Reaching the Age of Adolescence — Question 8
Back to all questionsQuestion 7(b)
Reproductive age in women starts when their
- menstruation starts.
- breasts start developing.
- body weight increases.
- height increases.
menstruation starts.
Reason — Start of menstruation marks end of puberty and start of reproductive age.
Key Concepts Covered
This question tests your understanding of the following concepts from the chapter Reaching the Age of Adolescence: Question, Reproductive, Age, Women, Starts, Menstruation. These are fundamental topics in Science that students are expected to master as part of the CBSE Class 8 curriculum.
A thorough understanding of these concepts will help you answer similar questions confidently in your CBSE examinations. These topics are frequently tested in both objective and subjective sections of Science papers. We recommend revising the relevant section of your textbook alongside practising these solved examples to build a strong foundation.
How to Approach This Question
Read the question carefully and identify what is being asked. Break down complex questions into smaller parts. Use the terminology and concepts discussed in this chapter. Structure your answer logically — begin with a definition or key statement, then provide supporting details. Review your answer to ensure it addresses all parts of the question completely.
Key Points to Remember
- Read the question carefully and identify all parts before answering.
- Use the terminology specific to this subject and chapter.
- Review the textbook content for this chapter before attempting questions.
- Practice writing concise, well-structured answers within time limits.
Practice more questions from Reaching the Age of Adolescence — Science, Class 8 CBSE
Chapter Overview: Reaching the Age of Adolescence
This chapter covers the physical and emotional changes during adolescence and puberty, the role of hormones secreted by endocrine glands, sex determination in humans (XX/XY), and the importance of balanced nutrition, personal hygiene, and avoiding harmful substances during this critical growth period.
Board Exam Weightage: 4-6 marks | Difficulty: Moderate
Key Formulas & Concepts
| Concept | Details |
|---|---|
| Sex Determination | XX = Female; XY = Male; Father's sperm determines sex |
| Thyroxine | Thyroid hormone; controls metabolism; needs iodine; deficiency → goitre |
| Insulin | Pancreatic hormone; controls blood sugar; deficiency → diabetes |
| Puberty Age | Girls: ~11 years; Boys: ~13 years (approximate onset) |
Must-Know Concepts
- Adolescence spans ages 11-19; puberty is the onset of reproductive maturity within this period
- Secondary sexual characters: visible physical changes at puberty (facial hair in boys, breast development in girls)
- Adam's apple is the enlarged voice box in boys (causes deeper voice)
- Pituitary is the master gland (controls other endocrine glands)
- Sex is determined by the father's sperm (X → girl, Y → boy), not by the mother
- Balanced diet, exercise, hygiene, and avoiding drugs are essential during adolescence
Endocrine Glands and Hormones
| Gland | Hormone | Function |
|---|---|---|
| Pituitary (brain) | Growth hormone | Controls body growth; master gland |
| Thyroid (neck) | Thyroxine | Controls metabolism; needs iodine |
| Pancreas (abdomen) | Insulin | Regulates blood sugar |
| Adrenal (on kidneys) | Adrenaline | Fight or flight response |
| Testes (males) | Testosterone | Male sexual characters, sperm production |
| Ovaries (females) | Oestrogen | Female sexual characters, egg development |
Common Mistakes to Avoid
- Thinking the mother determines the sex of the child (father's sperm determines it)
- Confusing adolescence (age period) with puberty (onset of changes)
- Mixing up endocrine (ductless, hormones into blood) and exocrine (duct) glands
- Thinking hormones act instantly like nerve impulses (they are slower)
Scoring Tips
- Draw the XX/XY cross diagram to explain sex determination
- Create a hormone-gland-function table for quick revision
- Learn physical changes during puberty for both boys and girls
- Connect hormonal disorders to glands: goitre → thyroid, diabetes → pancreas
Frequently Asked Questions
Q: How many marks does this chapter carry in the exam?
A: Approximately 4-6 marks in the annual exam.
Q: What question types are commonly asked?
A: MCQs (1 mark), Very Short Answer (2 marks), Short Answer (3 marks), and Long Answer / Diagram (5 marks).
Q: Is this chapter important for competitive exams?
A: Yes, concepts from this chapter appear in NTSE, Olympiad, and other science competitions.