Download Zork Inheritance Simulation

Introduction
A long time ago, in a galaxy far, far away, a great race of beings lived on a planet called ZORK. The
inhabitants were known as Zorkonians. They are made up of 10 basic genes (unit) that code for their
appearance. Each one of these genes has different alleles (versions of a gene). With this in mind, there
are 1,024 different possible combinations for their appearance! This is called their phenotype or their
physical appearance. If we look at their genes, there are 59,049 different combinations of the alleles!
This is called the genotype or genetic makeup. Letters are used to represent the alleles that control the
genes and one letter or allele is inherited from each parent. Since meiosis splits up pairs (homologous)
of chromosomes, each parent passes on one copy of each gene. Consequently an
individual has two copies of every gene, one from mom (maternal) and one from dad
(paternal). The genotype or combination of alleles for an individual determines their
phenotype or traits. If an allele covers up another version of the gene, its considered dominant and
represented with a capital letter. So whenever an individual possesses a dominant allele, he or she will
have the dominant trait. Recessive represented by lower case letters, and the recessive trait is hidden
when an individual also has a dominant allele. For a given trait, if an individual has two different alleles
the genotype is heterozygous (ex. Gg, Tt, Ee, Ff). If an individual has two of the same alleles the
genotype is homozygous (ex. GG, gg, TT, tt, FF, ff).
Experimental Question: How are genes and traits passed on from parents to offspring?
Hypothesis: Make a prediction about the experimental questions. Explain the reasoning behind your prediction.
Procedure
1. Take the longest pair of one color of chromosomes (male) and the longest pair of the other color of chromosomes
(female) and place them FACE DOWN on their desks so that they cannot see the letter. (Since the strips I added are
not colored on both sides, have one student select males, and another females.)
2. WITHOUT TURNING THE CHROMOSOMES OVER, pick one chromosome of the longest size from one color, and pick
one chromosome of the longest size of the other color. Put these in the middle as one new pair.
3. Repeat steps 1-3, taking one from each pair from longest to shortest. You and your partner should end up with ten new
traits; each pair is one color chromosome and one of the other color chromosomes (strip).
4. Turn over the chromosomes that remain on your table. These represent a new "baby" zork! On the DATASHEET,
record the letter found on the first color of chromosomes in the Male Gene column. Record the letter found on the
second color of chromosomes in the Female Gene column. Be sure you copy the letters exactly, uppercase or lowercase. THIS IS IMPORTANT!
5. After filling out the DATA SHEET, return all chromosomes to their proper bags.
6. Determine the GENOTYPE by combining the 2 letters.
a. Determine if the trait is dominant or recessive.
7. Record the PHENOTYPE for each characteristic, using the KEY and TABLE from the ZORK GENETICS assignment.
Record this on the Zork Worksheet.
8. Now color and add parts to the baby zork.
Allele
T
t
G
g
E
e
F
f
H
h
L
l
W
w
N
n
R
r
B
b
Trait
Dominant/Recessive Genotype Phenotype Heterozygous Homozygous
Tall
Dominant
TT,Tt
Tall
Tt
TT
Short
Recessive
tt
Short
tt
Green
Green
Dominant
GG,Gg
Gg
GG
hair
Hair
Yellow
Yellow
Recessive
gg
gg
hair
Hair
One Eye
Dominant
EE,Ee
One Eye
Ee
EE
Three
Three
Recessive
ee
ee
Eyes
Eyes
One
Dominant
FF,Ft
One Fang
Ff
FF
Fang
Two
Two
Recessive
ff
ff
Fangs
Fangs
Two
Two
Dominant
HH,Hh
Hh
HH
Horns
Horns
One
Recessive
hh
One Horn
hh
Horn
Purple
Purple
Dominant
LL,Ll
Ll
LL
Lips
Lips
Green
Green
Recessive
ll
ll
Lips
Lips
Two
Two
Dominant
WW,Ww
Ww
WW
Wings
Wings
No
Recessive
ww
No Wings
ww
Wings
One Leg
Dominant
NN,Nn
One Leg
Nn
NN
Two
Recessive
nn
Two Legs
nn
Legs
Green
Green
Dominant
RR,Rr
Rr
RR
Skin
Skin
Yellow
Yellow
Recessive
rr
rr
Skin
Skin
Thick
Thick
Dominant
BB,Bb
Bb
BB
Eyebrow
Eyebrow
Thin
Thin
Recessive
bb
bb
Eyebrow
Eyebrow
\
Data
Male Genes in Sperm Cell
Trait
Genotype
Female Genes in Egg
Phenotype
Tall/Short (T/t’s)
Hair (G/g’s)
Eyes (E/e’s)
Fangs (F/f’s)
Horns (H/h’s)
Lips (L/l’s)
Wings (W/w’s)
Legs (N/n’s)
Skin (R/r’s)
Eyebrows (B/b’s)
(D/d’s)
Conclusions
1. Summarize the process of inheritance as modeled in the activity.
2. Compare your Zork to other Zorks around the room. Explain any similarities or differences you see.
3. Separating the chromosomes represented which process that sorts the genes into sperm and egg cell? How is the
model accurate and/or inaccurate?
4. How many copies of each gene are found in the sex cells, compared to the other cells (body cells) of the baby and adult
Zork?
5. For the bold terminology in the introduction construct a concept map, or write definition and examples of each word.
6. Can you predict the phenotype of a baby just based on the phenotype of the parents? Why or why not?
7. If a Zork has a heterozygous genotype, can you determine if the dominant or recessive trait will be expressed?
8. If a Zork has a homozygous genotype, can you determine if the dominant or recessive trait will be expressed?
Extension
In this simulation each homologous pair of chromosomes contained one gene. Consequently, each gene was inherited
separately as the chromosomes were pulled apart into different gametes by meiosis. In reality there are hundreds of genes
on each pair of homologous chromosome. Describe the process during meiosis that makes each gene inherited
independently even if they are on the same chromosome. Are genes truly inherited 100% independently? Describe an
instance where two genes may be linked or inherited together.
Chromosome Strips
For Father
T
T
g
g
E
e
F
f
h
h
L
l
W
W
N
n
R
r
B
b
Chromosome Strips
For Mother
t
t
G
G
e
e
F
f
H
H
l
l
W
w
n
n
R
r
B
b