NCERT Solutions for Class 8 Science Chapter 10 - Reaching The Age Of Adolescence

1. What  is the term used for secretions of endocrine glands responsible for changes taking place in the body?

Ans: Hormone is that the term used for secretions of endocrine glands responsible for changes happening within the body. The changes which occur in adolescence are controlled by these chemical substances called hormones.

2. Define adolescence.

Ans: Adolescence is the age period of life when the human body undergoes many changes, and this period also will lead to reproductive maturity. This begins from the age of 11 and lasts up to 18 or 19. This age may vary from individual to individual. Adolescents are also called teenagers as this period covers the teens that are 13 to 18 or 19 years of age.

3. What is menstruation? Explain.

Ans: Menstruation occurs in the female after puberty once in about 28 to 30 days. 

Every month, an ovary produces an egg and the uterus is prepared for implantation. During this, the wall of the uterus becomes thick so it receives the egg, just in case it’s fertilized and begins to develop. This results in pregnancy. If fertilization doesn’t occur, this causes bleeding in women which are named menstruation. This happens because of the released egg, and the thickened lining of the uterus along with its blood vessels are shed off. This lasts for 3 to 5 days in a healthy female and this process occurs every month so called as Menstrual cycle. The menstrual cycle is controlled by hormones. Menarche is the first menstrual flow that begins at puberty. The stoppage of menstruation is called menopause this happens at 45 to 50 years of age.

4. List changes in the body that take place at puberty.

Ans: 

Changes at puberty:

• Increase in height.

• Change in body shape.

• Voice change. Changing the pharynx leads to a slight deepening of voice for girls and much deeper in boys.

• Increased Activity of Sweat and Sebaceous Glands. The appearance of facial and pubic hair in boys, while the development of mammary glands in girls is observed.

• Development of Sex Organs. Testis grows and starts producing mature sperms while ovaries start the menstrual cycle to produce eggs.

• Reaching Mental, Intellectual and Emotional Maturity.

5. Prepare a table having two columns depicting names of endocrine glands and hormones secreted by them.

Ans:

Table showing names of endocrine glands and hormones secreted by them is as below,

6. What are sex hormones? Why are they named so? State their function.

Ans: 

• The sex hormones, which are produced by the sex organs. The sex organs in males are the testis and for females, it is the ovaries.

• Testis produces testosterone as a male sex hormone while estrogen is the female sex hormone.

• The function of testosterone: Growth of facial and pubic hairs, deepening of voice, development of reproductive organs etc.

• The function of estrogen: Breast enlargement, change in voice, development of reproductive organs etc.

7. Choose the correct option.

(i) Adolescents should be careful about what they eat, because

• a proper diet develops their brains.

• a proper diet is needed for the rapid growth taking place in their body.

• adolescents feel hungry all the time.

• taste buds are well developed in teenagers.

Ans: 

(ii) Adolescents should be careful about what they eat because a proper diet is needed for the rapid growth taking place in their body.

• Reproductive age in women starts when their

• menstruation starts.

• breasts start developing.

• body weight increases.

• height increases.

Ans: 

(i) Reproductive age in women starts when their menstruation starts.

(a) The right meal for adolescents consists of

• chips, noodles, coke.

• chapati, dal, vegetables.

• rice, noodles and burger.

• vegetable cutlets, chips and lemon drink.

Ans: 

(ii) The right meal for adolescents consists of chapati, dal, vegetables.

8. Write notes on −

(a) Adam’s apple.

Ans: The larynx or voice box in males begins to grow at puberty. . Boys develop larger voice boxes than girls so boys will have a deep voice. In males, the growing voice box may be seen as a protruding part of the throat which is called Adam’s apple.

(b) Secondary sexual characters.

Ans: These are those characteristics that help in distinguishing male and female. The characteristics developed during the time of puberty.

In Male:

• The appearance of mustache, beard, chest hair.

• Deepening of voice.

• Hair growth in the pubic and other parts of the skin. 

In Female:

• Increasing the size of the breast and hips

• Growth of hair at pubic and other parts of the skin.

• Sex determination in the unborn baby.

Ans: Sex determination can be done based on the sex chromosome that fuses together to make the zygote. Every individual has 23 pairs (46 individuals) of chromosomes whether male or female. Out of that 23 pairs, 22 pairs are the same for both males and females. The last one is called as sex chromosome. In the male sex, the chromosome is XY while in the female sex chromosome is XX. During gamete formation the male produces two types of gametes X gamete and Y gametes while the female produces two X gametes.

So, during fusion females will always give 22+X always while males can give 22+X or       22+Y.

Depending on which one fuses with 22+X (given by female) the sex of the unborn baby is decided.

22+X (F) + 22+X (M) = girl child 

22+X (F) + 22+Y (M) = boy child

So, X and Y chromosome is the deciding factor for the sex of the unborn kid.

9. Word game: Use the clues to work out the words. Across

• Protruding voice box in boys

• Glands without ducts

• Endocrine gland attached to the brain

• Secretion of endocrine glands

• Pancreatic hormone

• Female hormone Down

• Male hormone

• Secretes thyroxine

• Another term for teenage

• Hormone reaches here through the bloodstream

• Voicebox

• Term for changes at adolescence

Ans: 

Across

• Adam’s Apple

• Endocrine

• Pituitary

• Hormone

• Insulin

• Estrogen

Down

• Testosterone

• Thyroid

• Adolescence

• Target Site

• Larynx

• Puberty

10. The table below shows the data on the likely heights of boys and girls as they grow in age. Draw graphs showing height and age for both boys and girls on the same graph paper. What conclusions can be drawn from these graphs?

Ans: 

Image: Graph showing height and age for both boys and girls.

The graph depicts the relation between the age and height for both boys and girls. During puberty, there’s a sudden increase in height of both boys and girls. Based on the above graph, it can be observed that during the age of 4-8 years, girls have less height as compared to boys. However, as soon as girls reach 12- 13 years, their height shows a sudden increase which is more than boys. In later years, growth in both boys and girls becomes stable. Growth during puberty is under the control of hormones.

NCERT Solutions for Class 8 Science Chapter 10 - Reaching The Age of Adolescence

Science NCERT Grade 8, Chapter 10, Reaching the Age of Adolescence lays emphasis on the role that hormones play in bringing about modifications that make a baby develop into an adult. In the preliminary part of the discussion, the chapter described the 2 essential terms: adolescence and puberty. Thereafter, essential modifications that take region in the course of puberty are defined under the subsequent labels:

• Increase in height

• Changes in body shape

• Voice change

• The increased activity of sweat and sebaceous glands

• Development of intercourse organs

• Reaching mental, intellectual, and emotional maturity

• Each of the above subjects is defined with the assistance of suitable examples, diagrams, and activities. In the subsequent section, the secondary sexual traits of males and females are considered accompanied by a discussion of the role of hormones in initiating reproductive functions.

The complete process of intercourse determination of a baby is discussed through a diagram along with the explanation of the importance of other hormones in the body in the chapter, Reaching the Age of Adolescence.

The role of hormones in completing the life cycle of insects and frogs is likewise blanketed in detail in the chapter, Reaching the Age of Adolescence. The remaining part of the chapter specializes in reproductive health wherein, personal hygiene and physical exercise are given due importance. 

The following subjects are blanketed in the chapter, Reaching the Age of Adolescence:

Adolescence and Puberty, Changes at Puberty, Secondary Sexual Characters, Role of Hormones in Initiating Reproductive Function, Reproductive Phase of Life in Humans, How is the Sex of the Baby Determined? , Hormones other than Sex Hormones and Role of Hormones in completing the Life History of insects and frogs.

Class 8 Science Chapter 10 Reaching the Age of Adolescence

Adolescence is a stage of extensive growth of physical and mental attributes. This is the stage where the biological maturation of an individual takes place. Biological maturation leads to certain psychological and social developments in teenagers. Right guidance is required to give a proper shaping to a teenager’s development. 

NCERT Solutions Class 8 Science Chapter 10 Consists of Different Sub-Topics Like 

• Age of adolescence 

• Puberty.

• Sexual Characteristics.

• Roles of hormones and reproductive functions.

• Sex determination.

• Importance of reproductive health.

Adolescence has been categorized as the age of adrenaline rushes. This is an age in teenagers, where they need specific attention from their parents or guardians. The age introduces a teenage boy or girl with plenty of changes in their mental and physical attributes.  This is primarily because psychological and physical growth is taken over by puberty. Adolescence is considered a time of significant transitions in a teenager’s physical attributes. 

Reaching the Age of Adolescence Class 8 NCERT solutions can also be helpful for students gaining healthy and safe reproductive health lessons. Vedantu’s team of teachers has adequately concentrated on these aspects. 

Benefits of NCERT Solutions Class 8 Science Chapter 10

Vedantu’s NCERT solutions for Class 8 Science Chapter 10 are designed by the expert team of teachers according to the latest NCERT guidelines and syllabus. 

The benefits of NCERT Science Class 8 Chapter 10 solutions are as follows: 

• To make education more accessible and available, Vedantu has made NCERT solutions for Class 8 Science Chapter 10 Reaching the Age of Adolescence, free, easy to download or read on its website. 

• The PDF of NCERT Class 8 Science Chapter 10 Solutions provides steps to draw diagrammatic representation from the chapter of Adolescence, reproductive parts.  

It further provides questions and answers with proper explanations, multiple-choice questions, and matches the following. 

• The available PDF will provide brief explanations on subtopics like puberty and adolescence, sexual characters of male and female, roles of hormones for beginning reproductive functions and finally, reproductive health. 

If you are still searching for reaching the Age of Adolescence Class 8 solutions PDF, Vedantu’s online NCERT solutions for Class 8 Science Chapter 10 is a great option. 

Chapter Wise NCERT Solutions for Class 8 Science

• Chapter 1 - Crop Production and Management

• Chapter 2 - Microorganisms : Friend and Foe

• Chapter 3 - Synthetic Fibers and Plastics

• Chapter 4 - Materials : Metals and Non-Metals

• Chapter 5 - Coal and Petroleum

• Chapter 6 - Combustion and Flame

• Chapter 7 - Conservation of Plants and Animals

• Chapter 8 - Cell - Structure and Functions

• Chapter 9 - Reproduction in Animals

• Chapter 10 - Reaching The Age of Adolescence

• Chapter 11 - Force and Pressure

• Chapter 12 - Friction

• Chapter 13 - Sound

• Chapter 14 - Chemical Effects of Electric Current

• Chapter 15 - Some Natural Phenomena

• Chapter 16 - Light

• Chapter 17 - Stars and The Solar System

• Chapter 18 - Pollution of Air and Water

Along with this, students can also view additional study materials provided by Vedantu, for Class 8 :

• NCERT Exemplar for class 8 Science Chapter 10

• CBSE Revision Notes for class 8 Science Chapter 10