How similar are traits of offspring to those of their parents?
Part A. Determining Parent Phenotypes
Names:
1. Examine the models of 8 chromosomes on the chromosome sheet. Four of the chromosomes are from the Mother and four
are from the Father. Chromosomes of equal length & color are to be considered homologs or homologous chromosomes.
The "Mother" originally got her chromosomes from her parents (1 of each chromosome from her mom and 1 of each
chromosome from her dad). The same is true for the "Father."
2. Use a pair of scissors to cut out the 8 chromosomes. OR (drag & drop) them into a new document. Manipulate the page
sizes so you may toggle between pages on the same screen.
3. Make sure that the homologs are next to each other. For example with the mother, the 2 long pink chromosomes should be
side by side, and the 2 short pink ones should be side by side. Do the same for the "Father's" blue chromosomes.
4. To determine the phenotypes, or physical characteristics, that are passed on, we need to look at homologous chromosomes
to find the alleles that make up the genotype, or type of genes.
5. The letters written on each chromosome stand for alleles of the same gene. Examine Table 1 below. It shows what traits
are represented by the letters.
6. Complete Table 2 for the phenotypes of both the mother and father. Describe the nine different phenotypes for each parent
based on the alleles present on their chromosomes. Long chromosomes have the first 5 traits, short have the last 4 traits.
TABLE 1
Allele
F
B
G
E
R
T
H
D
C
Phenotype
six fingers
black hair
gap between front teeth
free or detached earlobes
Rh positive blood
can roll tongue
mid-digital hair
skeleton of average height
presence of Huntington’s disease
Allele
f
b
g
e
r
t
h
d
c
Phenotype
five fingers
blonde hair
no gap between front teeth
attached earlobes
Rh negative blood
cannot roll tongue
no mid-digital hair
skeleton development- dwarfism
absence of Huntington’s disease
Part B: Determining Children's Phenotypes
1. Place the 4 Mother chromosomes face down on the right side of your desk. Or at the top of a new page.
2. Place the 4 Father chromosomes face down on the left side of your desk. Or at the bottom of a new page.
3. RANDOMLY pick 1 long chromosome from the father's pile and 1 long chromosome from the mother's pile. Then pick 1
short chromosome from each parent’s pile. This simulates chromosomes that are passed to the 1st child during fertilization.
4. Turn the chromosomes over. Read the allele combinations for the 1st child and decide which phenotypes they correspond
to. Record the genotypes and phenotypes for the 1st child in table 2, labelled 1st child.
5. Repeat steps 1-4 two more times to simulate the chromosomes passed to a 2nd and 3rd child.
6. Draw a picture of your family. : o) and complete the questions and conclusions section on the answer sheet.
Chromosome Sheet:
Work Space to Drag and Drop Below...or work on a new page.
Mother’s Chromosomes
Father’s Chromosomes
F
f
t
t
b
b
h
h
H
H
f
G
e
eR
b
f
g
g
B
E
Er
g
g
e
e
R
D
c
T
h
h
d
c
t
H
g
g
e
e
r
D
C
d
c
Lab Investigation Answer Sheet
Name:
for online submission: only submit this page with its answers.
Table 2
Trait
Father
Mother
phenotypes
phenotypes
1st child
genotype
phenotype
2nd child
genotype
phenotype
3rd child
genotype
phenotype
# of fingers
(6/5)
hair
(black/blonde)
gap in teeth
(y/n)
earlobes
(free/attached)
Rh type
(+/-)
tongue roll
(y/n)
mid-digit hair
(y/n)
height
(norm/dwarf)
Huntington’s
(y/n)
Questions:
1. In this simulation, how many chromosomes did each child receive from each parent? (**)
2. In humans, how many chromosomes would a child normally get from each parent? (**)
3. Explain how the element of chance enters into the inheritance of traits. (Hint: Mendelian Laws)
(**)
4. Using data you generated for the 1st child, determine the number of physical characteristics inherited from only the father
(**) or from only the mother (**).
5. Using data you generated for the 2nd child, determine the number of physical characteristics inherited from only the father
(**), the mother only (**), and the number of traits in common with the 1st child (**).
6. Using data you generated for the 3rd child, determine the number of physical characteristics inherited from only the father
(**), the mother only (**), the number of traits in common with the 1st child (**), and the number of traits in common with
the 2nd child (**).
Conclusion Essay:
How similar are traits of each offspring to those of their parents and each other? In other words, compare and contrast each
child to each other and to their parents. (**)