Solved by a verified expert:1.
Suppose one gene has alleles A and a. Remember that most organisms are diploid;
i.e., they contain homologous chromosomes with identical genes, although the
alleles may be different on each homologue.
Gametes, on the other hand, are haploid, containing only one of the two
homologues, and thus only one of the two alleles.

The genotype of an organism is its genetic constitution, i.e., the
alleles present.

For each of the following diploid genotypes, indicate the possible
genotypes of the gametes.

Diploid genotype Gamete genotype (four cells are
produced)

AA _____, ______,
_____, _____

aa _____, ______,
_____, _____

Aa _____, ______, _____, _____

III.
MONOHYBRID PROBLEMS ILLUSTRATING CODOMINANCE

9.
Another type of monohybrid inheritance involves
the expression
of both phenotypes in the heterozygous
situation. This is called
codominance.

One of the best known examples of codominance occurs in the blue
Andalusian chicken. “Blue”
birds are heterozygous (BW) and result from the mating between a black bird
(BB) and a white bird (WW). Blue birds do
not really have blue feathers, instead having a mixture of black and white feathers that reflects
light to appear blue. Thus, the “blue” coloration is not a
consequence of blending of the pigments (after all, the mix is not gray) but
rather the result of both colors existing on the same bird. That is both phenotypes occur on the same
individual.

a.
If a blue Andalusian hen is mated with a white rooster, what will be the
genotypic and phenotypic ratios in the F1 generation?

Genotypic ratio ________________________________________

Phenotypic ratio _______________________________________

b.
List the parental genotypes of crosses that could produce at least some:

white offspring _______________________________

black offspring ________________________________________

11.
The sex chromosomes bear alleles for traits, just like the other
chromosomes in our bodies. Genes that
occur on the sex chromosomes are said to be sex-linked.

The Y chromosome is smaller than its homologue, the X chromosome. Consequently, some of the loci present on the
X chromosome are absent on the Y chromosome.

In humans, color vision is a sex-linked trait; the gene for color vision
is located on the X chromosome but is absent from the Y chromosome.

Normal color vision (XC) is dominant over color blindness (Xc). Suppose a color-blind manfathers children of a woman with the genotype
XCXC?

a.
What is the genotype of the father?

_________________________________________________________

b.
Would any of the daughters be color blind?

_________________________________________________________

c.
Would any of the sons be color blind?

_________________________________________________________

16.
A pigment-eyed, dimple-chinned man and a blue-eyed woman without a
dimpled chin have a child. The child is
blue-eyed and has a dimpled chin.

Gametes of First Parent

Gametes of the Second Parent

a.
What is the genotype of the father?

___________________________________________________________

b.
What is the genotype of the mother?

___________________________________________________________

c.
What alleles were carried by the father’s sperm?

___________________________________________________________

17.
Suppose a blue-eyed, dimpled chinned man whose father lacked a dimple
and a woman who is homozygous recessive for both traits have children:

Gametes of First Parent

Gametes of the Second Parent

a.
What would be the expected genotypic ratio of children produced in this
marriage?

b.
What would be the expected phenotypic ratio?

___________________________________________________________