NCERT Exemplar Solutions for Class 11 Biology Chapter 22 Chemical Coordination and Integration
The NCERT Exemplar Solutions for Class 11 Biology Chapter 22, Chemical Coordination and Integration, focus on the endocrine system and how hormones regulate various body functions. Unlike the nervous system, which controls activities through electrical impulses, the endocrine system ensures coordination via chemical messengers called hormones. This chapter introduces students to different endocrine glands, their secretions, mechanisms of hormone action, and associated disorders. The NCERT Exemplar questions are designed to deepen understanding, improve analytical skills, and prepare students for board exams and competitive tests like NEET. The chapter begins with an introduction to the endocrine system, which includes glands such as the pituitary, thyroid, parathyroid, adrenal, pancreas, and gonads. Each gland secretes specific hormones that influence growth, metabolism, reproduction, and homeostasis. Exemplar questions often involve matching glands with hormones or predicting outcomes of hormonal imbalances.
The pituitary gland, also known as the master gland, plays a central role by secreting hormones like growth hormone, prolactin, TSH, ACTH, FSH, and LH. These hormones regulate other endocrine glands. Exemplar questions often test how pituitary hormones control different physiological processes.
The thyroid gland secretes thyroxine, which regulates metabolism and growth. Disorders such as goiter, hypothyroidism, and hyperthyroidism are explained. Exemplar problems may ask students to reason about symptoms of thyroid imbalance or analyze iodine deficiency effects.
The parathyroid glands secrete parathyroid hormone (PTH), which regulates calcium and phosphate balance. Exemplar questions in this section often require application of concepts, such as predicting changes in blood calcium levels if PTH secretion is altered.
The adrenal glands are divided into the adrenal medulla and the adrenal cortex. The medulla secretes adrenaline and noradrenaline, which prepare the body for stress, while the cortex secretes corticosteroids that regulate metabolism, immune response, and water balance. Exemplar questions frequently test students on differentiating between these hormones and their roles.
The pancreas functions as both an exocrine and an endocrine gland. Its endocrine part secretes insulin and glucagon, which regulate blood sugar levels. Exemplar questions may ask students to explain the role of insulin in diabetes mellitus.
The gonads, including testes and ovaries, secrete sex hormones like testosterone, estrogen, and progesterone, which control reproductive functions. Exemplar questions often involve analyzing how these hormones affect secondary sexual characteristics. The chapter also covers the mechanism of hormone action, explaining how peptide hormones act through secondary messengers and how steroid hormones directly regulate gene expression. Exemplar questions in this section are usually reasoning-based and test higher-order thinking skills. The chapter concludes with common endocrine disorders such as diabetes, Addison’s disease, and Cushing’s syndrome. Exemplar questions often ask about symptoms, causes, and treatments, connecting biological knowledge with medical relevance. To prepare thoroughly, students should review diagrams of glands and flowcharts from the NCERT textbook. Practicing NCERT Exemplar questions strengthens conceptual understanding and builds confidence for exams. In conclusion, NCERT Exemplar Solutions for Class 11 Biology Chapter 22 Chemical Coordination and Integration provide a comprehensive study of hormones and the endocrine system. By solving Exemplar problems, students enhance their grasp of biology, sharpen their reasoning abilities, and prepare effectively for both board and entrance examinations.