Which of the following are associated with deficiency of thyroid hormones? 1. Cretinism occurs when deficiency happens in old age. 2. Goitre formation due to iodine deficiency. 3. It ensures perfectly regular menstrual cycles. Select the correct answer using the code below:

Correct Option The correct option is 2 only Explanation The thyroid gland secretes hormones, primarily Thyroxine (T4) and Triiodothyronine (T3), which regulate the basal metabolic rate (BMR), growth, and development. Iodine is essential for the synthesis of these hormones. Disorders of the thyroid are classified into hypothyroidism (deficiency) and hyperthyroidism (excess). Statement-wise Analysis - Statement 1 is Incorrect: Iodine is required for the synthesis of thyroid hormones. A dietary deficiency of iodine results in low levels of T3 and T4. This stimulates the anterior pituitary to release increased amounts of Thyroid Stimulating Hormone (TSH). The constant stimulation causes the thyroid gland to enlarge, resulting in simple goitre. - Statement 2 is Correct: Cretinism is a disorder caused by hypothyroidism (deficiency of thyroid hormone) during pregnancy or infancy. It leads to stunted physical growth and mental retardation. Deficiency of thyroid hormones in adults causes Myxedema, characterized by lethargy and tissue swelling, not Cretinism. - Statement 3 is Incorrect: Thyroid hormones play a vital role in maintaining the physiology of the reproductive system. Deficiency of these hormones (hypothyroidism) leads to menstrual irregularities (such as oligomenorrhea or menorrhagia), rather than ensuring regular cycles. Key Takeaway: Iodine deficiency causes Goitre. Hypothyroidism leads to Cretinism in children and Myxedema in adults, and it disrupts menstrual regularity in females.

NCERT Class 11 Science — Chapter 9: Chemical Coordination and Integration

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Which of the following are associated with deficiency of thyroid hormones?

Cretinism occurs when deficiency happens in old age.
Goitre formation due to iodine deficiency.
It ensures perfectly regular menstrual cycles.

Select the correct answer using the code below:

Official previous-year question

Verified 1 Aug 2026.

Options

A1 and 3 only
B2 only
C1 only
D1, 2 and 3

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Solution

Correct Option

The correct option is

2 only

Explanation

The thyroid gland secretes hormones, primarily Thyroxine (T₄) and Triiodothyronine (T₃), which regulate the basal metabolic rate (BMR), growth, and development. Iodine is essential for the synthesis of these hormones. Disorders of the thyroid are classified into hypothyroidism (deficiency) and hyperthyroidism (excess).

Statement-wise Analysis

Statement 1 is Incorrect: Iodine is required for the synthesis of thyroid hormones. A dietary deficiency of iodine results in low levels of T₃ and T₄. This stimulates the anterior pituitary to release increased amounts of Thyroid Stimulating Hormone (TSH). The constant stimulation causes the thyroid gland to enlarge, resulting in simple goitre.
Statement 2 is Correct: Cretinism is a disorder caused by hypothyroidism (deficiency of thyroid hormone) during pregnancy or infancy. It leads to stunted physical growth and mental retardation. Deficiency of thyroid hormones in adults causes Myxedema, characterized by lethargy and tissue swelling, not Cretinism.
Statement 3 is Incorrect: Thyroid hormones play a vital role in maintaining the physiology of the reproductive system. Deficiency of these hormones (hypothyroidism) leads to menstrual irregularities (such as oligomenorrhea or menorrhagia), rather than ensuring regular cycles.

Key Takeaway: Iodine deficiency causes Goitre. Hypothyroidism leads to Cretinism in children and Myxedema in adults, and it disrupts menstrual regularity in females.

Your note

More from Chapter 9: Chemical Coordination and Integration

Consider the following statements about the thyroid gland: 1. It consists of a single lobe located on the trachea. 2. Follicular cells synthesize thyroxine (T4) and triiodothyronine (T3). 3. Iodine is essential for the normal rate of hormone synthesis. Which of the statements given above are correct?

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Regarding exophthalmic goitre (Graves' disease), which of the following is/are correct? 1. It is a form of hyperthyroidism. 2. It involves sinking of the eyeballs. 3. It is characterised by an increased basal metabolic rate. Select the correct answer using the code below:

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Assertion (A): Thyrocalcitonin (TCT) helps regulate blood calcium levels. Reason (R): Parathyroid hormone (PTH) acts on bones to stimulate bone resorption.

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With reference to parathyroid hormone (PTH), consider the following statements: 1. Its secretion is regulated by circulating sodium levels. 2. It increases bone resorption and renal reabsorption of calcium. 3. It increases calcium absorption from the digested food. Which of the statements given above are correct?

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Which of the following are typical effects of catecholamines released from the adrenal medulla? 1. They decrease heart rate and strength of cardiac contraction. 2. Increased alertness and pupillary dilation. 3. Reduced respiratory rate and glycogen synthesis. Select the correct answer using the code below:

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Correct Option

The correct option is

2 only

Explanation

Statement-wise Analysis

Statement 1 is Incorrect: Iodine is required for the synthesis of thyroid hormones. A dietary deficiency of iodine results in low levels of T₃ and T₄. This stimulates the anterior pituitary to release increased amounts of Thyroid Stimulating Hormone (TSH). The constant stimulation causes the thyroid gland to enlarge, resulting in simple goitre.
Statement 2 is Correct: Cretinism is a disorder caused by hypothyroidism (deficiency of thyroid hormone) during pregnancy or infancy. It leads to stunted physical growth and mental retardation. Deficiency of thyroid hormones in adults causes Myxedema, characterized by lethargy and tissue swelling, not Cretinism.
Statement 3 is Incorrect: Thyroid hormones play a vital role in maintaining the physiology of the reproductive system. Deficiency of these hormones (hypothyroidism) leads to menstrual irregularities (such as oligomenorrhea or menorrhagia), rather than ensuring regular cycles.

Key Takeaway: Iodine deficiency causes Goitre. Hypothyroidism leads to Cretinism in children and Myxedema in adults, and it disrupts menstrual regularity in females.