No, these are not healthy eating habits because burgers and potato chips have very little nutritional value. Although, these are very tasty but can never replace regular meals as balanced diet which is essential for the adolescents for their normal growth and development.

During adolescence, the secretion of sweat glands and sebaceous glands increases leading to the formation of acne and pimples. Regular face wash keeps the face clean and dry and helps to reduce the pimples.

Two features seen in boys at puberty are
(i) Growth of facial hairs.
(ii) Voice becomes hoarse.
Two features seen in girls at puberty are
(i) Development of breasts.
(ii) Region below the waist becomes wider.

(a) No, Rukmini's mother-in-law was absolutely wrong in blaming her.
(b) The sex of a child is determined by the father as the sperm (either X or Y) comes from him. The mother always contributes an X-chromosome as an egg has only X-chromosome.
(c) Rukmini's daughter is caring, intelligent, logical and has scientific aptitude.

(i) The hormones which are responsible for the male and female secondary sexual characters are called sex hormones.
(ii) They are called sex hormones as they control the sexual activities and help us to distinguish boys from girls.
(iii) In boys, sex hormones control formation of sperms by testes and growth of facial hair, etc and in girls, they help to develop breasts, control menstrual cycle, etc.

Hormone is the term used for secretions of endocrine glands responsible for changes taking place in the body.

(a) A specific pair of chromosomes determine the sex of the individual. These are called sex chromosomes, named X and Y.
(b) No, the belief that the mother is responsible for the sex of her baby is completely wrong and to blame her for this is totally unjustified.
It is because the sex chromosomes of the father determine the sex of an unborn baby.
(c) Strong and determined personality with responsibility towards the family and respect for elders.

(a) Adam's apple The protruding part of the growing voice box is called Adam's apple in males. In boys, voice box (larynx) develops larger than girls and this protruding part is seen as bulge in the neck area.
(b) Secondary sexual characters The physical features that help to distinguish the males from the females are called secondary sexual characters. These characters develop at the time of puberty. The secondary sexual characteristics in humans are given below:
In males,
(i) Growth of pubic hair, beard and moustaches.
(ii) Hair on chest and underarms.
In females,
(i) Enlargement of breasts.
(ii) Appearance of pubic hair, hair under arms.
(c) Sex determination of the unborn baby Sex of the unborn baby is determined by the sex chromosomes, i.e. X and Y. A female has two X-chromosomes, while a male have one X and one Y-chromosome.
So in females, the gamete, i.e. egg have only one X-chromosome but in males, the sperm, i.e. male gamete may have an X-chromosome or V-chromosome. If the egg fertilises with sperm containing X-chromosome, the zygote will develop into a female (XX) and if the egg fertilises with sperm containing V-chromosome, the zygote will develop into a male (XY).

Adrenaline hormone maintains the correct balance of salts in the blood.

Testosterone is involved in the development and controls to the reproductive organs and secondary sexual characteristics.

Adam's apple.

Testosterone is the male hormone which is released from the testes at the onset of puberty.