Solution of Chapter 10. Reaching the Age Adolescence (Lakhmir Singh & Manjit Kaur - Science Book)

What is the special name of the period of life between childhood and adulthood?

Name another term for ‘adolescents’.

State the age at which adolescence usually begins and the age up to which it lasts.

Which is the most conspicuous change (clear visible change) in boys and girls during puberty?

How does the height of boys and girls change during puberty?

Name one factor on which the height of a person depends.

A nine year old boy is 120 cm tall. If the present height of boy is 75% of his full height, calculate the full height which the boy will eventually reach at the end of growth period.

How do shoulders and chest change in boys during puberty?

How do hips of girls change during puberty?

What is the other name of ‘voice box’?

Which of the two have a smaller voice box: grown up boys or grown up girls?

What is the common name of the bulge (or projection) at the front of throat in grown up boys?

What substance is secreted by sebaceous glands?

Name the time period in one’s life when the brain has the greatest capacity for learning.

Name two glands present in the skin whose increased activity causes pimples and acne.

What name is given to those sexual characteristic in humans:

(a) which are present in babies at birth?

(b) which develop in mature boys and girls?

Name any two glands which function as endocrine glands as well as exocrine glands.

What is the other name of ductless glands?

What term is used for the secretion of endocrine glands?

Name:

(a) female sex hormone, and

(b) male sex hormone.

Name the hormone which develops secondary sexual characteristic:

(a) in females (girls).

(b) in males (boys)

State the function of male sex hormone ‘testerone’.

Name the endocrine gland which controls the production of sex hormones ‘testosterone’ and ‘estrogen’.

What is the name of the process in which the thickened uterus lining along with its blood vessels is removed from the body of a woman through vaginal bleeding?

Which comes earlier in the life of a woman: menarche or menopause?

Around which age menarche occurs in girls ?

Around which age menopause occurs in woman?

State one situation (other than menopause) when ovulation and menstruation stop in a woman.

Which of the two has a shorter reproductive phase of life: men or women?

Which of the following combinations of sex chromosomes products a male child (or boy)?

XX or XY

Which of the two, sperm or egg cell (ovum), decides the sex of the child?

What is the legal age for the marriage of (a) boys, and (b) girls, in our country?

Name a natural balanced food for infants.

During which time the adolescent girls should take special care of personal hygiene?

Write the full name of (i) AIDS, and (ii) HIV.

Write the name of the virus which causes AIDS disease.

Name the endocrine gland attached to the base of brain.

Name the endocrine gland which secrets the growth hormone.

Name the substance which is needed continuously by thyroid gland to make thyroxine hormone.

State the main symptom of goiter.

Name the hormone whose deficiency in body causes goiter.

Name the gland which secretes insulin hormone.

Name the disease caused by the insufficient production of insulin hormone by pancreas.

Name the hormone which prepares our body for action to face emergency situation like danger, fear, anger or excitement.

Name the endocrine gland which secretes hormone that maintains correct salt balance in the blood.

Name a hormone (other than adrenalin) secreted by adrenals.

Name the hormone whose deficiency causes diabetes.

Name the hormone which is required for the metamorphosis of larvae (tadpoles) into adult frogs.

Name the hormone which brings about metamorphosis in silk moth and changes caterpillar (larva) into adult silk moth.

State whether the following statements are true or false:

(a) The estrogen hormone develops deeper voice in males at puberty.

(b) Menstruation stops in men permanently around the age of 45 to 50 years.

(c) Man (father) is responsible for the sex of the body.

(d) The sex chromosomes in all the gametes (sperms) of a man are not identical.

(e) Half the female gametes contain X chromosomes and the other half contain Y chromosomes.

(f) It is the sperm which determines the sex of a child.

(g) Each normal cell in our body contains 23 chromosomes and the other half contain Y chromosomes.

(h) A girl should not be allowed to work in the kitchen during menstruation.

(i) A woman (mother) is responsible for the sex of her child.

(j) Metamorphosis in insects (like silk moth) is brought about by thyroxine hormone.

Fill in the following blanks with suitable words:

(a) Sexual maturity is reached at……………

(b) The changes which occur in boys and girls at puberty are brought about by various………….

(c) Initially, girls grow…..than boys.

(d) The changes occurring in body and mind during adolescence are a natural part of……………….up.

(e) The features which help us to distinguish between a mature boy and a girl are called………sexual characteristics.

(f) The onset of puberty is controlled by…………..

(g) Menstrual cycle in women is controlled by…………….

(h) Each normal body cell in humans contains……………..pairs of chromosomes out of which……………..pair is of sex chromosomes.

(i) X and Y chromosomes are called……….chromosomes.

(j) Early marriage and motherhood cause health problems in the ……………and the……………….

(k) The protective foods are ………. And ……………….

(l) Thyroid and adrenals secrete their hormones when they receive instructions from……..gland through its hormones.

(m) Metamorphosis in amphibians is brought about by…….hormone.

Define adolescence. State some of the change which take place in boys and girls during adolescence.

What is puberty? Who attains puberty at an earlier age in human beings: male (boy) or female (girl).

Write two changes that happen during puberty to: (a) both boys and girls (b) boys only (c) girls only.

State two ways in which the body shape of boys changes during puberty.

State two ways in which the body shape of girls changes during puberty.

State one change in the body shape of grown up boys and one changes in the body shape of grown up girls which makes them look different.

What is the effect of a larger voice box in grown up boys?

What is the effect of a smaller voice box in grown up girls?

What is Adam’s Apple? Which of the two usually have an Adam’s Apple: grown up boys or grown up girls?

What change in the voice of body takes place when they reach puberty? What is the cause of this change?

Name two male sex organs and two female sex organs which develop completely at puberty.

Name two things which may develop on the face of adolescent boy s and girls during puberty due to the increased activity of sebaceous glands and sweat glands in the skin.

State two secondary sexual characteristics in mature boys and two in mature girls.

Which of the following are secondary sexual characteristics?

Ovaries, Moustache, Penis, Broad hips, Vagina, Beard, Breast, Adam’s Apple, Wide shoulders, uterus, Testes, Deeper voice.

Which of the following are endocrine glands?

Salivary gland, Thyroid gland, Adrenal gland, Sweat gland, Pituitary gland, Sebaceous gland (Oil gland)

What name is given to the onset of menstruation in human females (or girls)? At what age does this occur?

What name is given to the permanent stoppage of menstruation in women? At what age does this occur?

Who is responsible for the sex of the unborn child: father or mother? Why?

What will be the sex of the child born:

(a) if X chromosome carrying sperm fuses with an egg cell carrying X chromosome?

(b) if Y chromosome carrying sperm fertilizes an ovum containing X chromosome?

What are hormones? Where are hormones made in the human body?

What are sex hormones? Name two sex hormones.

Define (i) menarche, and (ii) menopause.

What is menstruation? Explain.

What are sex chromosomes? Name the two types of sex chromosomes.

Explain how sex is determined in the unborn baby.

What are the various ways in which AIDS virus (HIV) can be transmitted?

Explain how, the use of drugs helps in spreading AIDS disease.

State the harmful effects of taking drugs.

Name one hormone secreted by pituitary gland. State the function of this hormone.

Explain why, people are advised to use iodized salt in cooking food.

What is goiter? What causes goiter?

Which hormone lowers the blood sugar in humans? Name the gland which secretes this hormone.

Name the hormone secreted by pancreas. What is the function of this hormone?

What is the function of adrenaline hormone in the body?

Name six endocrine glands in the human body. Also name the hormones secreted by each one of these glands.

Where are the following glands located in the human body?

(i) Pituitary

(ii) Thyroid

(iii) Pancreas

(iv) Adrenals

What will happen if the water in which tadpoles are growing does not contain sufficient iodine?

What is acne?

What are pimples? How are pimples formed?

Name two food items each which provide mainly:

(a) carbohydrates for energy

(b) fats for energy

(c) Proteins for growth

(d) vitamins and minerals for good health

Why is iron mineral needed by our body? Name some of the iron-rich foods.

State any two practices which can be adopted by adolescents to maintain personal hygiene.

Why is the more necessary for adolescents to take bath regularly (at least once everyday)?

What will happen if personal hygiene (Cleanliness of body) is not maintained by adolescents?

State the various ways in which early marriage and motherhood is harmful to the girls.

What changes take place in boys during puberty?

What changes take place in girls during puberty?

What is meant by the ‘primary sexual characteristics’ in humans? State two primary sexual characteristics in boys and two in girls.

What is meant by ‘secondary sexual characteristics’ in humans? Explain with the help of two examples.

Describe menstrual cycle. What is the duration of menstruation cycle in women?

What is an exocrine gland? Name two exocrine glands.

What is an endocrine gland? Name two endocrine glands.

What is meant by ‘reproductive health’?

State the conditions necessary to maintain good reproductive health during adolescence.

Reproductive age in women starts when their:

The sex of a child is determined by:

The legal age for the marriage of boys in our country is:

The legal age for the marriage of girls in our country is:

The right meal for adolescents consists of:

Adolescents should be careful about what they eat because Adolescents should be careful about what they eat because:

AIDS disease is caused by:

Which of the following human disease can be prevented by the same hormone which brings about metamorphosis in frogs?

Which of the following is a mis-matched pair?

The hormone which is associated with male puberty is called:

The dramatic changes in body features associated with puberty are mainly because of the secretions of:

A) Thyroxine

B) Estrogen

C) Adrenaline

D) Testosterone

Which of the following endocrine gland does not occur as a pair in the human body?

Iodine is necessary for the synthesis of one of the following hormones. This hormone is:

Which of the following endocrine gland does not a primary sexual characteristic in females?

Which of the following is the secondary sexual characteristics in females?

Which of the following can lead to menstruation in a 21 year old woman during ovulation?

A) Sperms available for fertilization

B) Oviducts blocked

C) Sperms not available for fertilization

D) Oviducts not blocked

The faulty functioning of an endocrine gland can make a person very short or very tall. This gland is:

Which of the following hormone prepares our body for action in emergency situations?

A doctor advised a person to take injection of insulin because:

Pimples and acne are formed due to the increased activity of:

A) Adrenal glands

B) Sebaceous glands

C) Thyroid gland

D) Sweat glands

When a human female reaches a certain age, then vaginal bleeding occurs for a few days after rehular intervals of time:

(a) what is this process known as (i) in scientific terms, and (ii) in everyday language?

(b) What is the human female said to have attained at this stage?

(c) What does the onset of this process in human female signify?

(d) At what particular event in the life of a human female this process stops temporarily but starts again?

(e) What name is given to the event when this process stops permanently?

A woman is in her reproductive phase of life. Even when the sperms are available at the time of release of a mature ovum by her ovary, fertilization does not take place. Due to this, the woman is unable to bear a baby.

(a) What is the most likely defect in the reproductive system of this woman?

(b) Name the technique by which this woman can also have a baby?

Raj Kumar and his wife Sunita have been blessed with a baby girl. On the other hand, Kripa Shanker and his wife Vimla have been blessed with a baby boy. What type of sex chromosome has been contributed:

(a) by raj Kumar

(b) by Sunita

(c) by Kirpa Shanker

(d) by Vimla

A gland W is located just below the stomach in the human body. The gland W secrets a hormone X. The deficiency of hormone X in the body causes a disease Y in which the blood sugar level of a person rises too much. The person having high blood sugar is called Z. What are W, X, Y and Z?

It was observed that the tadpoles are not growing into adult frogs in a village pond. A scientist who was asked to find the reason for this concluded that the pond water did not contain sufficient amount of a mineral P which could make a hormone Q. The hormone Q can causes a phenomenon R in tadpoles so that they become adult frogs.

(a) What are (i) P (ii) Q, and (ii) R?

(b) name one human disease which can also be caused due to the deficiency of P in the food and water.