Endocrine System and Adolescence
Solutions for Biology, Class 8, ICSE
Assertion Reason Type Questions
5 questionsAssertion (A): The exocrine glands send their secretions (enzymes) to the target organs through ducts.
Reason (R): Such glands are called exocrine glands because their secretions act on the surface of organs.
- Both A and R are true.
- Both A and R are false.
- A is true and R is false.
- A is false and R is true.
Answer:
Both A and R are true.
Explanation — Exocrine glands send their secretions (enzymes) to the target organs through ducts. These secretions usually act on the surface of organs, such as the skin or digestive tract.
Assertion (A): Endocrine glands pour their secretions directly into the blood in very large quantities.
Reason (R): Hormones are utilized in very large quantities continuously throughout the body as these secretions regulate the growth and development as well as many other metabolic activities of the body.
- Both A and R are true.
- Both A and R are false.
- A is true and R is false.
- A is false and R is true.
Answer:
Both A and R are false.
Explanation — The endocrine glands have no ducts and they pour their secretions (hormones) directly into the blood. The secretions of these glands or hormones are secreted in very small quantities, and are carried to all parts of the body.
Assertion (A): Thyroxine is the hormone which regulates basal metabolism of the body and speeds up the rate of most activities of the body.
Reason (R): Its undersecretion is harmful which can cause different types of ailments but its oversecretion is very important as it increases the metobolic rate of the body.
- Both A and R are true.
- Both A and R are false.
- A is true and R is false.
- A is false and R is true.
Answer:
A is true and R is false.
Explanation — Thyroxine is an iodine-containing hormone and is very important for our body. However, its oversecretion is harmful too as it can cause an increase in metabolic rate and heartbeat, weight loss, restlessness, and other issues.
Assertion (A): The hormone epinephrine is secreted by the Adrenal cortex when a person is under stress (physical or emotional), fearful or angry.
Reason (R): This hormone prepares the body to meet any emergency situation, i.e. to face the danger or flee from a situation.
- Both A and R are true.
- Both A and R are false.
- A is true and R is false.
- A is false and R is true.
Answer:
A is false and R is true.
Explanation — Adrenal Medulla secretes adrenaline or epinephrine hormone, when a person is under severe stress (physical or emotional), fearful or angry. This hormone provides extra energy and strength to the body in any adverse (or emergency) situation.
Answer:
Both A and R are false.
Explanation — Insulin promotes the conversion of extra glucose to glycogen which is ultimately stored in the liver and muscles. Hence, insufficient secretion of insulin leads to an increase in the concentration of sugar (glucose) in the blood causing diabetes mellitus.
Long Answer Questions
10 questionsAnswer:
Difference between Exocrine and Endocrine glands on the basis of secretion:
Characteristic | Exocrine glands | Endocrine glands |
---|---|---|
Secretion | Exocrine glands secrete their products like sweat, enzyme, mucus, sebum, saliva, milk, etc. into ducts. | Endocrine glands secrete their products, known as hormones, directly into the bloodstream. |
Answer:
Difference between Cretinism and Myxoedema on the basis of symptoms:
Characteristic | Cretinism | Myxoedema |
---|---|---|
Symptoms | Cretinism occurs in infants resulting in physical and mental retardation. | Myxoedema occurs in adults and is characterised by symptoms such as sluggishness with swelling on face and hands. |
Answer:
Difference between Insulin and Glucagon on the basis of function:
Characteristic | Insulin | Glucagon |
---|---|---|
Function | Insulin lowers blood glucose levels by facilitating the uptake of glucose into cells and its conversion to glycogen in the liver and muscles. | Glucagon raises blood glucose levels by promoting the conversion of glycogen back to glucose in the liver and muscles. |
Answer:
Difference between Thyroxine and Adrenaline on the basis of source:
Characteristic | Thyroxine | Adrenaline |
---|---|---|
Source | Thyroxine is produced by the thyroid gland. | Adrenaline is produced by the adrenal glands. |
Answer:
Difference between Human male and female hormone on the basis of one example of each:
Characteristic | Human male hormone | Human female hormone |
---|---|---|
One example | A common male hormone is testosterone. | An example of a female hormone is estrogen. |
Answer:
Epinephrine (also called adrenaline) is released by the adrenal glands in response to stress. This hormone prepares the body to meet any emergency situation i.e., to face the danger or flee from a situation. Hence it is called the 'fight or flight hormone' or the 'emergency hormone'.
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:
- Proper and safe food:
- 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.
- Avoid stale food and excessive fast food.
- Perishable food items should be properly stored in refrigerator.
- Proper lifestyle:
- Avoid long hours of continuous table work.
- Avoid watching television and playing computer games for long hours.
- Avoid smoking and consumption of alcohol and drugs.
- Cleanliness:
- Washing hands with soap before and after meals, brushing teeth, taking regular bath, regular toilet habits should be followed.
- Clothes, especially undergarments should be changed daily. Wearing very tight clothes should be avoided.
- Eyes should be washed daily with clean and cold water. Rubbing of eyes with hands should be avoided to prevent entry of germs.
- Lack of cleanliness may lead to bacterial infection. Girls should take special care of cleanliness during the time of their menstrual cycle.
- Physical Exercise:
- All young boys and girls should walk, exercise and play outdoor games regularly.
- Physical activity is important to combat the stress and strain of adolescence.
Answer:
Four activities which can be practiced to overcome stress are:
- Yoga — Yoga is a mind body practice that combines physical poses, controlled breathing and meditation or relaxation. It helps to reduce stress with:
- Increased flexibility.
- Increased muscle strength and tone.
- Improved respiration, energy and vitality.
- Weight reduction.
- Improved athletic performance.
- 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.
- Proper sleep schedule — Sound and timely sleep helps one to reduce the level of stress.
- Reading — It is a great way to calm the mind and to gain knowledge.
Match The Following
1 questionMatch the items in Column A with those in Column B.
Column A | Column B |
---|---|
Cretinism | Pituitary Gland |
Diabetes Mellitus | Abnormal development of infant |
Increased metabolic rate | Oversecretion of thyroxine |
Simple goitre | Insufficient iodine in food |
Growth hormone | Insufficient insulin in blood |
Answer:
Column A | Column B |
---|---|
Cretinism | Abnormal development of infant |
Diabetes Mellitus | Insufficient insulin in blood |
Increased metabolic rate | Oversecretion of thyroxine |
Simple goitre | Insufficient iodine in food |
Growth hormone | Pituitary gland |
Objective Type Questions
10 questionsAnswer:
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).
Answer:
Iodine
Reason — Myxoedema is is a condition seen in an adult when insufficient amount of thyroxine is produced. It shows general sluggishness with swelling on the face and hands, caused due to the deficiency of Iodine.
Pituitary gland is considered as the 'master gland' of the body. Which of the following reasons supports this statement?
P. It is a pea-sized gland.
Q. It is the largest and strongest gland.
R. It regulates the activities of all other endocrine glands.
- Only P and R
- Only Q
- Only R
- Only P and Q
Answer:
Only R
Reason — Pituitary gland is a pea-sized gland, located below the brain. However, it is called the 'master gland' due to the fact that it secretes several hormones, some of which regulate the activity of other endocrine glands.
Aman is in the state of mental or emotional strain which can be termed as 'stress'. In simple terms, people call it 'tension'. Which of the following ways can help Aman manage his stress?
P. Yoga and exercise.
Q. Uncontrolled eating and watching television.
R. Deep breathing and meditation
- Only P and Q
- Only Q and R
- Only Q
- Only P and R
Answer:
Only P and R
Reason — Yoga, exercise, deep breathing and meditation are among the few methods that help manage stress or tension.
Short Answer Questions
9 questionsIn 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 gland | Hormone produced | Function |
---|---|---|---|
1. | Thyroid | ............... | ............... |
2. | ............... | Insulin | ............... |
3. | ............... | ............... | Prepares the body for action |
4. | ............... | Growth Hormone | ............... |
Answer:
S.No | Name of the gland | Hormone produced | Function |
---|---|---|---|
1. | Thyroid | Thyroxine | Control of metabolic rate |
2. | Pancreas | Insulin | Regulation of sugar in blood. |
3. | Adrenal Medulla | Adrenaline | Prepares the body for action |
4. | Pituitary | Growth Hormone | Speeds up growth |
Answer:
(a) Thyroid gland — The thyroid gland is located on either side of the wind pipe, just below the larynx.
(b) Adrenal gland — The adrenal glands are located on top of each kidney like caps.
(c) Pancreas — The pancreas is located behind the stomach.
(d) Pituitary gland — The pituitary gland is located at the base of the brain, below the hypothalamus.
(e) Adam's apple — The Adam's apple is located in the protruding part of the throat.
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 | Breakdown of glycogen to glucose. Raises sugar in the blood. |
(b) | Thyroxine | Thyroid gland | Control of metabolic Rate . |
(c) | Adrenaline | Adrenal Medulla | Prepare the body to face emergency, stress. |
(d) | Insulin | Pancreas | Regulation of sugar in blood. |
(e) | Cortisone | Adrenal cortex | Influence carbohydrate, fat and protein metabolism. Regulate the salt and water balance in the body. |