Selina ICSE Class 10 Biology Solutions Chapter 9 Endocrine Glands

Multiple Choice Type:

Question 1: A gland having endocrine as well as exocrine function is
(a) pituitary
(b) thyroid
(c) pancreas
(d) adrenal

Question 2: Exophthalmic goitre is caused due to the over activity of
(a) thymus
(b) thyroid
(c) parathyroid
(d) adrenal cortex.

Question 3: The secretion of ADH (anti-diuretic hormone) is inhibited by
(a) emotion and stress
(b) nicotine
(c) alcohol
(d) morphine

Very Short Answer Type:

Question 1: Name the following:
(a) The three hormones produced by pancreas
(b) The hormone produced by adrenal medulla
(c) The condition caused by the over secretion of insulin
(d) The hormone secreted by β (beta) cells of the islets of Langerhans
(e) The hormone which increases blood pressure
(f) The hormone causing more urine formation
(g) The hormone which stimulates the entire sympathetic nervous system.
Solution 1:
(a) Insulin, glucagon, somatostatin
(b) Adrenaline
(c) Hypoglycemia
(d) Insulin
(e) Adrenaline
(f) Anti-diuretic hormone (Vasopressin)
(g) Adrenaline

Question 2: What would a child suffer from, if there was hyposecretion from his thyroid?
Solution 2:
If a child’s thyroid gland is hypersecreting, he or she will be diagnosed with cretinism. Dwarfism, mental impairment, retardation and other indications of cretinism might be seen.

Question 3: Choose the odd one out from each series
(a) The glands – thyroid, adrenal, pituitary, prostate
…………………………………………
(b) The conditions – cretinism, myxoedema, goiter, scurvy
………………………………………….
(c) The hormones – insulin, glucagon, cretinism, thyroxine
………………………………………….
(d) The hormonal sources – adrenal cortex, adrenal medualla, cortisone, pituitary.
……………………………………………..
Solution 3:
(a) Prostate
(b) Scurvy
(c) Cretinism
(d) Cortisone

Question 4: Identify the odd one in each of the following and mention what the rest are:
(a) Larynx; glucagon; testosterone; prolactin……………………………………..
(b) Adrenaline; penicillin; insulin; thyroxin…………………………………
(c) Stomach ; ileum; liver; adrenaline…………………………………..
(d) TSH; GH; ADH; Insulin…………………………………….
(e) Iodine, cretinism, goiter, myxedema………………………………….
Solution 4:
(a) Larynx
Cause- The sound box is the larynx, while the other three hormones are glucagon, testosterone, and prolactin.
(b) Penicillin
Cause – Adrenaline, insulin, and thyroxine are hormones, while penicillin is an antibiotic.
(c) Adrenaline
Cause – The stomach, ileum, and liver are digestive system organs, while adrenaline is a hormone.
(d) Insulin
Cause – The pancreas secretes insulin, while the pituitary gland secretes TSH, GH, and ADH hormones.
(e) Iodine
Cause – Iodine is essential for thyroxine hormone production. While thyroxine deficit causes cretinism, goitre, and myxoedema, thyroxine deficiency causes cretinism, goitre, and myxoedema.

Question 5: Match the items of column I with those of column II

Column I	Column II
1. b (beta) cells of islets of Langerhans	(a) condition due to under secretion of  thyroxine in adults
2. Thyroid	(b) Glucocorticoids
3. Cretinism	(c) Exophthalmic goitre
4. Addison’s disease	(d) Increases heart beat
5. Hypothyroidism	(e) Thyroxine
6. Myxoedema	(f) Adrenal cortex
7. Adrenaline	(g) Insulin
8. Cortisone	(h) Under secretion of thyroxine in a child

Solution 5:

Column I	Column II
1. Beta cells of islets of Langerhans	(g) Insulin
2. Thyroid	(c) Exophthalmic goitre
3. Cretinism	(h) Under secretion of thyroxine in a child
4. Addison’s disease	(b) Glucocorticoids
5. Hypothyroidism	(e) Thyroxine
6. Myxoedema	(a) condition due to under secretion of thyroxine in adults
7. Adrenaline	(d) Increases heart beat
8. Cortisone	(f) Adrenal cortex

Question 6: Match the conditions in column A with the cause in column B.

A (Condition)	B (Cause)
(a) Dwarfism and mental retardation	i. shortage of glucose in blood
(b) Diabetes mellitus	ii. Over secretion of growth hormone
(c) Excess of glucose in blood	iii. Insulin shock
(d) Gigantism	iv. Over secretion of thyroxine
(e) Enlargement of breasts in adult males	v. Hypothyroidism
(f) Exophthalmic goitre	vi. Over secretion of cortical hormones

Solution 6:

A (Condition)	B (Cause)
(a) Dwarfism and mental retardation	v. Hypothyroidism
(b) Diabetes mellitus	i. Excess of glucose in blood
(c) Shortage of glucose in blood	iii. Insulin shock
(d) Gigantism	ii. Over secretion of growth hormone
(e) Enlargement of breasts in adult males	vi. Over secretion of cortical hormones
(f) Exophthalmic goitre	iv. Over secretion of thyroxine

Short Answer Type:

Question 1: Mention which of the statements are true (T) and which are false (F). Give reason in support of your answer.
(a) Adrenaline is often described as emergency hormone
(b) There are two kinds of diabetes (mild and severe) related with two different hormones.
(c) Simple goiter can be prevented by using iodised salt in food.
(d) Pituitary is popularly called the master gland
(e) Harmones ‘obey’ the commands like ‘enough, slow down or ‘two little, speed up’.
(f) Gigantism and dwarfirm in humans basically depend on the qualtity and quantity of the food eaten during early growing age.
Solution 1:
(a) True
Cause- Adrenaline is known as the “emergency hormone” because it causes the heart to beat faster, increase breathing, and release more glucose into the bloodstream in order to meet the body’s energy needs in an emergency.
(b) False
Cause – Diabetes insipidus, which is caused by inadequate vasopressin secretion, and diabetes mellitus, which is caused by insulin hyposecretion, are two separate types of diabetes that cannot be classified as moderate or severe.
(c) True
Cause – Iodine is a key component in the formation of the thyroid hormone thyroxine.
(d) True
Cause – All of the other endocrine glands are controlled by the pituitary gland.
(e) True
Reason- Hormones are injected directly into the bloodstream and use chemical mechanisms to affect physiological processes. The feedback system determines their actions.
(f) True
Reason- Gigantism and dwarfism are controlled by the growth hormone from the pituitary gland. Growth hormone is much more active in children for their normal body growth along with which necessary substance required for the synthesis of growth hormone need to be consumed.

Question 2: How do endocrine glands differ from other glands?
Solution 2:
Endocrine glands are ductless glands, which means they release their secretion (hormones) directly into the bloodstream, whereas exocrine glands contain ducts. They release their secretions (not hormones) into the bloodstream via ducts.

Question 3: Mention any two differences between a hormone and an enzyme.
Solution 3:
Hormones: It acts as a catalyst which accelerates the rate of reaction. It is made up of proteins.
Enzyme: It acts as a messenger that triggers the functions in the body. They are not affected by external factors.
Hormones unlike enzymes, are produced only by the endocrine glands. Hormones, unlike enzymes, are injected directly into the bloodstream. Peptides, steroids, and amines are examples of hormones, although all enzymes are proteins.

Question 4: Do you agree with the statement – “ All hormones are chemical signals”? Yes / No . Justify your answer.
Solution 4:
Yes, all hormones are chemical signals. Hormones are peptides, amines, or steroids in their chemical form. They play a role in regulation. The body’s metabolic rate. They have the ability to cause certain chemical changes in the body during the metabolic process. Hormones are so referred to as ‘chemical messengers.’

Question 5: Why is iodine as a nutrient, important to our body?
Solution 5:
Iodine is a key component in the thyroid glands manufacture of the thyroid hormone thyroxine. The thyroxine hormone is a vital hormone in our bodies. A person may suffer from severe disorders if their secretions are abnormal. As a result, it is an essential nutrient for our bodies. These hormones control the body’s metabolism and many other important functions. The body also needs thyroid hormones for proper bone and brain development.

Question 6: If you stand to make your maiden speech before a large audience your mouth dries up and heart rate increases. What brings about these changes?
Solution 6:
During this type of situation, a hormone adrenaline that prepares the body for any type of emergency. The hormone adrenaline causes the heart to beat quicker. Simultaneously, it causes the arterioles of the digestive system to contract, limiting the blood supply to the digestive system and making the mouth dry.

Question 7: If one adrenal gland is removed, the other one gets enlarged to some extent. How do you explain this change?
Solution 7:
When one of the adrenal glands is removed, the other enlarges. This is to ensure that the body’s hormone requirements are met. Other glands become a little enlarging as a whole.
Given that one of the two adrenal glands has entirely disappeared.
When one of the adrenal glands is removed, the other enlarges.

Question 8: Name the two kinds of diabetes? Mention their symptoms and the causes.
Solution 8:
Two kind of Diabetes are: 1. Diabetes mellitus 2. Diabetes insipidus
Diabetes mellitus: Cause – Insulin hormone secretion is inhibited
Symptoms – Person feels thirsty and loses weight due to the discharge of a large amount of urine laced with sugar. In severe circumstances, the person’s vision may be lost.
Diabetes insipidus: Cause – Anti-diuretic hormone is being secreted.
Symptoms – Urination on a regular basis causes a loss of fluids in the body, making the person thirsty.

Question 9: People living in the low Himalayan hilly regions often suffer from goiter. What could be the possible reason for it?
Solution 9:
Iodine deficiency exists in Himalayan soil. As a result, food grown on such soil is lacking in iodine. As a result, when Himalayans consume iodine-deficient diet, they do not receive adequate iodine consumption. As a result, goitre is common among persons living in the low Himalayan hilly regions.

Question 10: Given below is a table designed to give the names of the glands, the hormones produced, their chief functions, the effects of over secretion and under secretion in respect of thyroid, pituitary and pancreas.
Fill up the blanks 1-13

Sl. No.	Source Gland cells	Hormone produced	Chief function	Effect of over secretion	Effect of under secretion
1.	(1) ……….	thyroxine	(2) ……….	(3) ……….	(4) ……….
2.	Beta cells of Islets of Langerhans	(5) ……	Promotes glucose utilization by the body cells	(6) ……….	(7) ……….
3.	(8) ……….	Growth hormone	(9) ……….	(10) ……….	Dwarfism
4.	(11) ……	Vasopressin	Increases reabsorption of water from kidney tubule	(12) ……….	(13) ……….

Solution 10:

Sl. No.	Source Gland cells	Hormone produced	Chief function	Effect of over secretion	Effect of under secretion
1.	Thyroid	thyroxine	Regulates basal metabolism	Exophthalmic goiter	Simple goiter, cretinism in children and myxoedema in adults
2.	Beta cells of Islets of Langerhans	Insulin	Promotes glucose utilization by the body cells	Hypoglycemia	Diabetes mellitus
3.	Anterior pituitary	Growth hormone	Promotes growth of the whole body	Gigantism	Dwarfism
4.	Posterior pituitary	Vasopressin	Increases reabsorption of water from kidney tubule	More concentrated and less amount of urine	Diabetes insipidus

Question 11: Complete the following table by filling in the blanks numbers 1 to 7?

Gland	Hormone secreted	Effect on body
(1) ……….	(2) ……….	Regulates basal metabolism
Pancreas (“beta” cells)	(3) ……….	Controls blood sugar level
(4) ……….	(5) ……….	Increases heart beat
(6) ……….	Thyroid stimulating hormone	(7) ……….

Solution 11:

Gland	Hormone secreted	Effect on body
Thyroid	Thyroxine	Regulates basal metabolism
Pancreas (“beta” cells)	Insulin	Controls blood sugar level
Adrenal gland	Adrenaline	Increases heart beat
Anterior pituitary	Thyroid stimulating hormone	Stimulates thyroxine secretion

Question 12: Complete the following table by filling in the blank spaces numbered 1 to 8:

Gland	Secretions	Effect on body
(1) ………..	oestrogen	(2) ………..
Alpha cells of islets of Langerhans	(3) ………..	(4) ………..
(5) ………..	(6) ………..	Protruding eyes
(7) ………..	(8) ………..	Gigantism

Solution 12:

Gland	Secretions	Effect on body
Ovary	oestrogen	development of secondary sexual characteristics
Alpha cells of islets of Langerhans	Glucagon	Raises blood sugar level
Thyroid	Hypersecretion of thyroxine	Protruding eyes
Anterior pituitary	Hypersecretion of Growth hormone	Gigantism

Long Answer Type:

Question 1: Compare the hormonal response with the nervous response with respect to their speed, transmission and the general nature of changes brought about.
Solution 1:

Hormonal Response	Nervous Response
Hormonal response takes a long time.	The nervous reaction is instantaneous.
Hormones are chemical messengers that circulate through the body.	Nerve impulses are conveyed across nerve fibres as electro-chemical reactions.
This reaction causes particular chemical changes. As a result, it modulates metabolism.	During metabolism, this reaction causes no chemical changes.

Question 2: Mention three important differences between the action of hormones and that of nerves in the regulatory mechanism of our body.
Solution 2:

Action of Hormones	Action of Nerves
Hormones have a wide range of effects in the body. They can have an effect on multiple target sites at the same time.	Only certain glands are affected by the nerve response.
Hormones can have a short-term or long-term effect.	Nervous responses always have a short-term effect.
Previous learning experiences have no effect on this.	Previous learning experiences may influence the outcome.

Structured / Application/ Skill Type:

Question 1: Study the diagram given below and then answer the questions that follow:

(a) Name the cells of the pancreas that produce (1) glucagon (2) Insulin
(b) state the main function of (1) glucagon and (2) insulin
(c) Why is the pancreas referred to as an exo-endocrine gland?
(d) why is insulin not given orally but in injected into the body:
(e) What is the technical term for the cells of the pancreas that produce endocrine hormones?
(f) where in the body is the pancreas located?
Solution 1:
a. Glucagon: Alpha cells of the Langerhans islets Insulin is produced by beta cells in the Langerhans islets.
b. Insulin is a hormone that keeps blood glucose (sugar) levels stable.
Glucagon stimulates the breakdown of glycogen into glucose in the liver, which boosts blood glucose levels.
c. An endocrine gland produces secretions that are not poured into a duct, whereas an exocrine gland produces secretions that are poured into a channel. The pancreas is classified as an endocrine gland since it generates hormones such as insulin, glucagon, and somatostatin directly into the bloodstream rather than through a duct. It is an exocrine gland since it secretes pancreatic secretions for digesting through a duct. As a result, the pancreas is classified as an exo-endocrine gland.
d. Insulin is not given orally since it is degraded by the digestive acids and so rendered ineffective in the body.
e. Langerhans Islets
f. The pancreas is placed behind the stomach in the abdomen.

Question 2: Given alongside is a portion from the human body showing some important structure in ventral (front) view.
(a) Where is this portion located in the body?
(b) Name the structure numbered 1 – 3
(c) state one main function of each of the structure named above.
(d) Is there any duct to carry the secretions from the structure numbered 2? If so, give its name.
Solution 2:
(a) This section is placed above the sternum in the neck.
(b) Larynx #1, Thyroid gland #2, Trachea #3
(c) The larynx is the voice box that houses the vocal chords. It aids in the production of sound. Thyroxine and calcitonin, two important hormones, are produced by the thyroid gland.
The wind pipe, or trachea, aids in the passage of air to and from the respiratory system during breathing.
(d) The thyroid gland is the second structure. Because it is an endocrine gland, it is ductless and secretes directly into the bloodstream. As a result, there is no duct.

Question 3: Given alongside is an outline diagram of human body showing position of certain organs.
(a) Name the parts numbered 1 to 4
(b) what is common to all these parts in regard to the nature of their functions?
(c) Name the nutrient element which is essential for the normal working of part 2.

Solution 3:
(a) 1- Pituitary gland, 2 – thyroid gland, 3 – pancreas, 4 – adrenal glands
(b) The glands depicted in the diagram are all endocrine glands. They produce vital hormones and secrete them directly into the bloodstream.
(c) Iodine is required for thyroxine to function properly.

Question 4: Given below are two diagram (one is correct the other is some hwat incorrect) showing the transport of a hormone from its source gland/ cell to the target organ/ cell.
(a) which one has the error A or B? ……………
(b) what is the error? …………………

Solution 4:
(a) A
(b) Hormone released by the endocrine gland is shown in image A travelling in only one direction, that is, towards the target organ. However, hormones injected into the bloodstream may have one or multiple target sites at any given time. The blood carries the arrows to all regions of the body, but their influence is only felt in one or more of them.