Answer: Option C. -> Breast development
:
C
One of the major changes in girls during puberty is the breast development. Also, in girls, the region below the waist becomes wider during puberty while in boys the chest becomes wider and shoulders become broad.

Answer: Option A. -> One pair
:
A
Humans have 46 chromosomes i.e. 23 pairs of chromosomes in all cells except for the gametic cells (sperm and ova). 22 of these pairs are called autosomes and look the same in both males and females. The 23rd pair called sex chromosomes, differ in males and females. Females have two copies of the X chromosome (XX), while males have one X and one Y chromosome (XY). Thus all non-gametic cells have 2 sex chromosomes in them.

Answer: Option B. -> adolescence
:
B

Adolescence is the intermediate growing stage between childhood and adulthood. During adolescence, the body undergoes many physical and psychological changes and attains reproductive maturity. This period varies from person to person.

Answer: Option A. -> endocrine glands
:
A

Glands without ducts are called "ductless" or "endocrine" glands. They release their secretions directly into the bloodstream. The pituitary is the master endocrine gland which regulates the secretions of other endocrine glands such as pancreas, thyroid glands, gonads, adrenal glands, etc. The secretions of endocrine glands are called hormones.

Answer: Option A. -> True
:
A
A rapid increase in height, referred to as a growth spurt, usually accompanies puberty. The growth spurt characteristically occurs earlier in girls than in boys, with girls having the growth spurt approximately two years prior to boys, on average. In girls, the growth spurt typically slows down by the onset of menstruation. Hence, growth of girls stops earlier than boys.

Answer: Option B. -> A proper diet is needed for the rapid growth taking place during adolescence.
:
B

Adolescence is a very important phase for an individual as maximum growth takes place during this phase. If an individual does not receive proper diet during this crucial period, his/her development might be hampered.

Answer: Option C. -> (i) Growth hormone - releasing hormone, (ii) Pituitary gland
:
C

The hypothalamus regulates all the secretions of the master gland pituitary, which in turn regulates the secretions of all other endocrine glands. In the given flow chart, the hypothalamus secretes growth hormone - releasing hormone, which stimulates the pituitary gland to release growth hormone (GH). This hormone is responsible for increasing height by causing elongation of limbs in both boys and girls.

Answer: Option B. -> Pimples get cured with age.
:
B and D

An overdrive of oil glands during adolescence leads to blockage of skin pores. This leads to the formation of acne or pimples due to microbial activity. It is a common phenomenon and adolescents should not lose confidence or feel depressed about it. The excessive pimple outbreak is only a passing phase and will be cured with age. 

Answer: Option D. -> hypothalamus
:
D

The pituitary gland is a pea-sized gland located just below the hypothalamus which is connected to the pituitary via a bundle of nerve fibres. It is known as the master gland of the endocrine system as it produces all the critical hormones which regulates  the secretions of all other endocrine glands.

Answer: Option B. -> (22+1) pairs
:
B

• There are 22 pairs of autosomes and one pair of  allosomes (also called sex chromosomes), thus a total of 23 pairs of chromosomes.


• In human karyotype, the autosome pairs are labelled with numbers, while the sex chromosomes are labelled with letters. Females (44+XX) have two X chromosomes while males (44+XY) contain one X and one Y chromosome.