Selina Concise Class 8 Biology Chapter 5 Endocrine System and Adolescence Solution

Selina Concise Class 8 Biology Solution Chapter No. 5- ‘Endocrine System and Adolescence’ For ICSE Board Students.

Selina Concise Biology Solutions for Class 8th Chapter 5 Endocrine System and Adolescence with easy language, expert answers and doubt clearing sections. The book is especially designed keeping in mind the syllabus of ICSE board and the difficulty level faced by the students of ICSE board class 8.

Selina Class 8 Biology Chapter 5 Solution:

Multiple choice questions

1.) Put a tick mark against the correct alternative in the following statements:

(a) Cortisone hormone is secreted by :

(i) Medulla of adrenal (ii) Cortex of adrenal (iii) Pancreas  (iv) Thyroid

Answer: Answer is (ii) Cortex of adrenal, because adrenal gland present on upper side of the kidney which can regulate the stress condition in the body.

 

(b) Which one of the following hormone stimulates the breakdown of glycogen in the liver into glucose?

(i) Insulin (ii) Adrenaline  (iii) Glucagon  (iv) Thyroxine

Answer: Answer is(iii) Glucagon, as it’ll breakdown glycogen into smaller units.

 

(c) Which one of the following hormone converts excess glucose into glycogen ?

(i) Glucagon  (ii) Thyroxine   (iii) Insulin (iv) Adrenaline

Answer: Answer is(iii) Insulin, as it reduces the excess sugar into glycogen to maintain the level of sugar in the body.

 

(d) Which one of the following gland is also called the master gland ?

(i) Pituitary gland   (ii) Adrenal gland   (iii) Thyroid gland   (iv) Ovary

Answer: Answer is (i) Pituitary gland, as it co-ordinates the function of all glands.

 

(e) The emergency hormone to face the danger or to fight is secreted by :

(i) Islets of Langerhans  (ii) Adrenal cortex   (iii) Pituitary  (iv) Adrenal medulla

Answer: Answer is(iv) Adrenal medulla, the emergency hormone is secreted by the adrenaline.

 

(f) Which one of the following endocrine glands produces its hormones in large quantities as a result of emotional stimulation ?

(i) Thyroid  (ii) Islets of Langerhans  (iii) Adrenal medulla  (iv)  Adrenal cortex

Answer: Answer is(iii) Adrenal medulla , it is also secretes the emotion hormone due to emotional stimulation.

(g) In humans, increased thyroxine production results in :

(i) Increased metabolism  (ii) Decreased metabolism  (iii) Dwarfism  (iv) Cretinism

Answer: Answer is (i) Increased metabolism, it leads to increase in heart beat, higher metabolic rate and body heat.

 

Short Answer Questions :

1) What is hormone ?

Answer: Hormone is a chemical secreted by endocrine glands in response to co-ordinate various important function in the body, these hormones circulated through blood and lymph throughout the body and maintain the internal environment of the body constant. They maintain, heat, blood pressure and metabolic rate of the body.

2) Match the items in column A with those in column B.

    Column A                                                                                            Column B

(a) Cretinism    (i) Pituitary gland

(b) Diabetes mellitus                                                             (ii) Abnormal development of infant

(c) Increased metabolic rate                                                 (iii) Over secretion of thyroxine

(d) Simple goitre                                                                  (iv) Insufficient iodine in food

(e) Growth hormone                                                             (v) Insufficient insulin in blood

Answer:

    Column A                                                                                            Column B

(a) Cretinism                                                                     (iv) Insufficient iodine in food

(b) Diabetes mellitus                                                      (v) Insufficient insulin in blood

 

(c) Increased metabolic rate                                                 (iii) Over secretion of thyroxine

(d) Simple goitre      (ii) Abnormal development of infant

(e) Growth hormone                                                          (i)  Pituitary gland

 

3) In table given below, fill in the blanks by naming endocrine glands, the hormones they secrete, and the function they perform in normal person.

Sr. No. Name of the gland Hormones produced Function
1 Thyroid
2 Insulin
3 Prepares the body for action
4 Growth hormone

Answer:

Sr. No. Name of the gland Hormones produced Function
1 Thyroid Thyroxine Consumption of oxygen and metabolism of all cells in the body.
2 Pancreas Insulin Maintain the sugar level.
3 Adrenal gland Adrenaline Prepares the body for action
4 Pituitary Growth hormone For growth

4) Name the source and the function of each of the following hormones :

Hormone Source Function
(a) Glucagon
(b) Thyroxine
(c) Adrenaline
(d) Insulin
(e) Cortisone

Answer:

Hormone Source Function
(a) Glucagon Pancreas Breaks the glycogen into glucose
(b) Thyroxine Thyroid `To take in iodine
(c) Adrenaline Adrenal gland Emotion centre
(d) Insulin Pancreas Maintain sugar level
(e) Cortisone Adrenal cortex Prevents disorder

Long Answer Question (Write the answers in your note book.)

5) What is the difference between an exocrine gland and an endocrine gland ?

Answer:

exocrine gland endocrine gland
Ducts are present. These are duct less gland.
Release enzymes Release hormones.
The response is late or delayed. Gives rapid response.
For example: Adrenal gland For example: Sweat gland

 

6) Why is pituitary gland called the “master gland “ ?

Answer: Yes, pituitary gland called the “master gland “ because this gland have control over all other gland and co-ordinates the major function in the body. This pituitary gland secretes the major hormones in the body and their presence is important in the body. In the absence of such hormones the function cannot be performed by any other hormone or chemical.

7) Briefly write about the importance of physical hygiene during adolescence?

Answer: The importance of physical hygiene during adolescence: The personal hygiene plays a vital role during all the life but specially during adolescence it prevents the infections and damage from certain diseases, such as taking balanced diet fruits, cereals. Regular two times brushing a teeth. Washing hair regularly to prevent hair damage. Cutting the nails regularly to prevent food borne infection.

8) Briefly discuss any four activities which can be practised to overcome stress?

Answer: The activities which can be practised to overcome stress : 1) Regular exercise and maintain the 6 to 8 hours of sleep schedule. 2) Keep yourself away from negative people and negative energy. 3) Maintain the working hours. 4) Do a yoga regularly to keep the mind relax.

Updated: November 13, 2021 — 2:48 pm

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