Download Name Date ______ Lab: Sexually Reproducing Organisms (Meiosis

Name ___________________________________________________________ Date ______
Lab: Sexually Reproducing Organisms (Meiosis and Sexual Reproduction)
Introduction:
Reebops are bizarre, sexually reproducing organisms that are known to inhabit biology labs.
They are rarely seen in the wild as they are extremely fast. Once you have a male and female
in captivity, your room will soon be filled with Reebops. They are very prolific and require
minimal care. My Reebops live quite comfortably in a covered shoebox with small holes
punched in the sides for ventilation.
This species is ideal for studying traits that pass from one generation to the next. They have a
short life span (two lab periods), reproduce in fairly large numbers, are cheap to raise, and have
a number of easily identified traits.
Purpose: How can genetic variation in sexually reproducing organisms be modeled?
Materials:
Pipe cleaner
Toothpicks
thumbtacks and T-Pins
parent chromosomes
colored mini-marshmallows
large white marshmallows
Part I
1. Each group will receive one set of each parent’s chromosomes.
2. Orange chromosomes are from the mother and green are from the father
3. Cut the chromosomes out of the sheets and place them in front of you, letter side down.
What is the most obvious way of identifying the chromosomes?
If these were pictures of human chromosomes, how many would there be? __________
In human males, one set of chromosomes don’t match. This is the twenty-third or sex
chromosomes. In females they match. Which human parent determines the sex of the
child?
4. What is the name of the process by which human chromosomes are separated and
identified?
Part II
5. Pick one chromosome from each of the mother’s pairs and separate it from the other
chromosomes. These are the “picked” chromosomes. Do the same for the father’s
chromosomes.
What part of sexual reproduction does this action represent?
6. Place the “picked” chromosomes from the mother and add them to the pile of “picked”
chromosomes from the father. What part of sexual reproduction does this action
represent?
7. Match the mother’s and father’s chromosomes by size. Turn them over and record the
results on the Reebop Gene Data Table.
8. Fill in the rest of the table with phenotype, parts needed, and number of parts needed.
9. Using your completed table, gather together all the parts you will need to build your baby
Reebop.
** Do not eat any part of your baby Reebop. **
10. Construct your baby Reebop. Once you’ve finished, select a name for your baby and
write it on a sheet of paper, along with your name and your partner’s name.
11. Describe the characteristics of your baby Reebop.
12. Make a drawing of your baby in the space provided. Label the parts that the alleles code
for. Include its name.
Analyze:
13. Good Reebop parents raise young in a nursery. The nursery is on the lab counter in the
back of the lab. Place your baby on your identification sheet in the nursery area.
14. Compare your offspring with the other newborns. Are any two alike?
15. Why are there differences in the babies?
16. What would it take to make two newborns identical?
17. Why would brothers and sisters be similar?
18. Which trait(s) in Reebops appears to blend and show incomplete dominance? Why do
you think so?
19. Which trait(s) in Reebops appears to be codominant? Why do you think so?
Conclusion:
(Remember: Multiple paragraphs. Restate the question in your response. Double space,
12-point font. When possible, refer to your Reebop baby to substantiate your
conclusion.)
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Describe what happens to chromosomes when they go through replication, synapsis,
and disjunction.
Explain why brothers and sisters are not identical even though they come from the same
parents. Use two of Mendel’s laws to explain your answer.
What is the difference between a gene and a chromosome?
How is a dominant trait different from a recessive one?
How is incomplete dominance different from dominant/recessive?
What is nondisjuction?
What are the genetic results when nondisjunction occurs? Describe one specific
example of nondisjunction in humans.
Reebop Genetic Decoder:
Alleles:
A = 2 antenna
HO = orange back humps (1 for each allele)
a = 0 antenna
HP = pink back humps (1 for each allele)
HO HP = 1 orange & 1 pink back hump
Q = green nose
q= yellow nose
E = 2 eyes
e = 3 eyes
L = 4 red legs
l = 4 blue legs
TC = curly tail
TS = straight tail
TC TS = wavy tail
D = 3 body segments
d = 2 body segments
The color of the parent chromosomes: Mother’s chromosomes: orange Father’s chromosomes: green
Reebop Gene Data Table
Allele
Pair
1
2
3
4
5
6
7
Genotype
Phenotype
Part Needed
# of Parts Needed
Name ___________________________________________________________ Date ______
Lab: Sexually Reproducing Organisms (Meiosis and Sexual Reproduction)
Grade Sheet
Points
Your Points
Part I
4
________
Part II
4
________
Data Table
14
________
Drawing
10
________
Relatedness of terminology
8
________
Construction
10
________
Analyze
12
________
Conclude
28
________
Neatness
10
________
Total
100
________