Practice Test
SIMPLE GENETICS PRACTICE PROBLEMS
1) For each genotype below, Label as heterozygous (He) or homozygous dominant (HD) or homozygous recessive (HR)
AA _____ Ee ____ Ii _____ Mm _____
Bb _____
Cc _____ ff ____
Gg ____
Jj _____ kk _____ nn _____ oo _____
DD _____ HH ____ LL _____ Pp _____
2) For each of the genotypes below determine what phenotypes would be possible. a. Purple flowers are dominant to white flowers.
PP __________________ Pp __________________ pp __________________ b. Bobtails in cats are recessive to normal length tails
TT _________________ Tt _________________ tt _________________
3) For each phenotype below, list the genotypes (remember to use the letter of the dominant trait)
a. Straight hair is dominant to curly.
____ straight ____ straight ____ curly
b. Pointed heads are dominant to round heads.
_____ pointed _____ pointed _____ round
c. Right handedness is dominate to left handedness
_____ right _____ right _____ left
4) Set up the Punnet squares for each of the crosses listed below. Round seeds are dominant to wrinkled seeds
RR x rr
RR x Rr
How many of the offspring will be:
Round? Genotypes:
Wrinkled?
How many of the offspring will be:
Round? Genotypes:
Wrinkled?
Rr x Rr
Rr x rr
How many of the offspring will be:
Round? Genotypes:
Wrinkled?
How many of the offspring will be:
Round? Genotypes:
Wrinkled?
PRACTICE WITH CROSSES.
5a) A TT (tall) plant is crossed with a tt (short plant).
What percentage of the offspring will be tall? ___________
5b) A Tt plant is crossed with a Tt plant.
What percentage of the offspring will be short? ______
In guinea pigs, the allele for short hair is dominant.

6) What genotype would a heterozygous short haired guinea pig have? _______
What genotype would a pure breeding short haired guinea pig have? _______
What genotype would a long haired guinea pig have? ________
7) Two short haired guinea pigs are mated several times. Out of 100 offspring, 25 of them have long hair.
What are the probable genotypes of the parents? ________ x ___________
Incomplete Dominance
9) Practice writing genotypes for the phenotypes listed in each set. Remember that the "medium" trait must always be heterozygous a) Birds can be blue, white, or white with blue-tipped feathers. (Blue is dominant) b) Flowers can be white, pink, or red. (Red is dominant) c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked (Curly is dominant)
10) In humans, curly hair is dominant over straight hair.
Cross a woman heterozygous for hair curl with a man with straight hair.
What are the phenotype & genotype ratios of their offspring?
11) In four o'clock flowers red is dominant to white, Cross a red plant and a white plant
12) Cross any 2 of their offspring
What are the genotype and phenotype ratios?
CO-DOMINANCE AND BLOOD TYPES
Blood Type is controlled by 3 alleles: A, B, O. A & B are codominant, O is recessive.
The Letter I represents the blood cell, and the allele is a superscript
Dominant
I A = A protein I B = B protein
Recessive i = no protein
13) Write the genotypes:
a) What are the two genotypes possible for a person who as A blood? ______________
b) What genotype does a person with AB blood have? _______________
c) What genotype does a person with O blood have? ____________
d)What are the two genotypes possible for a person who as B blood? ______________
14) A man with type AB blood is married to a woman also with type AB blood. What blood types will their children have?

15) A man with type AB blood is married to a woman with type O blood. They have two natural children and one adopted child. Jane has type A blood, Bobby has type B blood, and Grace has type O blood.
Which child was adopted? ____________________
16) A woman with type A blood (genotype AO) is married to a type B person (genotype BO). What percent of their children will have:
A blood? _______ B blood? _______
17) Three babies get mixed up in the hospital:
Baby #1 has type O blood. Baby #2 has type A blood. Baby #3 has AB blood.
Using the parents’ blood types below, determine which baby belongs to which of the parents.
The Washingtons
MOM: O
The Lincolns
MOM: AB
The Kennedys
MOM: B(Hetero)
DAD: A
Baby# _____
Sex-Linked Traits
DAD: B
Baby # _____
DAD: B
Baby # _____
18) In humans, hemophilia is a sex linked trait. Females can be normal, carriers, or have the disease. Males will either have the disease or not (but they won’t ever be carriers)
X H X H = female, normal
X H X h = female, carrier
X h X h = female, hemophiliac
X H Y = male, normal
X h Y = male, hemophiliac
A woman who has hemophilia marries a normal man.
How many of their children will have hemophilia, and what is their sex?
19) In cats, the gene for calico (multicolored) cats is codominant. Females that receive a B and an R gene have black and orange splotches on white coats. Males can only be black or orange, but never calico. Here’s what a calico female’s genotype would look like. X B X R
Show the cross of a female calico cat with a black male.
What percentage of the kittens will be black and male? _________
What percentage of the kittens will be calico and male? _________
What percentage of the kittens will be calico and female? _________
If there are 24 kittens born, how many would you expect of each phenotype? Show your math.

Human Pedigrees
20) What is the symbol for female?
21) What is the symbol for male?
22) What does it mean when the symbol is shaded?
23) CREATE THE FOLLOWING PEDIGREE to track the inheritance of being able to roll your tongue
A Dave and Marla woman get married. Dave can roll his tongue, but Marla can’t. They have two girls (Mary and Marge) that can both roll their tongues.
Dave has two sisters; Tanya can roll her tongue, but Joan can’t. Both of his parents can roll their tongues.
Marla has three brothers: two of them (Joe and Cliff) can roll their tongues, but Thomas can’t. Her mother can’t roll her tongue, but her father can.
Mary and Marge get married and have kids of their own. Mary married Bob, who can roll his tongue, and has twin sons who can’t roll their tongues. Marge marries Jeff, who can’t roll his tongue. They have two tongue rolling girls and a son that can’t. a) Label each generation and individual b) Label each individual with the corresponding genotype c) Can you tell what the genotypes are for Dave and Tanya? Why or why not? d) Identify the inheritance pattern: Is it Dominant or Recessive AND is it Sex-Linked or Autosomal?