Dramatic changes of body features associated with puberty are mainly because of secretion of

(c) cracking of voice

(c) (iii) and (iv)

Correct Option: A  Internal fertilization occurs inside female body

Changes at puberty:   Sudden increase in height.   Broadening of shoulders and widening of chest in boys. In girls, the region below waist becomes wider.   At puberty, the voice box or...

During the early period, irrigation was done by Persian wheel. Diesel operated or electricity operated pumps have replaced the Persian wheels. Tractors have replaced bullocks for ploughing the large farms....

Oestrogen from the ovaries of girls and testosterone from testes of boys

Physical Changes: (b) Dissolving sugar in water, (d) Melting of wax, (e) Beating Aluminium to make Aluminium foil. Chemical Changes: (a) Photosynthesis, (c) Burning of coal, (f) Digestion of food

Physical Changes: On heating, candle wax gets melted is a physical change. Since it again turns into solid wax on cooling. Chemical Changes: The wax near to flame burns and gives...

(a) The nutrients which mainly give energy to our body – Carbohydrates and Fats (b) The nutrients that are needed for the growth and maintenance of our body - Proteins (c) A...

(d) : The centre of mass of bodies B and C taken together does not shift as no external force is applied horizontally.