Download Marshmallow Genetic Bugs

Author: Jim Flournoy
Title: Marshmallow Genetic Bugs
Subject Area(s): Life Science - genes
Grade(s): 6,7, and 8th
Description of Lesson: Build models of genetic inheritance that shows random inheritance of dominate and
recessive traits in a small population. Biggest problem is keeping the kids from eating the supplies!!!!
Length of Lesson: one 50-minute class period
Student Objectives: Students will build a model to represent genetic selection and diversity of seven different
genes in putting together their marshmallow bug
Materials: per group
bag of large marshmallows
toothpicks colored with permanent markers
map pins 2 colors
pipe cleaners- 2 colors
push pins- 2 colors
paper bags or envelops - 14
gum drops -green/black
Procedure:
Introduce and show the film "Some Genes are Dominant" from Teacher Domain to help review the role of
different types of genes in genetic outcomes.
http://www.teachersdomain.org/resource/hew06.sci.life.gen.dominantgene/
The teacher will need to create and label the 14 allele sacks/envelops before the lesson for each group of
students.
Step 1-. Create a table that represents the seven traits:
antennae color
number of body segments
tail shape
number of leg pairs
nose color
foot color
number of eyes
Step 2.-Have a column for mom allele, dad allele, baby genotype, baby phenotype
Use the information below to build your baby bug:
RR/Rr= red antennae rr= green antennae - -- colored toothpicks
SS/Ss= 3 body segments ss= 2 body segments--- marshmallows
CC/Cc= curly tail cc= straight tail --- pipe cleaners
LL/Ll= 3 pairs legs ll= 2pairs of legs - --toothpicks
BB/Bb= blue nose bb=green nose--- push pins
GG/Gg= green feet gg=black feet ---- gum drops
EE/Ee = 2 eyes ee= 3 eyes -----map pins
Step 3-. 14 allele sacks are displayed on a table. The sacks contain slips of paper with capital and lower case
letters on them. (Remember that capital means dominant and lower means recessive.) Sacks on the right are
"mom" bags and those on the left are "dad" bags. Pull one slip from each bag and record the results. Place the
slips back into the bags/envelops. Continue to pull from each pair of bags that represent the seven traits listed
below.
Step 4. Gather materials from supply table to build your "baby bug"
Step 5. Compare and record other bugs. What do you notice?
Scientific Explanation: Lesson emphasizes how diversity of a species occurs and examines the specific traits
within a population. You can calculate the ratio of offspring and predict % of possible future generations.
Assessment: Lab analysis and review sheet will require students to assess the roles of chance and dominant
and recessive traits in the final outcome in establishing biodiversity in organisms.
Missouri Science Standards (GLE’s):
Strand 3: Characteristics and Interactions of Living Organisms
2. Living organisms carry out life processes in order to survive
B. All living organisms have genetic material (DNA) that carries hereditary information
E. Protein structure and function are coded by the DNA (Deoxyribonucleic acid) molecule
B. All living organisms have genetic material (DNA) that carries hereditary information
Kansas Science Standards:
Benchmark 1: The student will demonstrate an understanding of the structure and function of the cell.
3. Understands cells function and replicate as a result of information stored in DNA and RNA
molecules.