REEBOPS – A Marshmallow Meiosis Assignment
Purpose:

To review the concept of meiosis and its role in genetic variation of
the species
Background:
 Answer the following questions:
1. Where does meiosis occur in the human body?
2. What is the difference between haploid and
diploid?
3. What are homologous chromosomes?
Some genetics terms you should know:

Heredity:

Genes:

Allele:

Homozygous:

Heterozygous:

Genotype:

Phenotype:
REEBOP Phenotypes:
AA = 2 antenna
Aa = 1 antenna
aa = no antenna
NN = pink nose
Nn = orange nose
nn = yellow nose
HH = 1 green hump
Hh = 2 green humps
hh = 3 green humps
TT or Tt = curly tail DD or Dd = 3 body segments
tt = straight tail
dd = 2 body segments
EE or Ee = 2 eyes
ee = 3 eyes
LL or Ll = blue legs
ll = red legs
XX = female
XY = male
Materials/Procedure:
1. Obtain an envelope of REEBOB chromosomes from your teacher. You
will receive either pink or blue chromosomes.
2. There will be 16 chromosomes in each envelope. Arrange them in
homologous pairs according to length with the markings facing up.
 What is the diploid number of your REEBOP?
 What is the haploid number of your REEBOP?
3. The CHROMOSOMES are marked with various letters. The letters
represent different genetic traits (eg. AA, Hh, Dd). The letters are a
description of the genes that your REEBOP is carrying and are
referred to as the genotype.
 What is the genotype of your REEBOP?
4. A genotype determines what characteristics an organism has. Use the
code to figure out what the phenotype (observable characteristics) of
your REEBOP is.
 Number of antennae?
 Number of green humps?
 Nose colour?
 Type of tail?
 Leg colour?
 Number of eyes?
 Number of body segments?
 Sex?
5. Your REEBOP is a very frisky creature. It likes to reproduce every
semester. Find a person in class who has a set of chromosomes for a
REEBOP of the opposite sex.
6. Lay both your sets of chromosomes on the table with the markings
face down and arrange them in homologous pairs to length (Longest to
shortest).
7. Select one chromosome from each length and turn it right side up
(one from the female REEBOP and one from the male). Put the other
chromosomes away for now.
 What is the genotype of your offspring REEBOP?
 What is the phenotype of your offspring REEBOP?
o Number of antennae?
o Number of green humps?
o Nose colour?
o Type of tail?
o Leg colour?
o Number of eyes?
o Number of body segments?
o Sex?
8. Once you have determined your REEBOP’s phenotype, get the
necessary materials and make your REEBOP.
9. On a blank piece of paper, write your REEBOP’s genotype and its name.
Place it at the back of the class (but don’t put your chromosomes away yet).
Discussion Questions:
1. After you have “produced” your offspring REEBOP, write down the
genotypes for another three future children. Are the chromosome
combinations ever the same? What does this mean to a species in
general? (now you can put your chromosomes away)
2. What would happen if each parent did not contribute the same amount
of genetic information to each child?
3. Compare your offspring to its parents. Describe the similarities and
differences.
4. Looking at the other REEBOPS, what is the fraction of REEBOPS that
have 3 body segments? 2 body segments? Convert these numbers to
decimals.
5. What fraction of the REEBOPS have 2 eyes? 3 eyes? Convert these
numbers to decimals.
6. What fraction of the REEBOPS are female? Male? Convert these
numbers to decimals.