Science In Everyday Life Solutions for Class 8 Science Chapter 8 Age Of Adolescence are provided here with simple step-by-step explanations. These solutions for Age Of Adolescence are extremely popular among class 8 students for Science Age Of Adolescence Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Science In Everyday Life Book of class 8 Science Chapter 8 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Science In Everyday Life Solutions. All Science In Everyday Life Solutions for class 8 Science are prepared by experts and are 100% accurate.

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Question 1:

What are hormones? Name two endocrine glands and the hormones secreted by them.

Answer:

Hormones are chemical substances released by endocrine glands and travel in our body as messengers.
Two endocrine glands and their hormones are as follows:
(i) Pituitary gland secretes thyroid stimulating hormone and growth hormone.
(ii) Thyroid gland secretes thyroxine.

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Question 2:

What effects are caused due to release of hormones inside the body?

Answer:

When hormones are released in the body, they travel in our body and act as messengers. They can signal increased or decreased activity of various organs, muscles etc.

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Question 3:

List some of the changes brought about by adrenaline.

Answer:

 Adrenaline can cause changes like increase in heartbeat, increase in blood sugar level and results in overall increase in body’s energy level.

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Question 4:

What do you understand by adolescence? At what age is it reached?

Answer:

Adolescence is the period of transition from childhood to adulthood. It is reached at the age of 10 years and lasts up to 19 years of age. 

Page No 122:

Question 1:

Write one word for the following.

1. Bag-like structures located at specific places that release chemicls ....................
2. Chemical substances that act like chemical messengers ....................
3. Transition period from childhood to adulthood ....................
4. Process of release of an ovum from an ovary ....................
5. Cycle of producing and releasing mature ova ....................

Answer:

  1. Glands
  2. Hormones
  3. Adolescence
  4. Ovulation
  5. Menstrual cycle

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Question 2:

Write two examples for each of the following.

1. Endocrine glands .................... ....................
2. Hormones .................... ....................
3. Reproductive hormones .................... ....................
4. Secondary sexual characteristics in males .................... ....................
5. Secondary sexual characteristics in females .................... ....................

Answer:

  1. Pituitary gland, thyroid gland
  2. Thyroid stimulating hormone, insulin
  3. Oestrogen, testosterone
  4. Facial hair, Enlarged muscles
  5. Developed of breasts, menstrual cycle

Page No 122:

Question 1:

Which of these is called the master gland?
(a) Pituitary
(b) Thyroid
(c) Adrenal
(d) Pancreas

Answer:

(a) Pituitary.
 Pituitary gland controls, activities of other endocrine glands, thus it is called as master gland.

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Question 2:

Which of these is called the gland of emergency?
(a) Pituitary
(b) Thyroid
(c) Adrenal
(d) Pancreas

Answer:

(c) Adrenal.
Adrenal gland helps the body to react in emergency situations.

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Question 3:

Which of these is a male sex hormone?
(a) Oestrogen
(b) Testosterone
(c) Thyroxine
(d) Progesterone

Answer:

(b) Testosterone.
Testosterone is a male hormone that controls secondary sexual characteristics in males.

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Question 4:

Menstruating girls need to have foods richer in
(a) iron
(b) fats
(c) carbohydrates
(d) vitamins

Answer:

(a) Iron.
Menstruating girls need to consume food rich in iron as blood loss occurs during menstruation.

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Question 5:

Which of these is a drug?
(a) Cocaine
(b) Marijuana
(c) Nicotine
(d) All of these

Answer:

(d) All of these.
Cocaine, marijuana and nicotine are examples of narcotic drugs.

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Question 1:

Match the following.

Column A Column B
Pituitary gland Oestrogen
Thyroid gland Insulin
Pancreas Testosterone
Ovaries Thyroxine
Testes Master gland

Answer:

Pituitary gland Master gland
Thyroid gland Thyroxine
Pancreas   Insulin
Ovaries Oestrogen
Testes Testosterone



Page No 123:

Question 5:

What does puberty refer to?

Answer:

Puberty refers to the stage of life when the body starts becoming sexually mature.

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Question 6:

Why do adolescents experience mood swings?

Answer:

During adolescence, emotional changes and fluctuations in hormone level can cause mood swings to occur.

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Question 7:

Why is it important to eat healthy foodstuffs during adolescence?

Answer:

There is rapid physical and mental growth occurring during adolescent period, which increases the nutritional demand of the body. Therefore, it is important to eat healthy foodstuff during adolescence. 

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Question 8:

Why is it important to maintain personal hygiene during puberty?

Answer:

Personal hygiene should be maintained during puberty as there may be increased sweating that can cause increased growth of bacteria causing bad odour.  Genital areas need to be kept clean, especially during menstruation and face should be washed with mild soap to protect it from acne.

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Question 9:

What are the common symptoms of drug abuse?

Answer:

Drug abuse shows common symptoms like physical, mental, behavioural and emotional changes and developing a dependence on them called addiction. This makes it difficult to stop taking drugs.

Page No 123:

Question 1:

Describe the location and hormone secreted by any five endocrine glands in our body.

Answer:

The location and hormones secreted by five endocrine glands in human body are

  • Pituitary gland, called master gland is located at the base of brain and secretes thyroid stimulating hormone (TSH) and growth hormone (GH).
  • Thyroid gland is located at the base of throat and secretes thyroxine hormone.
  • Adrenal gland responds during emergency and is called the gland of emergency. It is located near the kidneys and secretes adrenaline.
  • Pancreas is located near the liver and secretes insulin.
  • Testes are the male genital organs and secrete testosterone.

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Question 2:

Describe the role of any five hormones in our body.

Answer:

The role of five hormones in human body are as follows:

  • Growth hormone stimulates the growth and development of the body.
  • Insulin regulates blood sugar level, inability of which can cause diabetes.
  • Adrenaline helps the body to defend during emergency situations.
  • Oestrogen controls development of secondary sexual features in females such as development of breasts.
  • Testosterone controls development of secondary sexual features in males like facial hair. 

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Question 3:

Explain some physical changes that boys and girls experience during puberty.

Answer:

Following physical changes are experienced by boys and girls during puberty:

(a) There is a sudden increase in the height of the boys and girls when he/she reaches the puberty.
(b) There is a change in the shape of the body. In girls, the pelvic region gets widen. In boys, the shoulders get broaden.
(c) There is a change in voice due to increase due to the growth of larynx. Girls voice gets high pitched whereas the voice of boys becomes deep.
(d) The activity of sweat and sebaceous glands also increase which cause acne and pimples in some boys and girls.
(e) Sex organs develop in both boys and girls.
(f) Male and human sex hormones start secreting. Testosterone is the male sex hormone and oestrogen is female sex hormone.

 

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Question 4:

What is menstrual cycle? Explain the changes that occur during the menstrual cycle in an adolescent girl.

Answer:


Menstrual cycle is the process of forming and releasing ova and it starts during adolescence. The uterus prepares for pregnancy and under the influence of hormones, oestrogen and progesterone, the ovary releases a mature ovum during ovulation by around 14th day of the menstrual cycle. When the ovum is not fertilized by a male sperm, it is thrown out of the body along with outer lining of uterus and hormone levels drops. Menstruation occurs when the uterus wall lining starts breaking down and sheds, causing blood loss, which lasts for 4 to 6 days.

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Question 5:

Discuss the role of hormones during puberty.

Answer:

Hormones are responsible for the changes occurring during adolescence. A hormone released by pituitary gland stimulates ovaries in girls to produce female sex hormones, oestrogen and progesterone. Oestrogen controls ova production and development of secondary sexual characters in girls. In boys, a hormone secreted by pituitary gland stimulates the production of male sex hormone testosterone from the testes. Testosterone controls sperm cell production and development of secondary sexual characters in boys.

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Question 6:

Write a short note on drug abuse and AIDS.

Answer:

Drug abuse:
The chemical substances that produce physical, mental, emotional or behavioral changes are called drugs, e.g. alcohol, cocaine, marijuana, nicotine in cigarettes or gutka. Using these for purposes other than medicinal usages is called drug abuse. It harms the body and the user develops physical and psychological dependence on the drugs, called addiction.

AIDS:
AIDS (Acquire Immunodeficiency syndrome) is a disease which is caused by the infection of HIV virus.
AIDS is caused by the following modes:
(a) Unprotected sexual contact with the infected person.
(b) Transfusion of blood contaminated by HIV.
(c) Use of unsterilised needles for injections.
It can be prevented by following two ways:
(a) Avoiding sexual contact with an unknown person.
(b) Using sterilised needles for injections.



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