Reebops:
a “model” organism for learning
genetics
Do Now:
Define the following OR
draw a picture of each term
Gene
 Allele
 Genotype vs. Phenotype
 Heterozygous vs. Homozygous
 Dominant vs. Recessive

Objectives
SWBAT explain that sexual
reproduction produces offspring that
inherit half their DNA from each
parent.
 SWBAT explain how genes are
carried from parents to their
offspring on chromosomes

What are Reebops?
Reebops are
imaginary animals
made from
marshmallows and
other easily found
materials
 You and your partner
will be making a baby
Reebop

Chromosomes in Humans
Why do chromosomes come in pairs????
Because humans
reproduce through
sexual reproduction,
they inherit half or
50% of their DNA
from each parent.
 SO, they inherit 23
chromosomes from
each parent.

What does a human baby
look like?

Because
chromosomes
carry genes, when
MOM’
the two sex cells
S
meet and the
chromosomes
form pairs--the
baby ends up with
2 alleles for each
trait.
DAD’S
Parent Reebops

Record phenotyppic observations of
parent reebops on your paper
How to construct your baby
Reebop?
You will be given 7
sets of chromosomes
in envelopes.
2. Turn the
chromosomes face
down on the desks so
no letters are
showing.
3. Sort them so that
they are matched by
length.
1.
Chromosome Pairs
The pink pair of
strips are the
mother’s
chromosomes.
 The blue pair of
strips are the
father’s
chromosomes.
 Each individual
strip is an allele.

Take 1 strip from the
mother and 1 strip from
the father.
5. Make a new pile for your
Reebop baby.
6. Repeat for the rest of
the strips.
4.
The baby
Reebop’s alleles 
Congratulations!! It’s a… Reebop

Return the
remaining alleles to
the envelopes.
8. Turn over your
chromosomes to
see what your baby
will look like.
7.
Each Reebop baby
will have 14
chromosomes: 7
blue and 7 pink.
Reebop Worksheet
9.
10.
11.
12.
13.
Fill out the genotype and phenotype for
your baby.
Highlight each of your baby’s 7 traits
in the “Key to Reebop Traits.”
BUILD YOUR BABY REEBOP using the
materials in the ziplock bags
Draw your Reebop baby and one of your
classmates
Answer the Post-Lab Questions
You just conducted a
Reebop breeding program.

What were some of the observable
differences between the parent Reebops
and their babies?

What were some of the
observable differences
between the babies?

In other words, how did the
phenotypes of the Reebops differ?
How did the phenotypes of
the Reebops differ?
Antennae
 Tails
 Body segments
 Humps
 Eyes
 Legs
 Noses

Quick-Think Time
Think–Pair–Share
 How did the Reebop babies end up
being different from their parents
and
from each other?
Sources of Variation:

Each Reebop parent has two copies of each
chromosome in all of its body cells.

A cell with two sets of chromosomes is
diploid.

Traits are determined by genes carried on
chromosomes.

Different forms of a gene for the same trait
are called alleles.

Both copies of a chromosome might carry
the same allele or they might carry different
alleles.