Download “Genetics Practice Quiz: Crosses and Pedigrees” 1) Define the

“Genetics Practice Quiz: Crosses and Pedigrees”
1) Define the following terms.
a) Allele
b) Gene
c) Homozygous
d) Heterozygous
e) Genotype
f) Zygote
g) Phenotype
h) Dominant
i) Recessive
2) Polydactylous cats have more than five toes. The polydactyl allele is dominant over the allele for five toes
and fingers. Calculate the genotypic and phenotypic ratio from mating between a heterozygous
polydactylous and homozygous cat with five toes and fingers.
3) The pedigree to the right traces the inheritance of a very
rare biochemical disorder in humans. Affected individuals
are indicated by filled-in circles and squares. Is the allele
for this disorder dominant or recessive? What genotypes
are possible for the individuals marked 1, 2, and 3.
4) In tomatoes, red fruit (R) is dominant over yellow fruit (r). A plant that is homozygous for red fruit is
crossed with a plant that has yellow fruit. What would be the genotypes and phenotypes of the P 1 and F1
generations? If two of the F1 generation from the above cross were mated, what would be the genotypes
and phenotypes of the F2?
5) The accompanying pedigree was obtained for a rare
kidney disease.
a) Analyze the pedigree to determine if the shaded
individuals who have kidney disease are dominant or
recessive.
b) If individuals 1 and 2 marry, what is the probability
that their first child will have the kidney disease?
6) Draw two sex cells (gametes) containing alleles for five different traits. For the same traits draw a somatic
(body) cell with the alleles labeled with the alleles in the nucleus assuming the sex cells have joined to
form an offspring.
7) Describe the pattern by which genes for separate traits are inherited. Can some genes for different traits be
linked or always inherited together? For example could the gene for hemophilia and AB Blood type be
linked or always inherited together? Why or why not?
8) Explain the connection between meiosis and inheritance.
9) The gametes of a plant of genotype SsYy should have the genotypes…
10) Following a SsYy x SsYy cross, what fraction of the offspring are predicted to have a genotype that is
heterozygous for both characteristics.
11) Cross a pea plant that is heterozygous for purple flowers and heterozygous for yellow seeds with a plant
that is homozygous recessive for white flowers and homozygous recessive for green seeds. Calculate the
phenotypic ratio of the offspring.
Inheritance Type
Mendelian
(simple or complete
dominant/recessive
relationship)
Incomplete
Dominance
Codominance
Sex-Linked
Polygenics
Multiple Alleles
Definition
Example or Cross