH):

  • The parathyroid hormone maintains the calcium levels in the body.
  • It increases the calcium levels of the blood.
  • It stimulates bone resorption which demineralises bones increasing blood calcium levels.
  • It also stimulates calcium absorption by renal tubules and from the digested food.

Q5. Write short notes on the function of

(b) Thyroid hormone

Answer:

Functions of Thyroid hormones are given below:

Thyroxine/tetraiodothyronine (T4):

  • It regulates the basal metabolic rate (BMR).
  • It regulates body growth such as the ossification of bones and mental development.
  • It controls body weight.
  • It also controls tissue differentiation and metamorphosis of the tadpole larva into an adult frog.

Tri-iodothyronine (T3):

  • It increases the body's oxygen and energy consumption.
  • It increases the heart rate and force of contraction which increases the cardiac output.

Q5. Write short notes on the function of

(c) Thymosin

Answer:

The function of Thymosins is given below:

  • Thymosin stimulates the differentiation of T-lymphocytes and provides cell-mediated immunity.
  • It promotes the production of antibodies to provide humoral immunity.
  • It also stimulates the rate of cell division in kids and hence promotes growth.

Q5. Write short notes on the function of

(d) Androgens

Answer:

The functions of Androgens are given below:

Testosterone:

  • Testosterone helps in the maturation of sperm.
  • It stimulates the growth and development of the male reproductive system.
  • It stimulates the development of secondary sexual characteristics such as a beard and a moustache.
  • It produces anabolic effects on protein and carbohydrate metabolism.

Androsterone (Weaker androgen):

It affects the masculinisation of the foetus and child and maintains or creates masculine traits in adults.

Q5. Write short notes on the function of

(e) Estrogen

Answer:

The primary function of estrogens is the development of female secondary sexual characteristics. These include breasts, endometrium, regulation of the menstrual cycle, etc. In males, estrogen helps in the maturation of the sperm and the maintenance of a healthy libido.

Q5. Write short notes on the function of

(f) Insulin and Glucagon

Answer:

The functions of Insulin and Glucagon are given below:

Insulin:

  • It plays a major role in the regulation of glucose homeostasis.
  • It acts on hepatocytes and adipocytes.
  • It stimulates the transport of glucose from the blood to muscle.
  • It promotes the oxidation of glucose and the conversion of glucose to glycogen, i.e. glycogenesis, resulting in hypoglycemia.

Glucagon:

  • It plays a major role in the maintenance of normal blood glucose levels.
  • It acts on hepatocytes and stimulates the conversion of glycogen into glucose.
  • It also stimulates the process of gluconeogenesis, i.e. the conversion of non-carbohydrate substances such as fats and proteins to glucose.

Q6. Give example(s) of

(a) Hyperglycemic hormone and hypoglycemic hormone

Answer:

Hyperglycemic hormone - glucagon

Hypoglycemic hormone - insulin

Q6. Give example(s) of

(b) Hypercalcemic hormone

Answer:

Parathormone hormone

Q6. Give example(s) of

(c) Gonadotrophic hormone

Answer:

Luteinising hormone (LH)

Follicle-stimulating hormone (FSH)

Q6. Give example(s) of

(d) Progestational hormone

Answer:

Progesterone

Q6. Give example(s) of

(e) Blood pressure-lowering hormone

Answer:

Atrial natriuretic factor

Q6. Give example(s) of

(f) Androgens and estrogens

Answer:

Androgens: Testosterone and androsterone

Estrogens : β-oestradiol

Q7. Which hormonal deficiency is responsible for

(a) Diabetes Mellitus

Answer:

Insufficient secretion of insulin is responsible.

Q7. Which hormonal deficiency is responsible for the

(b) Goitre

Answer:

Insufficient secretion of thyroxin is responsible.

Q7. Which hormonal deficiency is responsible for the

(c) Cretinism

Answer:

Insufficient secretion of thyroxine is responsible.

Q8. Briefly mention the mechanism of action of FSH.

Answer:

Follicle-stimulating hormone (FSH) is a glycoprotein polypeptide hormone. It is insoluble in lipids and hence cannot enter the target cell. This hormone binds to the cell surface and activates cellular systems to perform functions.

Steps in the action of FSH:

  • A molecule of FSH binds to the receptor protein present on the cell surface and forms the hormone-receptor complex.
  • The formation of a hormone-receptor complex activates the enzyme adenyl cyclase.
  • Adenyl cyclase converts ATP into cyclic AMP (cAMP) as a second messenger.
  • cAMP activates the follicular cells of membrane granulose to secrete estrogens.
Q9. Match the following:
Column I

Column II

(a) T4

(i) Hypothalamus

(b) PTH

(ii) Thyroid

(c) GnRH

(iii) Pituitary

(d) LH

(iv) Parathyroid

Answer:

Column IColumn II
(a) T4

(ii) Thyroid

(b) PTH

(iv) Parathyroid

(c) GnRH

(i) Hypothalamus

(d) LH

(iii) Pituitary


NCERT Solutions for Class 11: Subject-wise

Approach to solve Class 11 Biology Chapter 19 Question Answer

To solve the textbook questions effectively, one needs to understand the concepts first. The chapter has terms, such as the endocrine system and the human endocrine system. The Chemical Coordination and Integration NCERT PDF has all the solved exercise questions. It includes all the to-the-point answers and necessary information. Making notes of the chapter is really important, highlighting all the important points. Finally, one should practice the NCERT Solutions Class 11 Biology to have an overall idea and build confidence before the exams.

Check NCERT Books and NCERT Syllabus here:

Important Question from Class 11 Biology Chapter 19 Solutions

Hormones play a major role in controlling various functions in our body, from growth to metabolism. The question below highlights important topics that are often asked in exams. For more different types of questions, students can depend on Chemical Coordination and Integration Class 11 Solutions.

Question: The biomolecule that cannot act as a chemical messenger [hormone] is

Options:

  • Proteins
  • Steroids
  • Fatty acids
  • Carbohydrates

Answer: The correct answer is option 4)Carbohydrates.

Explanation:

Carbohydrates cannot act as chemical messengers or hormones. Proteins, steroids, and fatty acids are all examples of biomolecules that can act as hormones or chemical messengers. Proteins can act as hormones, such as insulin and growth hormone, while steroid hormones are derived from cholesterol and include hormones such as testosterone and cortisol. Fatty acids can also act as hormones, such as prostaglandins.

What Extra Should Students Study Beyond the NCERT for NEET?

Studying concepts beyond the NCERT will help in answering application-based questions. Referring to Class 11 Biology Chapter 19 Solutions improves the performance in competitive exams or school exams. Some extra concepts that can be studied are:


Frequently Asked Questions (FAQs)

Q: How does the endocrine system regulate chemical coordination in humans?
A:

The endocrine system controls chemical coordination by secreting hormones into the blood as explained in Chemical Coordination and Integration Class 11 Solutions. The hormones affect specific organs and regulate functions such as growth, metabolism, and reproduction. 

Q: What are the major endocrine glands discussed in NCERT Class 11 Biology Chapter 19?
A:

The chief endocrine glands discussed in Class 11 Biology Chapter 19 Solutions are the hypothalamus, pituitary, thyroid, parathyroid, adrenal glands, pancreas, and gonads (testes and ovaries). All these glands release certain hormones that help in maintaining body functions.

Q: Explain the role of hormones in chemical coordination.
A:

According to NCERT Solutions for Class 11 Biology Chapter 19 Chemical Coordination and Integration, hormones are chemical messengers that regulate numerous body functions. They decide metabolism, growth, reproduction, response to stress, and homeostasis by communicating with target cells.

Q: What are the major disorders caused by hormonal imbalance?
A:

Disorders resulting from hormonal imbalance include diabetes (caused by the lack of insulin), hypothyroidism (thyroid hormones are below normal), hyperthyroidism (thyroid hormones are in excess), and gigantism (growth hormone in excess). This hormonal imbalance is explained in detail in the NCERT Solutions for Class 11 Biology Chapter 19 Chemical Coordination and Integration. 

Q: What is Chemical Coordination and Integration in Class 11 Biology?
A:

Chemical coordination and integration are the use of hormones in regulating body functions. It is regulated by the endocrine system, which releases hormones to provide balance and coordination in the body.

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