```GENETIC VARIATIONS IN HAND SPAN SIZE

RICHARD CHILTON                CHICAGO VOCATIONAL HIGH SCHOOL
2100 EAST 87TH STREET
CHICAGO, IL
1-312-978-1600

OBJECTIVE:
Students shall measure their handspan size to determine if one pair or many
pairs of genes control that trait.

MATERIALS:
Metric rulers, Basketball, Lab. Worksheet, Graph paper, and Graphic
overlays.

STRATEGIES:
Obtain a metric ruler, lab. worksheet and graph paper. Measure your
handspan size as demonstrated by teacher, spreading out your hand on a
sheet of paper.  Draw a line from the tip of your thumb to the tip of your
little finger.  Do not include length of fingernails.  Measure the length
of the line (your handspan)  in millimeters.  Record the measurements of
all members of your class on the chalkboard. Organize the measurements into
a graph showing handspan size  in groups of 5 mm. Also record the number of
students in each group. Draw a graph of the data in the table. Then carry
Basketball out to students to see if students can place handspan across the
Basketball and hold in place without touching any object. Next, answer the
following questions:

(1) What does the graph reveal about the differences in handspans within