Last updated on February 9th, 2024 at 04:38 pm
CG Board Class 8 Science Adolescence Notes / Textbook Exercises and Extra Question and Answers.
Find out the correct and incorrect sentences.
1. Mothers are responsible for the sex of the unborn child.[Incorrect – father is responsible]
2. Children gain height during adolescence.[correct]
3. During menstruation girls should not be allowed to work in kitchen.[incorrect – it is a myth]
4. Children in the age group of 13-19 are called infants.[incorrect – 13-19 are called adolescents]
5. The zygote with XY chromosome pair develops into a male child.[correct]
6. Body of girls becomes unholy during menstruation.[incorrect]
Choose the correct option –
i. Adolescents should be careful about what they eat, because-
A. Proper diet develops their brains.
B. Proper diet is needed for the rapid growth taking place in their body.[answer]
C. Adolescents feel hungry all the time.
D. Taste buds are well developed in teenagers.
ii. Reproductive age starts when –
A. Menstruation starts.[answer]
B. Breasts start developing.
C. Body weight increases.
D. Height increases.
iii. The right meal for adolescents consists of –
A. Chips, noodles, chocolate
B. Chapatti, dal, vegetables [answer]
C. Rice, noodles and chips
D. Vegetable, chips and cold drink.
iv. Following is male hormone –
A. Testosterone [answer]
B. Estrogens
C. Insulin
D. Thyroxin
Answer These
Q: Which chromosomes are responsible for the determination of sex in human?
In humans, sex is determined by the sex chromosomes, X and Y. Females have two X chromosomes (XX), and males have one X and one Y chromosome (XY).
Q: Name the hormones responsible for the changes occurring in adolescence at puberty.
The hormones responsible for changes in adolescence at puberty are testosterone in males and estrogen in females
Q: What is the span of reproductive life in females?
The span of reproductive life in females starts at puberty (around 10-12) and typically ends at menopause (around 45-50).
Q: Mention the main characteristics of adolescence?
Adolescence involves rapid growth, the onset of puberty, the development of secondary sexual characteristics, intellectual development, emotional changes, and complex decision making.
Q: What are the reasons of acne and pimples on the face of adolescents?
Acne and pimples in teens are caused by increased activity of sweat and oil glands, hormonal changes, genetics, and skin care habits.
Q: What are the main differences between viviparous and oviparous animals?
Viviparous animals give birth to live offspring, but egg-laying animals have different reproductive strategies.
Q: What is fertilisation? Explain
Fertilization is a process during which a male sperm cell fuses with a female egg cell, forming a zygote, which is the initial stage of development of a new organism. This can happen internally or externally, depending on the reproductive process of the species.
