Case Study Questions Class 8 Science Reaching the age of adolescence

Case Study Questions Class 8 Science Chapter 10 Reaching the age of adolescence

CBSE Class 8 Case Study Questions Science Reaching the age of adolescence. Important Case Study Questions for Class 8 Board Exam Students. Here we have arranged some Important Case Base Questions for students who are searching for Paragraph Based Questions Reaching the age of adolescence.

At Case Study Questions there will given a Paragraph. In where some Important Questions will made on that respective Case Based Study. There will various types of marks will given 1 marks, 2 marks, 3 marks, 4 marks.

CBSE Case Study Questions Class 8 Science Reaching the age of adolescence

Case study 1

Changes at Puberty: Increase in HeightThe most conspicuous change duringpuberty is the sudden increase inheight. At this time the long bones, thatis, the bones of the arms and the legselongate and make a person tall.Initially, girls grow faster than boysbut by about 18 years of age, both reachtheir maximum height. The rate ofgrowth in height varies in differentindividuals. Some may grow suddenlyat puberty and then slow down, whileothers may grow gradually.There is no need for Paheli to worry.All parts of the body do not grow at thesame rate. Sometimes the arms and legsor hands and feet of adolescents lookoversized and out of proportion with thebody. But soon the other parts catchup and result in a proportionate body. You must have noticed that heightof an individual is more or less similarto that of some family member. This isbecause height depends on the genesinherited from parents. It is, however,very important to eat the right kind offood during these growing years. Thishelps the bones, muscles and otherparts of the body get adequate nourishment for growth. You will find nutritional needs of adolescentsdiscussed later in the lesson.Change in Body Shape: Have you noticed that boys in your classhave broader shoulders and wider cheststhan boys in junior classes? This isbecause they have entered the age ofpuberty when shoulders generallybroaden as a result of growth. In girls,the region below the waist becomeswider.In boys, the muscles of the body grow more prominently than in the girls.Thus, changes occurring in adolescent boys and girls are different.Voice Change: Did you notice that sometimes the voiceof some of the boys in your class cracks?At puberty, the voice box or the larynx begins to grow. Boys develop larger voice boxes. The growing voice box in boys canbe seen as a protruding part of the throatcalled Adam’s apple. In girls,the larynx is hardly visible from theoutside because of its small size.Generally, girls have a high-pitched voice, whereas boys have a deep voice. Inadolescent boys, sometimes, the musclesof the growing voice box go out of controland the voice becomes hoarse. This statemay remain for a few days or weeks afterwhich the voice becomes normal.Increased Activity of Sweat andSebaceous Glands:During puberty the secretion of sweatglands and sebaceous glands (oil glands)increases. Many young people get acneand pimples on the face at this timebecause of the increased activity of theseglands in the skin.Development of Sex Organs: At puberty, malesex organs like the testes and penisdevelop completely. The testes alsobegin to produce sperms. In girls, theovaries enlarge and eggs begin tomature. Also, ovaries start releasingmature eggs.Reaching Mental, Intellectual andEmotional MaturityAdolescence is also a period of changein a person’s way of thinking.Adolescents are more independent thanbefore and are also self-conscious.Intellectual development takes place andthey tend to spend considerable timethinking. In fact, it is often the time inone’s life when the brain has thegreatest capacity for learning.Sometimes, however, an adolescent mayfeel insecure while trying to adjust tothe changes in the body and mind. Butas adolescent learners, you should knowthat there is no reason to feel insecure.These changes are a natural part ofgrowing up.

Que. 1) The protruding part of the throat usually seen in boys that is responsible for deep voice is known as?

(a) Goitre

(b) Swollen lymph

(c) Adam’s apple

(d) Thyroid

Que. 2) Which of the following is a change in body shape usually observed in girls?

(a) Broader shoulder

(b) Increased muscle growth

(c) Deep voice

(d) Region below waist wider

Que. 3) During the puberty ………………………………………………………………………………..starts releasing mature eggs in girls.

(a) Ovaries

(b) Testes

(c) Oviduct

(d) Sperm

Que. 4) Describe the development of secondary sex organs in males.

Que. 5) Why do we observe acne or pimples on the face of young people at the age of adolescence?

Answer Key

Que. 1) (c) Adam’s apple

Que. 2) (d) Region below waist wider

Que. 3) (a) Ovaries

Que. 4) Answer: In males, sex organs like testes and penis develop completely at puberty. The testes begin to produce sperms.

Que. 5) Answer: During puberty the secretion of sweat glands and sebaceous glands (oil glands) increases. Pimples are seen due to increased activity of these glands.

Case study 2

Secondary Sexual: CharactersYou have learnt in Chapter 9, thattestes and ovaries are the reproductiveorgans. They produce the gametes,that is, sperms and ova. In girls,breasts begin to develop at pubertyand boys begin to grow facial hair, thatis, moustaches and beard. As thesefeatures help to distinguish the malefrom the female, they are calledsecondary sexual characters. Boysalso develop hair on their chest. Inboth, boys and girls, hair grows underthe arms and in the region above thethighs or the pubic region.The changes which occur atadolescencearecontrolledbyhormones. Hormones are chemicalsubstances. These are secretions fromendocrine glands, or endocrine system.The male hormone or testosteronebegins to be released by the testes atthe onset of puberty. This causeschanges in boys about which you havejust learnt, for example, the growth offacial hair. Once puberty is reached ingirls, ovaries begin to produce the femalehormone or estrogen which makes thebreasts develop. Milk secreting glandsor mammary glands develop inside thebreasts. The production of thesehormones is under the control ofanother hormone secreted from anendocrine gland called pituitary gland.Role of Hormones inInitiating ReproductiveFunctionEndocrine glands release hormonesinto the bloodstream to reach aparticular body part called target site.The target site responds to thehormone. There are many endocrineglands or ductless glands in the body.The testes and ovaries secrete sexhormones. You have just learnt thatthese hormones are responsible for themale and female secondary sexualcharacters. Further, the sex hormonesare under the control of hormones fromthe pituitary gland. Thepituitary secretes many hormones, oneof which makes ova mature in theovaries and sperms form in the testes.

Que. 1) Sex hormones are under the control of hormones from the ………………………………………………………………………………….. gland.

(a) Adrenal

(b) Pituitary

(c) Thyroid

(d) Thymus

Que. 2) Which among the following is the example of a major male sex hormone?

(a) Testosterone

(b) Estrogen

(c) Prolactin

(d) Follicle stimulating hormon

Que. 3) The endocrine gland is generally also known as ……………………………………………………………………………………….

(a) Superficial glands

(b) Doubtful glands

(c) Funny glands

(d) Ductless glands

Que. 4) Define the term “Hormone”.

Que. 5) Name some of the secondary sexual characters observed in girls.

Answer Key

Que. 1) (b) Pituitary

Que. 2) (a) Testosterone

Que. 3) (d) Ductless glands

Que. 4) Answer: Hormones are chemical substances which are secreted from endocrine gland or endocrine system.

Que. 5) Answer: Some of the secondary sexual characters seen in girls include development of breast, hair growth under the arm and pubic region, mammary gland develops inside the breast.

Case study 3

Reproductive Phase of Life in Humans: Adolescents become capable of reproduction when their testes and ovaries begin to produce gametes. Thecapacity for maturation and production of gametes lasts for a much longer timein males than in females. In females, the reproductive phase of life begins at puberty (10 to 12 years of age) and generally lasts till the age of approximately 45 to 50 years. The ovabegin to mature with the onset of puberty. One ovum matures and isreleased by one of the ovaries once inabout 28 to 30 days. During thisperiod, the wall of the uterus be comes thick so as to receive the egg, in caseit is fertilised and begins to develop. This results in pregnancy. If fertilisation does not occur, the released egg, and the thickened lining of the uterus along with its blood vessels are shed off. This causes bleeding in women which is called menstruation. Menstruation occurs once in about 28 to 30 days. The first menstrual flow begins at puberty and is termed menarche. At 45 to 50 years of age, the menstrual cycle stops. Stoppage of menstruation is termedmeno pause. Initially, menstrual cycle may be irregular. It takes some time to become regular. Menstrual cycle is controlled by hormones. The cycle includes the maturation of the egg, its release, thickening of uterine wall and its breakdown if pregnancy does not occur. In case the egg is fertilised it begins to divide and then gets embedded in the uterus for further development as you have learnt inChapter 9How is the Sex of the Baby Determined? Inside the fertilised egg or zygote is the instruction for determining the sex of the baby. This instruction is present inthe thread-like structures, called chromosomes in the fertilised egg.RecallfromChapter8,thatchromosomes are present inside the nucleus of every cell. All human beings have 23 pairs of chromosomes in the nuclei of their cells. Two chromosomes out of these are the sex chromosomes, named X and Y. A female has two X chromosomes, while a male has one X and one Y chromosome. The gametes(egg and sperm) have only one set of chromosomes. The unfertilised egg always has one X chromosome. But sperms are of two kinds. One kind has an X chromosome, and the other kind has a Y chromosome. See Fig. 10.4. When a sperm containing X chromosome fertilises the egg, the zygote would have two X chromosomes and develop into a female child. If the sperm contributes a Y chromosome to the egg (ovum) at fertilisation, the zygote would develop into a male child. Now you know that the sex chromosomes of the father determine the sex of an unborn baby. The belief that the mother is responsible for the sex of her baby is completely wrong and to blame her for this is totally unjustified.

Que. 1) The first menstrual flow begins at puberty and is termed as………………………………………………………………………………………..

(a) Menopause

(b) Premenstrual syndrome

(c) PCOD

(d) Menarche

Que. 2) If a baby has XY chromosomes in its nucleus, then the sex of the baby is?

(a) Female

(b) Male

(c) Both (a) and (b)

(d) None of the above

Que. 3) Which among the following is NOT an event of menstruation in female?

(a) Thickening of uterus wall

(b) Fertilisation of ovum and sperm

(c) Release of matured ovum

(d) Shedding of blood vessels and ovum

Que. 4) Explain in detail the process of menstruation.

Que. 5) Name the possible sex chromosomes present in the male and female gametes.

Answer Key

Que. 1) (d) Menarche

Que. 2) (b) Male

Que. 3) (b) Fertilisation of ovum and sperm

Que. 4)Answer: In about 28-30 days, one ovum maturesand is released from the ovary. Walls of the uterus are thickened to receive the ovum. If fertilisation of that ovum does not occur, the released ovum along with the thickened lining and its blood vessels are shed off causing bleeding.

Que. 5) Answer: Sex chromosomes present in ovum (female gamete) is always X chromosome. The sperms (male gamete) are of two kinds: one kind has X chromosome and the other kind has Y chromosome.

Case study 4

Hormones other than Sex Hormones: The hormones secreted by the pituitary stimulate testes and ovaries to produce their hormones. You have already learnt that the pituitary gland is an endocrine gland.It is attached to the brain.Apart from the pituitary, the testesand the ovaries, there are otherendocrine glands in the body such as thyroid, pancreas and adrenals. Boojho and Paheli had once visitedtheir aunt who was a doctor and remembered that a boy named Kaka hada very big and bulging throat. Their aunt had told them that Kaka was sufferingfrom ‘goitre’, a disease of the thyroid gland. Kaka’s thyroid gland was notproducing the hormone thyroxine. Their aunt also told them that theiruncle was suffering from ‘diabetes’ because his pancreas was not producing the hormone insulin in sufficient quantities. Boojho and Paheli thenasked their aunt about the adrenal glands, which are also shown in the chart hung on the wall of her clinic. Theaunt told them that adrenal glands secrete hormones which maintain thecorrect salt balance in the blood. Adrenals also produce the hormone adrenalin. It helps the body to adjustto stress when one is very angry, embarrassed or worried. Thyroid and adrenals secrete their hormones when they receive orders from the pituitary through its hormones. Pituitary also secretes growth hormone which is necessary for the normal growth of a person. Role of Hormones in Completing the LifeHistory of Insects and Frogs:You have already learnt about the lifehistory of the silk moth and the frog. The caterpillar has to pass throughvarious stages to become an adult moth. Recall from Class VII the stages of thelife history of the silk moth. Similarly, the tadpole passes through certain stages to become a frog (Chapter 9).This change from larva to adult iscalled metamorphosis (Fig. 9.10).Metamorphosis in insects is controlled by insect hormones. In a frog, it iscontrolled by thyroxine, the hormone produced by thyroid. Thyroxine production requires the presence ofiodine in water. If the water in whichthe tadpoles are growing does not contain sufficient iodine, the tadpoles cannot become adults.

Que. 1) If the thyroid gland of a person is not producing thyroxine hormone, he/she is suffering from………………………………………………………………………………..

(a) Goitre

(b) Mumps

(c) Chicken pox

(d) Diabetes

Que. 2) Metamorphosis in frog is controlled by which of the following hormones?

(a) Insulin

(b) Testosterone

(c) Estrogen

(d) Thyroxine

Que. 3) In a person suffering from Diabetes, the pancreas does not produce ……………………………………………………………………………………..hormone in sufficient quantity.

(a) Adrenalin

(b) Thyroxine

(c) Insulin

(d) Melatonin

Que. 4) Explain the role of adrenal glands.

Que. 5) Name some of the endocrine glands in the human body.

Answer Key

Que. 1) (a) Goitre

Que. 2) (d) Thyroxine

Que. 3) (c) Insulin

Que. 4) Answer: Adrenal glands produce hormone adrenalin, which helps the body to adjust to stress when the person is angry, embarrassed or worried.

Que. 5) Answer:Some of the endocrine glands include: Thyroid, pancreas, adrenal, testes, ovary and pituitary gland.

Updated: March 15, 2022 — 10:13 pm

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