Page 1 - 2.Lesson Notes-Changes at puberty-I

SAI International School
Subject- Biology, Class-VIII
Topic- Reaching the age of adolescence
Subtopic- Changes at puberty-I
Module- 19
Lesson Notes
1. Increase in height

There is a sudden increase in height.

Initially girls grow faster than boys. By about 18 years of age, both boys and girls reach
their maximum height.

Height of an individual (male or female) depends on the genes inherited from parents.
However certain environmental factors, such as nutrition and exercise are also
essential.

The rate of growth in height varies in different persons:Some boys and girls may
grow suddenly at puberty and then slow down, while others may grow gradually. All the
parts of the body do not grow at the same rate. Sometimes, the arms and legs or hands
and feet of adolescent boys and girls look oversized and out of proportion with the body.
But soon the other parts catch up with them in growth. This results in a more
proportionate body.

In this growing time, it is very important to eat the right kind of food which helps the
bones, muscles and other parts of the body get adequate nourishment for growth.

Calculation for full height (cm):

The average rate of growth in the height of boys
and girls with age given in the chart helps in
calculating full height of the individuals.