Solved by a verified expert:BIO 111: Inheritance
Problem Set
Allele Combinations
One gene has alleles A and a. Another has alleles B and
b. For each of the following genotypes, what type(s) of gametes will form,
assuming independent assortment during meiosis occurs?
AABB
AaBB
Aabb
AaBb
Refer to problem 1. Assume you now study a third gene
having alleles C and c. For each genotype listed, what type(s) of gametes
will be produced, assuming independent assortment during meiosis occurs?
AABBCC
AaBBcc
AaBBCc
AaBbCc
Monohybrid cross
Among the dragons of middle earth the following traits show
classic dominant-recessive inheritance patterns:
G = golden skin color is dominant to g = green skin color
E = can sense emotions is dominant to e = cannot sense emotions
F = fire breathing is dominant to f = bad breath but no fire
Use these traits and symbols to work the following problems.
What is the genotype of a pure breeding golden skinned
dragon?
What is the genotype of a green skinned dragon?
If the pure breeding green skinned dragon mates with
the pure breeding golden skinned dragon, what will the expected phenotype
and genotype of their progeny?
If two dragons heterozygous for skin color mate, what
will be the genotype and phenotype ratios of their offspring? If 16 baby
dragons are born, how many are green? How many are golden?
A dragon heterozygous for emotion sense mates with one
that cannot sense emotions. They have 20 babies. How many would be
expected to be able to sense emotions?
Gandalf has a fire-breathing dragon and wants to know
if it is a pure breeding dragon for this trait. How will he determine
this?
Dihybrid Cross -Use the same dragon
traits as in the above problems.
A male dragon heterozygous for skin color and fire
breath mates with a female that is also heterozygous for these traits.
What will be the phenotype ratio of their offspring? They produce 10
offspring. How many would be expected to breathe fire and have green skin?
A green, emotion sensing male (heterozygous for emotion
sense) mates with a female that is heterozygous for both traits. How many
of their 12 babies should have each phenotype?
A golden-skinned female who has emotion sense and can
breathe fire is mated to a green-skinned male who cannot sense emotion and
has no fiery breath. All of their offspring have golden-skin and emotion
sense but half are fire breathers and half are not. What are the most
probable genotypes of the momma dragon, the daddy dragon, and the baby
dragons?
Lethal Alleles
Certain alleles are so essential form normal
development that an individual who is homozygous recessive for a mutant
form cannot survive. Such recessive, lethal alleles can be perpetuated in
the population by heterozygotes.
Consider the allele Manx (ML) in
cats. Homozygous cats (MLML) die when they are still
embryos inside the mother cat. In heterozygotes (MLM), the
spine develops abnormally. The cats end up with no tail.
Two MLM cats mate. What is
the probability that any one of the surviving kittens will be heterozygous?
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