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Which of the following statements is true?
Girls reach puberty earlier than boys. In girls, adolescence may begin a year or two earlier than in boys.
Which of the following represents growth periods labelled as P, Q and R?
Growth is the process in which the size of an individual increases permanently from the zygote stage to the adult stage. The first three years is the infancy period, followed by childhood. Adolescence begins around the age 11 and lasts upto 18 or 19 years of age.
When does adolescence occur?
The period after childhood is that of the adolescence. It begins around the age of 11 and lasts upto 18 or 19 years of age.
What are the two different periods that show rapid growth rate?
Growth takes place by cell division. During infancy growth rate is very fast. Growth slows down during childhood (3-11 years) and during adolescence very rapid growth occurs.
During which of the following stages of growth in height is maximum?
At the beginning of adulthood, the growth is maximum.
What is the role of sperms in reproduction?
The testes produce male gametes called sperms which fertilize the egg to form a zygote.
What causes changes in females at the time of puberty?
Hormones are chemical substances. The changes which occur at adolescence are controlled by hormones. Testosterone is the male hormone. Oestrogen and progesterone are the female hormones.
Which of the following will occur in females at puberty?
The onset of puberty brings about the growth of the reproductive organs. In girls, production of egg cells and menstruation, growth of pubic hair and armpit hair, enlargement of breasts and buttocks take place during adolescence.
A girl has menstruation on the 6th day of the month. When is ovulation most likely to occur?
The release of the egg cell is called ovulation. During menstrual cycle, 13th to 15th day after menstruation, an egg cell is most likely to be released from an ovary.
When do girls overtake boys in height?
Girls reach puberty earlier than boys and they overtake boys in height during adolescence.
In girls, secondary sexual characteristics develop between
The human body undergoes several changes during adolescence. These changes mark the onset of puberty. During puberty, secondary sexual characteristics develop. Girls reach puberty earlier than boys.
Why is a diet rich in proteins essential at puberty?
Adolescence is a stage of rapid growth and development. Hence, a balanced diet rich in proteins is essential.
Which of the following is NOT a secondary sexual characteristic feature of girls?
Deepening of voice is a secondary sexual characteristic of a boy.
Which of the following is/are true of secondary sexual characteristics of boys?
During puberty, physical and emotional changes take place in the adolescents. These changes are called secondary sexual characteristics.
The menstrual cycle stops in a women at about 50 years old. The woman is said to have reached
During menopause, the menstrual cycle stops. It is likely to occur when a woman is about 45 to 50 years old.
Which of the following does not take place during the final stage of the menstrual cycle?
Ovulation take place in the 14th day of menstrual cycle, it does not occur in the final stage
Ovulation typically happens around day 14 of a 28-day menstrual cycle. However, not everyone has a textbook 28-day cycle, so the exact timing can vary. In general, ovulation occurs in the four days before or four days after your cycle's midpoint.
Which of these hormones is secreted by endocrine gland located on the top of kidneys?
Adrenaline hormone is secreted by the adrenal cortex of kidney.
Incomplete development of male secondary sexual characteristics is caused due to deficiency in?
The changes which occur at adolescence are controlled by sex hormones. The male hormone or testosterone controls the development of male secondary sexual characteristics.
Which of the following hormones initiates metamorphosis in insects?
Thyroxine is secreted by the thyroid gland. Metamorphosis in insects is controlled by thyroxine.
Which chromosomes determine the sex of an individual?
Chromosomes concerned with sex are called allosomes or sex chromosomes. They are XX in female and XY in male.