Two ants are heterozygous for pointed
heads. Describe their offspring if a round
head is recessive.
In the fruit fly, red eyes are dominant to white eyes. If you
had a red-eyed fly, how would you determine if it was
homozygous red or heterozygous red?
Hemophilia is a sex-linked, recessive trait in
humans, carried on the X chromosome. A
hemophilic man and a heterozygous
woman have a son, what is his chance of
being a hemophiliac?
What is a clue that incomplete dominance may be
involved in a particular trait? Provide an example.
If two plants of the genotype TT and tt were
crossed, what would be the results of the
F2 generation?
In fruit flies, sepia eye colour is recessive to the dominant
red eye colour, and curved wings are recessive to the
dominant straight wings. If a double heterozygous parent
is crossed with a fly which is heterozygous for eye colour
but has curved wings, what would be the phenotype ratios
in their offspring?
The rhesus factor (+/-) is carried on a
separate chromosome than the ABO gene
and Rh+ is dominant to Rh-. Allan has
blood type AB/Rh-, and his wife Kate has
blood type A/Rh+. If Kate is heterozygous
for both genes, what are the possible blood
types in their children, and what chance do
they have for each type?
A man with type AB blood is married to a woman also with
type AB blood. What blood types will their children have
and in what proportion?
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?
What is the probability that a male will inherit an X-linked
recessive allele from his father?
In cattle when a (RR) red bull is crossed
with a (rr) white cow, the heterozygous
offspring (Rr) are neither red nor white but
roan (red and white hair). Determine the
phenotypic and genotypic percentages for
the offspring from a cross between a roan
bull and a red cow
A man and a woman both have normal vision. They have
three offspring, all of whom marry people with normal
vision. The three offspring and their children are as
follows:
a) A son with red-green colour blindness who has a
daughter with normal vision
b) A daughter who has three sons with normal vision
c) A daughter who has one red-green colour blind son and
one son with normal vision
Draw the pedigree for this family, indicating the affected
people and the carriers.
In horses, black colour (B) is due to a
dominant allele and chestnut colour (b) is
due to its recessive allele. A pacing gate
(T) is dominant over a trotting gait (t). A
heterozygous black pacer is crossed with a
chestnut trotter. What are the possible
genotypic and phenotypic ratios of the F1
generation?
A woman is red-green color-blind. What can
we conclude, if anything, about her father?
Future children when the father has normal
vision?
Two couples had baby boys in the same hospital at the
same time. There was a mix-up in the hospital nursery.
Using the information given in the table below, explain
which baby belongs to which family. Be sure to include
Punnett squares in your answer.
Parent Parent Parent Parent Baby Baby
1
1
2
2
1
2
Blood
B
AB
B
A
A
O
Type
Use the following words to complete the blanks: negative,
positive, antigens, antibodies
Persons with Rh ____________ blood have Rh
____________ but don’t have any plasma ____________
.