Frank Cce Everyday Science Solutions for Class 8 Science Chapter 10 Adolescence, Puberty And Hormones are provided here with simple step-by-step explanations. These solutions for Adolescence, Puberty And Hormones are extremely popular among class 8 students for Science Adolescence, Puberty And Hormones Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Frank Cce Everyday Science Book of class 8 Science Chapter 10 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Frank Cce Everyday Science Solutions. All Frank Cce Everyday Science Solutions for class 8 Science are prepared by experts and are 100% accurate.

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1 – INSULIN
2 (Across) – TESTOSTERONE
2 (Down) – THYROXINE
3 – PUBERTY
4 – MENARCHE



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(c) 14−15 years
Sexual maturity in males is obtained between 14−15 years of age.

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(d) embryo
Embryo is not a part of the female reproductive system.

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(a) Testis
Sperms are produced in the testes of males.

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(b) hormones
Secretions of endocrine glands are called hormones.

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(a) Pituitary
Pituitary gland is also called the master gland because it controls the secretions of the other endocrine glands in the body.

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(a) faster
Initially, girls grow faster than boys.

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(a) adolescent boy
Moustache, beard, wider shoulder and deeper voice are the secondary sexual characteristics of an adolescent boy.

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(b) XY
The XY pair of chromosomes is capable of determining the sex of a child.

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(a) menarche
The onset of menstrual flow in females is known as menarche.

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(d) growth
Growth is controlled by hormones.

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1. Insulin maintains the level of sugar in the blood.
2. Increased activity of sebaceous glands causes pimples in both boys and girls at puberty.
3. Thyroid gland produces thyroxine hormone.
4. Testes produces the male sex hormone testosterone.
5. Adrenalin is also called the emergency hormone.
6. AIDS is caused by the HIV virus.

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Column A Column B
1. Estrogen  (e) Female sex hormone
2. XY chromosome  (d) Male child
3. Insulin  (c) Diabetes
4. Adam's apple  (b) Puberty
5. Testosterone (a) Male sex hormone



Page No 151:

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A woman has to bear child in her womb. But, at old age, she becomes weak and if she remains fertile till then, she may become pregnant, which would cause harm to her life. Hence, the reproductive age of a woman starts from menarche and ends at menopause. 

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It is said that the father is responsible for the determination of the sex of the unborn child because males have XY pair of sex chromosomes, whereas females have XX pair of sex chromosomes. Gametes have only one member of this pair. Ovum has X chromosome, while sperm cell has either X or Y chromosome. When the gametes fuse, these single members (X or Y) unite to form a new pair of chromosomes that determines the sex of the baby. For example, the X chromosome of the ovum unites with the X chromosome of the sperm cell. The resulting zygote has XX pair of chromosomes, which is a female.

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During adolescence, children go through many mental and emotional changes. They start thinking more maturely and become more independent than before. They tend to spend a lot of time thinking. Sometimes, they face difficulty in adjusting to the changes that occur in their mind and body. As a result, they often find themselves feeling insecure in their adolescent age.

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We specially emphasise that adolescents should avoid drugs because they go through many mental and emotional changes during adolescence. They may start consuming drugs in order to overcome negative emotions (such as stress, pressure, depression and frustration) and to excel in various fields. Sometimes, curiosity, need for adventure and excitement, and experimentation also make them consume drugs. 
Since drugs have an inherent additive nature, once the adolescent starts taking them, he/she gets dependent on it. This can lead to a number of problems including health concerns and criminal charges.

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No, there is no chance of contracting AIDS by sharing food with a person suffering from this disease. AIDS does not spread by touching an infected person or by sitting with him or her. It spreads by transfer of body fluids such as blood during blood transfusion or semen during unprotected sex with an infected person.

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1. (F) False. The father is responsible for the sex of the baby.
2. (T) True. Estrogen is the female sex hormone.
3. (T) True. Pituitary gland is also called the master gland.
4. (T) True. Diabetes is caused by the deficiency of insulin in the blood.
5. (T) True. Menstrual cycle starts in a girl at puberty.

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Adolescence is the period of transition of a child into an adult.

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Puberty is the stage of life when the body starts becoming sexually mature. Girls attain puberty earlier than boys.

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Chemical substances called hormones are secreted by endocrine glands.

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The other name for ductless glands is endocrine glands.

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Menarche     Menopause
It is the first menstrual flow that marks the beginning of the reproductive life in females. It is the last menstrual flow that marks the end of the reproductive life in females.
It starts at the age of 11 or 12.  It occurs between the ages of 45 to 50 years.

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There are 46 chromosomes or 23 pairs of chromosomes in the nuclei of the human cell.

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Adam's apple refers to the protruding voice box seen in the throat of adolescent boys. This happens due to increase in the size of the larynx.

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Testosterone is the male sex hormone.

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Oestrogen is the female sex hormone secreted by the ovaries.

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AIDS (Acquired Immuno-Deficiency Syndrome) is a disease caused by the infection of HIV virus.

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Some adolescents get pimples on their faces due to increased secretion of sebum (oil) from the sebaceous gland. Sebum makes the skin oilier and leads to the appearance of pimples.

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Adam's apple refers to the protruding voice box seen in the throat in adolescent boys. This happens due to an increase in the size of the larynx.

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The pituitary gland is called the master gland because it influences or controls the functioning of the other glands. It releases the growth hormone (GH) that controls the development in the body. It also releases the thyroid stimulating hormone (TSH) that stimulates the thyroid gland to secrete thyroxine.

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AIDS (Acquired Immuno-Deficiency Syndrome) is a disease caused by the infection of HIV virus.
It can be prevented by the following two ways:
(a) Avoiding sexual contact with an unknown person
(b) Using sterilised needles for injections

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The ovum remains available for fertilisation only for a single day. When fertilisation does not take place, the ovum and the thickened lining of the uterus are shed off along with the blood vessels. This leads to the process of bleeding in women, which is known as menstruation.



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Hormones are chemical substances that are secreted by the ductless glands or endocrine glands and released directly into the blood stream. They are responsible for regulating growth, development, behaviour and reproduction.

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Endocrine system refers to a group of endocrine or ductless glands that secrete different hormones in the body. Pituitary gland, thyroid gland, pancreas, adrenal gland, ovaries and testes are included in the endocrine system.

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Dwarfism is caused by the decreased secretion of the growth hormone by the pituitary gland. The growth hormone is responsible for the development of bones and muscles. If it is not secreted in adequate amounts, then the person remains very short in stature and suffers from dwarfism.

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Insulin is secreted by the pancreas. Its main function is to regulate the amount of glucose in the blood. Deficiency of insulin in a person causes diabetes.

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Metamorphosis is a biological process of transforming larva into an adult. The process involves relatively abrupt changes in the animal's structure through cell growth and development. Frog and silkworm are examples of animals that develop through metamorphosis.

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The following changes occur in a child's body during puberty:
(a) There is a sudden increase in the height of the child when he/she reaches puberty.
(b) There is a change in the shape of the body. In girls, the pelvic region gets widened. In boys, the shoulders get broadened.
(c) There is a change in voice due to the growth of larynx. The voice in a girl gets high-pitched, whereas the voice of a boy becomes deep.
(d) The activity of sweat and sebaceous glands also increases, which causes acne and pimples in some boys and girls.
(e) The sex organs develop in both boys and girls.
(f) The ale and female sex hormones start getting secreted. Testosterone is the male sex hormone and oestrogen is the female sex hormone.

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Blood and mucus flow out every month through the vagina due to the rupture of the lining of uterus if fertilisation does not occur. This process is called menstruation.
The cycle of producing and releasing mature eggs or ova is called the menstrual cycle. The end of each cycle is accompanied by the breakdown of the lining of the uterus that gets released in the form of blood and mucus through the vagina. It takes around 28−30 days for the cycle to complete.
The menstrual cycle starts at the age of 10–15 years (menarche) and stops at the age of 40–50 years (menopause).

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The following changes take place in the body of a female during the menstrual cycle:


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 the hormones oestrogen and progesterone, the ovary releases a mature ovum during ovulation at around the 14th day of the menstrual cycle. When the ovum is not fertilised by a male sperm, it is thrown out of the body along with the outer lining of the uterus and the hormone levels drops. Menstruation occurs when the wall lining of the uterus starts breaking down and is shed causing blood loss that lasts for 4 to 6 days.

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The sex of a baby is determined by the type of sperm that fertilises the ovum.
(i) If a sperm carrying X chromosome fertilises the egg, it would be a baby girl because the chromosome pair would be XX.
(ii) If a sperm carrying Y chromosome fertilises the egg, it would be a baby boy because the chromosome pair would be XY.

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The father is responsible for the sex of a baby because it is determined by the type of sperm that fertilises the ovum. If a sperm carrying X chromosome fertilises the egg, it would be a baby girl because the chromosome pair would be XX. If a sperm carrying Y chromosome fertilises the egg, it would be a baby boy because the chromosome pair would be XY.

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The following changes appear in a girl at puberty:
(a) Enlargement of the breasts
(b) Growth of hair in pubic region and armpits
(c) Widening of the pelvic girdle
(d) Deposition of fat around the hips
(e) Beginning of menstrual cycle

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Secondary sexual characters are physical changes that occur at puberty in males and females.

The following are the secondary sexual characters in human males:
(a) Growth of hair on the face, the pubic region and the armpits
(b) Deepening of the voice
(c) Enlargement of the penis and the scrotum
(d) Development of muscles

The following are the secondary sexual characters in human females:
(a) Enlargement of the breasts
(b) Growth of hair in the pubic region and the armpits
(c) Widening of the pelvic girdle

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Chromosomes carry information in the form of genes and are responsible for determining the sex. Female cells have XX pair of sex chromosomes, while male cells have XY pair of sex chromosomes. Gametes have only one member of this pair. Ovum has X chromosome, while sperm cell has either X or Y chromosome. When a gamete fuses, these single members (X or Y) also unite to form a new pair of chromosomes that determines the sex of the baby. For example, the X chromosome of the ovum unites with the X chromosome of the sperm cell. The resulting zygote has XX pair of chromosomes, which is determined as a female.

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AIDS is caused in the following ways:
(i) Unprotected sexual contact with an infected person
(ii) Transfusion of blood contaminated by HIV
(iii) Use of unsterilised needles for injections
(iv) From an infected mother to her child during pregnancy



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