Reaching the Age of Adolescence Class 8 Science (Biology) in One Shot | BYJU'S - Class 8

BYJU'S - Class 6, 7 & 8・2 minutes read

The session covers the chapter "Reaching the Age of Adolescence" and discusses topics like sex determination, puberty, growth, emotional changes, and reproductive health in adolescents. It emphasizes the importance of understanding the physical, emotional, and mental changes that occur during adolescence for overall well-being and development.

Insights

  • The process of sex determination in humans is influenced by the chromosomes present in the sperm and egg during fertilization, ultimately deciding the gender of the baby.
  • Adolescence is a critical stage marked by physical, emotional, and mental changes, including growth spurts, voice changes, brain development, mood swings, and the development of decision-making skills, emphasizing the importance of understanding and supporting individuals during this transitional period.

Get key ideas from YouTube videos. It’s free

Recent questions

  • What determines the sex of a baby?

    Sperm with X or Y chromosomes.

  • What is puberty?

    The stage of sexual maturity.

  • How are growth spurts regulated?

    By the growth hormone.

  • What are secondary sexual changes?

    Indicators of reproductive development.

  • Why is reproductive health important?

    For overall well-being and awareness.

Related videos

Summary

00:00

"Adolescence Chapter Covered in 1 Hour"

  • The session is focused on covering the chapter "Reaching the Age of Adolescence" in one go.
  • Viewers are encouraged to have notebooks, pens, textbooks, and water bottles ready for the session.
  • The goal is to complete the chapter within 1 to 1.5 hours.
  • The channel celebrates reaching 50,000 subscribers and sets new targets of 60,000 or 100,000 subscribers.
  • A like target of 100 likes for the video is set.
  • A parent club event on goal setting is promoted for registration.
  • The session begins with a detailed explanation of the process of life beginning with gametes and zygotes.
  • The importance of chromosomes, with humans having 46 chromosomes or 23 pairs, is highlighted.
  • The last pair of chromosomes, the sex chromosomes, determines the gender of an individual.
  • The sex of a baby is determined during fertilization, with the male gamete (sperm) deciding the sex based on the presence of X or Y chromosomes.

15:37

Stages of life and reproductive maturity.

  • 1. Sperm with X chromosome fusing with egg with X chromosome results in a baby girl with 44 + XX chromosomes.
  • 2. Sperm with Y chromosome fusing with egg with X chromosome leads to a baby boy with 44 + XY chromosomes.
  • 3. Sex determination is the process of understanding how the sex of a baby is determined.
  • 4. Infancy is the phase of life where an individual is born as an infant or a young baby.
  • 5. Childhood is a phase where the body is incapable of reproduction.
  • 6. Adolescence is a transitional stage between childhood and adulthood where reproductive maturity is attained.
  • 7. Puberty is the point in life where the body becomes sexually mature.
  • 8. Physical changes during adolescence include an increase in height due to elongation of bones.
  • 9. Emotional changes and secondary sexual changes are also part of the changes observed during adolescence.
  • 10. Understanding the differences between puberty and adolescence is crucial for comprehending the stages of life and reproductive maturity.

31:37

Growth Hormone and Puberty Changes in Adolescents

  • Growth in height is regulated by the growth hormone, with boys and girls experiencing different rates of growth.
  • Boys initially have slower growth compared to girls, who experience rapid growth, leading to girls often being taller in early school years.
  • Girls reach their maximum height faster due to rapid development, while boys catch up later in life.
  • Maximum height is determined by genetic factors inherited from parents, influencing individual height variations.
  • Growth spurts, characterized by increased growth hormone production, occur during adolescence, leading to rapid height increase.
  • Changes in body shape differ between boys and girls, with boys developing broader shoulders and girls experiencing widening of the hip region.
  • Voice changes during puberty, with boys developing deeper, sometimes hoarse voices, while girls' voices tend to be higher and at times shrill.
  • Voice box enlargement during development leads to the protrusion known as the Adam's Apple, mainly observed in boys.
  • Increased activity of sweat and sebaceous glands during adolescence can result in excessive sweating and oil production, leading to acne and pimples.
  • Acne forms when pores are clogged, while pimples occur when infected, emphasizing the importance of regular face washing for skin health.

47:05

Adolescent Brain Development and Emotional Changes

  • Emotional changes are considered mental changes or changes in the mind, occurring alongside physical development.
  • Brain development occurs during adolescence, leading to increased curiosity and brain activity.
  • Adolescence and early adulthood are optimal for learning due to improved brain capacity.
  • Overthinking is common during this period due to heightened brain activity.
  • Mood swings, increased brain activity, and aggressiveness are typical during this phase.
  • Decision-making skills develop, leading to independence and assertiveness.
  • It is crucial to treat others with kindness and respect, even when disagreements arise.
  • Feelings of anxiety and hyperactivity are normal during this phase, requiring open communication with parents or teachers.
  • Apologizing and owning up to mistakes is essential for personal growth and maintaining relationships.
  • Secondary sexual changes differentiate individuals as male or female, with primary and secondary sexual characteristics indicating reproductive development and physical changes.

01:03:27

"Understanding Hormones and Reproductive Development"

  • Hormones are chemical secretions from the endocrine system, involved in specific reactions in the body.
  • Sex hormones are crucial for the development and control of reproductive organs and secondary sexual characteristics.
  • Testosterone is the male sex hormone produced by the testes, responsible for male reproductive system development and secondary sexual characteristics.
  • Estrogen is the female sex hormone produced by the ovaries, essential for female reproductive system development and secondary sexual characteristics.
  • Progesterone, also produced by the ovaries, is known as the pregnancy hormone, vital for embryo development.
  • Estrogen plays a key role in ovulation, the release of eggs from the ovary, and thickening the uterus lining for embryo implantation.
  • Menstruation occurs when the unfertilized egg and thickened uterus lining shed cyclically every 28 days.
  • Menstruation effects include abdominal cramping, lower back pain, headache, and fatigue.
  • Menarche marks the onset of the reproductive phase in females, leading to menopause around 45-50 years old.
  • The pituitary gland, known as the master gland, produces growth hormone and stimulating hormones to regulate other endocrine glands.

01:19:54

Iodine, Pancreas, Reproductive Health: Key Functions

  • Iodine in water aids in the metamorphosis of organisms like frogs, with tadpoles utilizing this iodine for their development.
  • The pancreas functions as both an endocrine and exocrine gland, producing insulin to regulate blood glucose levels and digestive juices for digestion.
  • Reproductive health involves maintaining physical, mental, and social well-being through balanced diet, hygiene, exercise, and awareness about sexually transmitted diseases like AIDS.
Channel avatarChannel avatarChannel avatarChannel avatarChannel avatar

Try it yourself — It’s free.