BACKGROUND:
Growth in humans refers to an increase in size.
The two ways that growth is accomplished in an organism is by an enlargement
of cell size and through an increase of the number of cells in that organism.
Some organisms stop growing at maturity, others continue to grow
throughout their lives (i.e. many plants). Living things grow and
change. The stages an organism goes through between birth and death
is called the life cycle.
The human life cycle begins as a single cell and through countless
cell divisions develops into an embryo then a fetus and ultimately a child
which is born within nine months. For several months after birth,
a baby is in the stage called infancy. As babies produce more cells
they grow and enter childhood. Here a child begins to walk and talk.
A stage of rapid growth and change occurs during the teen years called
adolescence. At about 20 or so a person enters adulthood. At
this stage full growth is reached (in height, not waist size!) and is representative
of the longest stage in the human life cycle.
PROCEDURE:
- Review the human body systems before emphasizing
human growth. Discuss the different parts of the human body by using
the Human Body Placemats to examine the different systems.
- Give students worksheet and see if they can figure the
answers. This worksheet should be more of a homework assignment,
where students are forced to look at people in their community that might
be the age they are looking for.
- The following are the approximate answers to the worksheet.
Baby with diaper is usually 1-12 months, although some children take longer.
Baby walks between 9-12 months. Baby talks between 9-12 months.
Child goes into the 5th grade about 10 years old, graduates high school
around 17-18, begins working around 18-20, retires around 60-65 and dies
around 65-100.
