Name _________________________________ Date _______________ Period ________
Lesson 65 – Critter Breeding Packet
Ocean’s Alleles
Offspring’s Genes
Heads
Tails
From Ocean
1. Body
Segments
B
2. Legs
Trait
Offspring’s
Phenotype
Lucy’s Alleles
Heads
Tails
b
B
b
L
l
L
l
3. Eyes
E
e
E
e
4. Nose
N
n
N
n
5. Tail Color
T
t
T
t
6. Tail Style
S
s
S
s
7. Antennas
A
a
A
a
8. Spikes
G
H
G
H
Ocean’s Sex
Chromosomes
9. Sex
Heads
Tails
X
Y
From Lucy
Offspring’s
Genotype
Offspring’s Sex
Chromosomes
From Ocean
From Lucy
Offspring’s
Genotype
(Use Critter Code to
fill this in)
Offspring’s
Phenotype
Lucy’s Sex
Chromosomes
Heads
Tails
X
X
Critter Portrait
Draw a picture of your critter, color all traits.
Offspring Analysis
Trait
1. Body Segments
2. Legs
3. Eyes
4. Nose
5. Tail Color
6. Tail Style
7. Antennas
Dominant
3 Segments
Blue
Two
Long
Blue
Curly
Two
8. Spikes
1 Short Blue
9. Sex
Male
Medium
2 Long Green
Recessive
2 Segments
Red
Three
Short
Orange
Straight
One
1 Short Blue + 2 Long
Green
Female
Analysis Questions
1. Compare the similarities and differences between the critters (all siblings!) made by your classmates.
There are more critters with the dominant traits above in table (3 body segments, blue legs, two eyes
etc…)__than the recessive traits___________________________________
2. List the characteristics that show a simple dominant/recessive pattern (like tail color). Indicate which trait is
dominant and which is recessive by underlining the dominant trait.
See chart above – everything except nose, spikes and sex will show 3:1 dominance pattern of inheritance
Some traits do not show a simple dominant vs. recessive pattern. For example, in some plants, a cross
between a red- and white-flowered plant will give pink-flowered offspring. This is called incomplete
dominance. A different example is human blood type. A person with Type A blood and a person with
Type B blood can have a child with type AB blood. This is called co-dominance, as both traits appear in
the offspring.
3. For which characteristics do some offspring have traits in between Skye’s and Poppy’s traits? Explain which kind
of dominance this is.
_________Nose length is an example of incomplete dominance – medium is in between long and short
and that is the phenotype when heterozygous (Nn) for nose ____________________________
4. For which characteristic(s) do some offspring have both Skye’s and Poppy’s traits? Explain which kind of
dominance this is.
______Spikes is an example of co-dominance and you see both traits (short blue and long green) when
heterozygous (GH) for spikes
5. Which critter trait is affected by an environmental factor, such as light, temperature, or diet? Explain.
Tail style if you have the Ss genotype is affected by diet (critric acid) - _ _
6. Consider the pattern for sex determination.
a. How is a critter’s sex determined?
XX is a female and XY is a male_and we determined sex of our critter in class with a toss of the coin for
Ocean’s genetic contribution for sex.
b. Whose genetic contribution—Ocean’s or Lucy’s—determines the sex of the offspring?
Ocean is the male and he contributes either an X chromosome or a Y chromosome to determine sex of the
offspring.
7. Who does your critter most look like –Skye, Poppy, Ocean, or Lucy? On which traits did you base your choice?
____________________answers vary
8. Draw a critter with all recessive traits. Assume the recessive trait for spikes is no spikes.