Partnerships f or Reform through I nvestigative Science and Math
Happy-Face Spiders
1
Concepts
Genes are passed on
from one generation to
the next and this is the
concept of heredity.
Genes code for what an
organism will look like
and are carried by
chromosomes.
Chromosomes, which
occur in nearly identical
pairs in the nucleus of
every cell, are
responsible for passing
on hereditary
information. Depending
on which alleles an
organism has will
determine how the
organism will look and
behave.
HCPS III Benchmarks
SC 7.5.2 SC 7.5.3
SC 7.5.6
Duration
(2) One-hour periods
Source Material
PRISM
Vocabulary
Genotype
Happy-face Spider
Heterozygous
Homologous
Homozygous
Phenotype
Probability
Punnett square
Morphs
Happy-Face Spider Propagation
Summary
Students will act as captive breeders in order to simulate how genes
are passed on from one generation to the next. They will also
observe how small differences accumulate over time to produce
descendants that look very different from their ancestors. Students
will use the Happy-face spiders (Theridion grallator), a spider that is
endemic to the Hawaiian Islands and exhibits genetic variation.
Spiders on the island of Maui follow basic Mendelian genetic
patterns, so they will be useful organisms for this lesson. This
simulation will help students determine how genetic information is
transferred during breeding, and what the resulting phenotype (how
they look) will be. They will decide which traits are most important
to breed in order for better survival for the spiders. Students will also
be introduced to Punnett squares, which will be used to predict the
proportion of offspring with each trait.
Objectives
• Students will learn about a species that is endemic to Hawaii
• Students will simulate how genes are passed from one
generation to the next.
• Students will act as captive breeders and choose which traits
will help the survival of the spiders.
• Students will use Punnett squares to predict the proportion or
frequency of which genes will be passed on.
Materials
Pictures of Happy-face spiders that show variation in color.
Pink and Blue Card Stock-each group of 2 students should have a
total of 12 pink cards and 12 blue cards. (Size of playing cards).
Need one set for use in explaining concept to students.
Clear transparency to go over Punnett squares
Paper for student Punnett squares.
Hand-out of Happy-face Spider for students to color using their
color choice.
Making Connections
Students will recall previous knowledge they acquired in the previous
Exploring Human Traits lesson to delve further into the world of
genetic variation. The charismatic and native Hawaiian arthropod,
the Happy-face spider, will be used to explore the myriad physical
distinctions in spider appearances due to different genotypes (i.e.
genetic fingerprint, alleles).
GENETIC
VARIATION
