Question Video: Using a Diagram Which Shows the Growth Rate of Males and Females to Find the Average Age at Which a Girl’s Puberty Begins | Nagwa Question Video: Using a Diagram Which Shows the Growth Rate of Males and Females to Find the Average Age at Which a Girl’s Puberty Begins | Nagwa

# Question Video: Using a Diagram Which Shows the Growth Rate of Males and Females to Find the Average Age at Which a Girl’s Puberty Begins Science • Second Year of Preparatory School

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Many changes occur in the body during puberty. In particular, growth rate increases rapidly. The provided chart shows the growth of a girl and a boy between the ages of 2 and 20. At what age did the girl most likely start her puberty on the basis of the change in her growth?

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### Video Transcript

Many changes occur in the body during puberty. In particular, growth rate increases rapidly. The provided chart shows the growth of a girl and a boy between the ages of two and 20. At what age did the girl most likely start her puberty on the basis of the change in her growth? (A) Around 14, (B) around 11, (C) around eight, or (D) around 15.

This question is asking us to use the growth chart to identify the age at which the girl most likely started puberty. The growth chart shows us how the height of a girl and a boy changes as they increase in age. The question is asking us about the girl, so we will only be referring to the pink line on the chart and can ignore the blue line for the boy.

Let’s first establish what the graph shows us about how the height of the girl changes as her age increases. As the 𝑦-axis indicates height and the 𝑥-axis age, we can deduce that the steeper the line on the graph, the higher the rate of growth. If we look at the pink line indicating the height of the girl, we can see that between around 11 and 13 and a half years of age, there is a period of rapid growth. The girl’s height increases from around 125 centimeters to 157 centimeters during this time period.

You may recall that during puberty, a growth spurt often occurs. A growth spurt is a rapid increase in growth over a short period of time. The beginning of the growth spurt is often a good indicator of the beginning of puberty in an individual. We have established that the growth chart indicates the girl experiences a growth spurt from around 11 years of age. So this is also when she most likely started her puberty.

We are now able to answer our question. The correct answer choice is (B). The age at which the girl most likely started her puberty on the basis of the change in her growth is around 11.

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