Additional Genetics Problems
Name ___________________________________
1. Simple Dominant/recessive
B = black fur
b = tan fur
Homozygous dominant: g: _____ ph: ______________
Homozygous recessive: g: _____ ph: ______________
Heterozygous:
g: _____ ph: ______________
In the space at the right, cross a tan male with a heterozygous female.
What phenotypes are possible in the offspring and what are their probabilities?
2. Incomplete Dominance
R = red flowers R’ = white flowers
Homozygous red:
g: _____ ph: ______________
Homozygous white:
g: _____ ph: ______________
Heterozygous:
g: _____ ph: ______________
In the space to the right, cross two heterozygous flowers.
What phenotypes are possible in the offspring and what are their probabilities?
3. Co-Dominance
N = normal shaped RBCs
S = sickled RBCs
Homozygous normal:
g: _____ ph: ______________
Homozygous sickled:
g: _____ ph: ______________
Heterozygous:
g: _____ ph: ______________
In the space to the right, cross two heterozygous individuals.
What phenotypes are possible in the offspring and what are their probabilities?
4. Sex-Linked Inheritance
H = normal blood clotting
Females:
h = cannot clot blood
Homozygous dominant g: _____ ph: ______________
Homozygous recesive g: _____ ph: ______________
Heterozygous
Males:
g: _____ ph: ______________
Phenotypes:
Has the disease
g: _____
Normal blood clotting g: _____
In the space at the right, cross a diseased male with a female who is a carrier.
What are the phenotypes possible among girl offspring and their probabilities?
What are the phenotypes possible among boy offspring and their probabilities?
5. Multiple Alleles:
Fill in the table:
Phenotype
Genotypes
Possible:
Type A
Type B
Type AB
Type O
In the space at the right, cross a type O parent with a type AB parent.
What phenotypes and their probabilities are possible in the offspring?
Human Genetics Disorders.
Use your text (Ch. 12) or notes to complete the table about the following human
genetic disorders.
Genetic Disorder
How it’s inherited
(autosomal
dominant/recessive; or
sex-linked)
Symptoms
Other
(treatable?, frequency?)
Huntington’s Disease
Tay-Sachs
PKU =
____________________
Cystic Fibrosis
Sickle-Cell Disease
Hemophilia
Try this whooper dihybrid cross on a separate sheet of paper:
Woman: carrier for red-green colorblindness and type O blood
Man:
is red-green colorblind and is heterozygous for type A blood.
g: ___________________
g: ___________________