GSEB Class 8 Science Solutions Chapter 10 Reaching the Age of Adolescence

Question 1. What is the term used for chemical secretions of endocrine glands responsible for changes taking place in the body?
Answer: Hormones.
In simple words: The chemical messengers produced by endocrine glands that cause body changes are called hormones.

Exam Tip: Remember that hormones are key chemical regulators in the body, initiating many developmental processes, especially during puberty.

 

Question 2. Define adolescence.
Answer: The period of life, when the body experiences changes, resulting in reproductive maturity is called adolescence.
In simple words: Adolescence is the time in life when your body changes and becomes able to have children.

Exam Tip: When defining terms, always include the core concept (life period) and its key outcome (reproductive maturity).

 

Question 3. What is menstruation? Explain.
Answer: When the egg made by the ovary is not fertilized, the egg that is released and the lining that has grown thicker in the uterus, along with its blood vessels, are removed. This results in bleeding in women, and this process is known as menstruation. Menstruation happens approximately every 28 to 30 days.
In simple words: Menstruation is when an unfertilized egg and the thick uterine lining are shed from a woman's body, causing bleeding, usually every 28-30 days.

Exam Tip: When explaining biological processes, clearly describe the sequence of events and the key biological structures involved.

 

Question 4. List the changes in the body that take place at puberty.
Answer: The changes in the body at puberty are:
1. A quick rise in height.
2. The arm and leg bones grow longer, making a person taller.
3. Hair starts growing in various body areas.
4. A boy's voice becomes deeper.
5. Sex organs mature.
6. Boys develop mustaches and beards.
7. Girls' breasts develop and hips get wider, while boys' shoulders typically broaden.
In simple words: During puberty, people experience a sudden height increase, longer limbs, hair growth in new places, a deepening voice for boys, and the maturation of sex organs. Also, boys grow facial hair and get broader shoulders, while girls develop breasts and wider hips.

Exam Tip: For listing changes, ensure you cover both physical growth and the development of secondary sexual characteristics in both sexes.

 

Question 5. Prepare a Table having two columns depicting names of endocrine glands and hormones secreted by them.
Answer:

In simple words: Different glands in your body make specific hormones; for example, the pituitary gland makes growth hormones, ovaries make estrogen, and the pancreas makes insulin.

Exam Tip: When presenting information in a table, ensure clear and concise headings for each column and accurately match each gland to its primary hormone.

 

Question 6. What are sex hormones? Why are they named so? State their functions.
Answer: The hormones which assist and manage the development of secondary sexual characters are called sex hormones. They are called sex hormones because they regulate sex-related processes and help us to tell boys and girls apart. These hormones aid in the growth of secondary sexual characters. For example, in boys, they control sperm production in testes and the growth of facial hair. In girls, they help to develop breasts and milk-producing glands.
In simple words: Sex hormones are chemicals that control secondary sexual traits and help us differentiate between boys and girls. They cause changes like sperm production and facial hair in boys, and breast development in girls.

Exam Tip: When discussing sex hormones, always mention their role in developing secondary sexual characteristics and how they differ in function between males and females.

 

Question 7. Choose the correct option.
(a) Adolescents should be careful about what they eat, because
(i) proper diet develops their brains.
(ii) A proper diet is needed for the rapid growth taking place in their body.
(iii) adolescents feel hungry all the time.
(iv) taste buds are well developed in teenagers.
(b) Reproductive age in women starts when their
(i) menstruation starts.
(ii) breasts start developing.
(iii) body weight increases.
(iv) height increases.
(c) The right meal for adolescents consists of:
(i) chips, noodles, coke.
(ii) chapati, dal, vegetables.
(iii) rice, noodles, and burger.
(iv) vegetable cutlets, chips, and lemon drink.
Answer:
(a) (ii) A proper diet is needed for the rapid growth taking place in their body.
In simple words: A good diet is essential for the fast development happening in their bodies.
(b) (i) menstruation starts.
In simple words: The ability to reproduce begins for women when their menstrual cycle starts.
(c) (ii) chapati, dal, vegetables.
In simple words: A healthy meal for teenagers typically includes chapati, dal, and vegetables.

Exam Tip: For multiple-choice questions, always identify the core concept being tested and choose the option that directly and accurately answers it, avoiding distractors.

 

Question 8. Write notes on:
(a) Adam's apple
(b) Secondary sexual characters
(c) Sex determination in the unborn babies.
Answer:
(a) Adam's apple: The prominent part on the throat of boys is known as Adam's apple. This is the expanded voice box or larynx, which causes boys' voices to become rougher.
(b) Secondary sexual characters: Features that help tell males and females apart are known as secondary sexual characters. These include things like hair on the chest and underarms, breast development, and the growth of beards and mustaches.
(c) Sex determination in unborn babies: The gender of unborn babies is decided by their sex chromosomes. An egg that has not been fertilized always carries X chromosomes. Sperm come in two kinds: one carries an X chromosome, and the other carries a Y chromosome. If a sperm with a Y chromosome joins with the egg during fertilization, the resulting zygote will grow into a male child. If a sperm with an X chromosome fertilizes the egg, the zygote will develop into a female child.
In simple words: (a) Adam's apple is the noticeable part in boys' throats that makes their voice deeper. (b) Secondary sexual characters are physical traits that differentiate males from females, like facial hair in boys or breasts in girls. (c) The baby's sex is determined by the sperm's chromosome (X or Y) fertilizing the egg's X chromosome.

Exam Tip: When writing notes, ensure each point is clear, concise, and covers the essential aspects of the topic as requested in the question.

 

Question 9. Word game: Use the clues to work out the words.
Across:
3. Protruding voice box in boys
4. Glands without ducts
7. Endocrine gland attached to the brain
8. Secretion of endocrine glands
9. Pancreatic hormone
10. Female hormone
Down:
1. Male hormone
2. Secretes thyroxine
3. Another term for teenage
5. Hormone reaches here through the bloodstream
6. Voicebox
7. The term for changes at adolescence.
Answer:
Across:
3. ADAMSAPPLE
4. ENDOCRINE
7. PITUITARY
8. HORMONE
9. INSULIN
10. ESTROGEN
Down:
1. TESTOSTERONE
2. THYROID
3. ADOLESCENCE
5. PITUITARY
6. LARYNX
7. PUBERTY
In simple words: For crossword puzzles, solve each clue one by one, thinking about the topic of the chapter to find the right words that fit the given spaces.

Exam Tip: Crossword puzzles test your vocabulary and understanding of key terms from the chapter; review definitions carefully to fill them out.

 

Question 10. The table below shows the data on 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?

Answer: To draw the graphs, plot Age on the x-axis and Height on the y-axis. Use different colored lines for boys and girls to show their height progression over time. Both graphs will show a general upward trend, indicating increasing height with age, with a noticeable steeper increase during adolescence.

We conclude that initially, girls increase in height more quickly than boys, but both typically achieve their maximum height around 18 years of age. The speed at which height increases differs among various individuals.
In simple words: You plot age and height on a graph, with separate lines for boys and girls. The graphs show that girls grow faster at first, but both boys and girls reach their full height around 18. How fast each person grows can be different.

Exam Tip: When interpreting data from graphs or tables, look for trends, points of intersection, and any significant differences between the categories being compared to form your conclusions.