Background:Materials:Method:Marshmallow Meiosis with RebopsBackground:This activity could be used as an introduction to genetics, or just as easily as a summary where students can usethe vocabulary they have learned. Rebops are imaginary organisms that are prolific yet require minimum care. Students will sort the parental chromosomes, select new offspring chromosome, decode the new chromosomes and construct the baby Rebops. Meiosis, fertilization, development and birth – all in one class!Materials:- 1 bag of large white marshmallows- 1 bag of small coloured marshmallows - handful of small nails- 1 container of push pins (red and blue)- 1 container of thumb tacks- 30 pipe cleaners (cut in half)- 1 box of toothpicks- 30 sheets of construction paper (2 different colours)- 15 medium sized envelopesMethod:Before the activity:1. Two adult Rebops need to be assembled2. Make the chromosomes. Make each pair different lengths where the longest should be about 15 cm x 2.5 cm and the shortest 3 cm x 2.5 cm so that each successive pair is about 2 cm shorter than the last. Use one colour of construction paper for mom’s and the other for dad’s3. Place a full set of mom and dad chromosomes in an envelope for each group of students (groups of 2-3 are good). Each envelope should have 28 pieces of paper4. Prepare a genotype/phenotype chart (see below). An overhead transparency works well in a small room.Handouts could also be given out.In the classroom:1. Introduce the adult Rebops. Ask the students to comment on their characteristics (i.e., they look identical).2. Divide students into small groups (2-3 in each group). Hand out the envelopes containing the copies of the adults’ chromosomes. Students should then set out the 2 parental sets of chromosomes with same lengths together and letters facing down3. Next, ask the students to take 1 chromosome of each length from each parent and place them together in a new “baby” piles4. The baby’s characteristics are determined by turning over the chromosomes and encoding them according to the genotype/phenotype chart. You may ask them to write down the genotype and phenotype5. One student from each group can then come and get the materials needed to make their baby Rebop. When completed, all the baby Rebops could go into a designated “nursery” area. Have the students study all the offspring and note any differences6. You may wish to have a baby Rebop that has extra or missing parts (e.g., legs). You could lead in to discussing on the importance of complete sets of chromosomes7. If time allows get 2 groups to pair up and have their new respective Rebops mate. They grow up fast; after all you just witnessed meiosis, fertilization, development and birth in the last 45 minutes or so.What’s Happening?The sorting of the individual chromosomes, which is followed by taking one chromosome from each parent, represents meiosis. Pairing the new chromosomes to make the baby is fertilization. Development and birth happens when the students make their baby Rebops.Rebops can be used with a wide range of age groups. The simple concept of generation could be introduced with younger students. With older students you could quiz them at any stage and ask what is happening or introduce concepts like linkage and multiple alleles.Genotype/phenotype for RebopsGenotype PhenotypeAA 2 antennaeAa 1 antennaaa No antennaMM 3 green humpsMm 2 green humpsmm 1 green humpQQ Red noseQq Orange noseqq Yellow noseTT or Tt Curly tailtt Straight tailEE or Ee 2 eyesee 3 eyesLL or Ll Blue legsll Red legsDD or Dd 3 body segmentsdd 2 body