Biology

• Adolescence is the period of life when the body undergoes changes leading to reproductive maturity
• Adolescence begins around the age of 11 and lasts up to 18 or 19 years of age
• Adolescents are also called 'teenagers' as this period covers the 'teens' (13 to 18 or 19 years of age)
• In girls, adolescence may begin a year or two earlier than in boys, and the period of adolescence varies from person to person
• Puberty is marked by the most important change where boys and girls become capable of reproduction
• Puberty ends when an adolescent reaches reproductive maturity
• Girls initially grow faster than boys, but both reach their maximum height around 18 years of age
• Boys experience broader shoulders and wider chests during puberty, while girls see widening in the region below the waist
• Muscles grow more prominently in boys than in girls during adolescence
• Voice changes occur in boys due to the growth of the voice box or larynx, leading to a deeper voice
• Girls generally have a high-pitched voice, while boys develop a deep voice during adolescence
• Increased activity of sweat and sebaceous glands during puberty can lead to acne and pimples on the face
• Male sex organs like testes and penis develop completely during puberty, with testes starting to produce sperms
• In girls, ovaries enlarge, eggs begin to mature, and mature eggs are released during puberty
• Hormones play a crucial role in initiating and controlling the changes that occur during adolescence
• Hormones are chemical substances secreted from endocrine glands
• Testosterone is the male hormone that begins to be released by the testes at the onset of puberty
• Estrogen is the female hormone that ovaries begin to produce at puberty, leading to breast development
• Endocrine glands release hormones into the bloodstream to reach target sites in the body, stimulating changes at the onset of puberty
• The reproductive phase of life in humans begins at puberty and generally lasts till around 45 to 50 years of age
• In females, the reproductive phase involves the maturation and release of ova, with the menstrual cycle controlled by hormones
• The sex of a baby is determined by the chromosomes present in the fertilized egg, with the father's sex chromosomes determining the sex of the baby
• Hormones play a significant role in completing the life history of insects and frogs, including metamorphosis processes
• Pituitary gland is know as the master gland
• Iodine is important for thyroid
• Low thyroid is hypothyroidism, high thyroid is hyperthyroidism
• 'Goitre' is a disease of thyroid
• Chromosomes has 23 pairs and 46 Chromosomes. 22 pairs are autosomes 23rd pair is the sex Chromosome
• Secondary sexual characters help to distinguish between a male and a female