KnowledgeBoat Logo
OPEN IN APP

Chapter 5

Endocrine System and Adolescence

Class 8 - Concise Biology Selina


Multiple Choice Questions

Question 1

Cortisone hormone is secreted by :

  1. Medulla of adrenal
  2. Cortex of adrenal
  3. Pancreas
  4. Thyroid

Answer

Cortex of adrenal

Reason — The adrenal cortex secretes Cortisone.

Question 2

Which one of the following hormones stimulates the breakdown of glycogen in the liver into glucose?

  1. Insulin
  2. Adrenaline
  3. Glucagon
  4. Thyroxine

Answer

Glucagon

Reason — Glucagon stimulates the breakdown of glycogen in the liver to glucose.

Question 3

Which one of the following hormones converts excess of glucose into glycogen

  1. Glucagon
  2. Thyroxine
  3. Insulin
  4. Adrenaline

Answer

Insulin

Reason — Insulin converts extra glucose to glycogen which is ultimately stored in the liver and muscles.

Question 4

Which one of the following glands is also called the master gland :

  1. Pituitary gland
  2. Adrenal gland
  3. Thyroid gland
  4. Ovary

Answer

Pituitary gland

Reason — Pituitary gland regulates the activity of other endocrine glands. So, it is also called the "master gland".

Question 5

The emergency hormone to face the danger or to fight is secreted by;

  1. Islets of Langerhans
  2. Adrenal cortex
  3. Pituitary
  4. Adrenal medulla

Answer

Adrenal medulla

Reason — Adrenaline hormone is also called the "fight or flight hormone". It is secreted by Adrenal medulla.

Question 6

Which one of the following endocrine glands produces its hormone in large quantities as a result of emotional stimulation?

  1. Thyroid
  2. Islets of Langerhans
  3. Adrenal medulla
  4. Adrenal cortex

Answer

Adrenal medulla

Reason — Adrenal medulla secretes adrenaline (also called epinephrine or emergency hormone). This hormone is secreted when a person is under severe stress (physical or emotional).

Question 7

In humans, increased thyroxine production results in:

  1. Increased metabolism
  2. Decreased metabolism
  3. Dwarfism
  4. Cretinism

Answer

Increased metabolism

Reason — Oversecretion of thyroxine causes an increased metabolic rate.

Short Answer Questions

Question 1

What is a hormone?

Answer

Hormone is a chemical substance secreted by an endocrine gland, which is directly poured into the blood stream and acts on a target organ or cell.

Question 2

Match the items in Column A with those in Column B.

Column AColumn B
CretinismPituitary Gland
Diabetes MellitusAbnormal development of infant
Increased metabolic rateOversecretion of thyroxine
Simple goitreInsufficient iodine in food
Growth hormoneInsufficient insulin in blood

Answer

Column AColumn B
CretinismAbnormal development of infant
Diabetes MellitusInsufficient insulin in blood
Increased metabolic rateOversecretion of thyroxine
Simple goitreInsufficient iodine in food
Growth hormonePituitary gland

Question 3

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

S.No.Name of the glandHormone producedFunction
1.Thyroid..............................
2................Insulin...............
3...............................Prepares the body for action
4................Growth Hormone...............

Answer

S.NoName of the glandHormone producedFunction
1.ThyroidThyroxineControl of metabolic rate
2.PancreasInsulinRegulation of sugar in blood.
3.Adrenal MedullaAdrenalinePrepares the body for action
4.PituitaryGrowth HormoneSpeeds up growth

Question 4

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

 HormoneSourceFunction
(a)Glucagon..............................
(b)Thyroxine..............................
(c)Adrenaline..............................
(d)Insulin..............................
(e)Cortisone..............................

Answer

 HormoneSourceFunction
(a)GlucagonPancreasBreakdown of glycogen to glucose. Raises sugar in the blood.
(b)ThyroxineThyroid glandControl of metabolic Rate .
(c)AdrenalineAdrenal MedullaPrepare the body to face emergency, stress.
(d)InsulinPancreasRegulation of sugar in blood.
(e)CortisoneAdrenal cortexInfluence carbohydrate, fat and protein metabolism. Regulate the salt and water balance in the body.

Long Answer Questions

Question 5

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

Answer

Exocrine GlandEndocrine Gland
The exocrine gland sends their secretions (enzymes) through ducts directly to target organs.Endocrine glands are ductless glands that pour their secretions (hormones) directly into the blood.
Ex. Salivary gland, Pancreas, etc.Ex.Thyroid, Pituitary, etc.

Question 6

Why is Pituitary gland called the "master gland"?

Answer

Pituitary gland secretes some hormones that regulate the activity of other endocrine glands. So, the pituitary gland is also called the "master gland".

Question 7

Briefly write about the importance of physical hygiene during adolescence.

Answer

Physical hygiene plays a very important role in maintaining one's own health during adolescence. Following are some important practices for maintaining physical hygiene:

  1. Proper and safe food:
    1. To support rapid growth and development during adolescence, an adolescent should take a balanced diet including proteins, carbohydrates, fats, minerals, and vitamins. Milk, fruits and fresh vegetables should be part of the regular diet.
    2. Avoid stale food and excessive fast food.
    3. Perishable food items should be properly stored in refrigerator.
  2. Proper lifestyle:
    1. Avoid long hours of continuous table work.
    2. Avoid watching television and playing computer games for long hours.
    3. Avoid smoking and consumption of alcohol and drugs.
  3. Cleanliness:
    1. Washing hands with soap before and after meals, brushing teeth, taking regular bath, regular toilet habits should be followed.
    2. Clothes, especially undergarments should be changed daily. Wearing very tight clothes should be avoided.
    3. Eyes should be washed daily with clean and cold water. Rubbing of eyes with hands should be avoided to prevent entry of germs.
    4. Lack of cleanliness may lead to bacterial infection. Girls should take special care of cleanliness during the time of their menstrual cycle.
  4. Physical Exercise:
    1. All young boys and girls should walk, exercise and play outdoor games regularly.
    2. Physical activity is important to combat the stress and strain of adolescence.

Question 8

Briefly discuss any four activities which can be practiced to overcome stress.

Answer

Four activities which can be practiced to overcome stress are:

  1. Yoga — Yoga is a mind body practice that combines physical poses, controlled breathing and meditation or relaxation. It helps to reduce stress with:
    1. Increased flexibility.
    2. Increased muscle strength and tone.
    3. Improved respiration, energy and vitality.
    4. Weight reduction.
    5. Improved athletic performance.
  2. Exercise — Just 30 to 45 minutes of exercise at least three times a week can make one feel much healthier. Regular exercise can be done by running/jogging, swimming, cricket, football, hockey, etc.
  3. Proper sleep schedule — Sound and timely sleep helps one to reduce the level of stress.
  4. Reading — It is a great way to calm the mind and to gain knowledge.
PrevNext