2. Other Patterns of Inheritance Practice Problems
H.W. Finish:
Patterns of Inheritance (Gene
interaction) Practice Problems
Answer the following questions(in complete sentences) on a separate
sheet of paper. Show your work for full
credit.
1.
Albinism is
a rare recessively inherited disorder (a). Those who suffer from this
disease don't produce melanin (a skin pigment). Consequently, albinos
have white hair, pale skin and pink eyes.
a.
What is the
probability that an albino man will have an albino child with a woman who is
normally pigmented, but whose mother is an albino?
b.
What is the
pattern of inheritance for albinism (incomplete, complete, or co-dominance)?
2.
When red
snapdragons (R) are crossed with white snapdragons (r) the resulting flowers
are pink.
a.
What is the
pattern of inheritance for flower color (incomplete, complete, or co-dominance)
b.
Complete a
Punnett square to show the cross between two pink snapdragons.
c.
What are the
genotypic and phenotypic ratios for the above Punnett square?
3.
A
black chicken marries a white chicken. All of their chicks are speckled
black and white.
a.
What is the
pattern of inheritance for feather color (incomplete, complete, or
co-dominance)?
b.
How is this
different from the scenario with the snapdragons in #2?
c.
What is the
genotype of a speckled chicken?
4.
In
snapdragons tall stems are dominant (T) to short stems (t). Red (R)
is incompletely dominant to white flower (r) color, the
heterozygous condition being pink.
a.
A tall pink
plant is crossed with a short red plant. If tall is heterozygous in this case,
what will be the genotypes and phenotypes of the offspring? Hint: This is a
dihybrid cross! Show your work with a punnett square.
b.
What two patterns of inheritance are illustrated in this scenario?
5.
Attached
earlobes in humans is due to recessive gene (f) while free earlobes are
dominantly inherited (F).
a.
What is the
probability that a woman with free earlobes (whose father’s earlobes are
attached) will have a baby with attached earlobes with a man whose earlobes are
attached?
b.
What pattern
of inheritance is illustrated in this scenario?
6.
Tongue
rolling (rolling the tongue into a “taco”shape) is dominant over not having the
ability to roll the tongue (R and r- respectively). A man has free hanging
earlobes and can roll his tongue; however his mom and wife have attached
earlobes and cannot roll their tongues.
a.
Cross the
man and his wife and give the phenotypic ratio of their offspring.
b.
What pattern
of inheritance is illustrated in this scenario?
