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Key Ideas

  • Physical growth and development are a function of two factors-heredity and environment.
  • During puberty, height and weight increase, muscles develop, and the body assumes new proportions of fat and muscle, depending on gender, nutrition, and heredity.
  • There are a number of common health concerns during puberty. Acne and good nutrition are among the most common concerns. Regular visits to the doctor and learning about what happen to your body during puberty will help you stay healthy.


This section focuses on height, weight, and muscle gain, as well as a variety of health concerns during puberty. Students use charts to examine the average height of boys and girls at a given age, and the average age at which the growth spurt occurs. The fact that average and normal are not the same is emphasized. Students see that it is perfectly normal to be taller or shorter than the average figure. Acne and scoliosis are two problems associated with adolescence that are addressed in this section.



\checkmark examine average heights and average rates of growth.

\checkmark interpret a graph.

\checkmark compute percentage.

\checkmark determine the factors influencing height, weight gain, and muscle development.


chronic, endurance, genes, heredity, proportions

Student Materials

Activity 2-1: How Tall?

  • Activity Report
  • 1 ruler per student if possible, or per group (pairs are suggested)

Teacher Materials

Activity 2-1: How Tall?

  • Activity Report Answer Key

Advance Preparation

See Activity 2-1 in the student edition

Activity 2-1: How Tall?

  • Gather rulers.
  • Make a transparency of the two graphs in the exercise to make explanation and discussion easier. (Optional)

Interdisciplinary Connection

Math Proportion is discussed, as are averages. Students read curves and interpret charts and graphs.

Background Information

The primary determinants of growth patterns are genetic. There is a species-specific pattern. For example, there are not 20-feet-tall humans. However species-specific patterns are modified by racial differences (Africans from the Nile Valley are taller than Pygmies) and familial variations (tall parents tend to have tall children).

However, these basic genetic patterns can be greatly influenced by nutritional and other environmental factors. Malnutrition leads to stunted growth. Even psychological factors, such as severe stress, can interfere with normal growth. Further variations on this normal pattern are influenced by illness typically affecting the pituitary gland (which produces growth hormone) that can lead to various forms of dwarfism and gigantism.

This section provides an excellent opportunity to discuss the interaction of genetics (over which we have little control), with the physical environment (over which we have more control), and the social environment (which is of our own making).

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Date Created:

Feb 23, 2012

Last Modified:

Apr 29, 2014
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