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Pedigree Practice



Multiple Choice
Identify the choice that best completes the statement or answers the question.

SPI 3210.4.4  Determine the probability of a particular trait in an offspring based on the genotype of the parents and the particular mode of inheritance.
 

 1. 

Baldness is the loss of human hair on the head and is a recessive sex-linked trait.  a male with the recessive genotype and a female heterozygous for the genotype have children.  What is the probability that a female child will inherit the baldness trait?
a.
0%
c.
100%
b.
25%
d.
50%
 

 2. 

The gene for flower color in some plants displays incomplete dominance.  In one plant species, the genotypes (RR) yield red petals, (rr) yield white petals, and (Rr) yield pink flowers.  What is the probability a cross between two plants heterozygous for flower color produce pink-flowering offspring?
a.
75%
c.
50%
b.
100%
d.
0%
 

 3. 

The pedigree below shows the inheritance of a trait in humans.
mc003-1.jpg

Which pattern of inheritance is shown in this pedigree?
a.
polygenic
c.
recessive sex-linked
b.
simple dominance
d.
codominance
 

 4. 

The pedigree chart below shows the transmission of a genetic trait over several generation.
mc004-1.jpg

What type of inheritance pattern does the pedigree display?
a.
autosomal dominant
c.
sex-linked recessive
b.
sex-linked dominant
d.
autosomal recessive
 

 5. 

The illustration below shows a pedigree with an autosomal recessive mutation. mc005-1.jpg
What is the possibility that the male in the F2 generation will express the mutation?
a.
100%
c.
50%
b.
25%
d.
75%
 

 6. 

The pedigree chart below show the transmission of a genetic trait over several generations.
mc006-1.jpg
which statement provides the most support that the trait is a sex-linked trait on the Y chromosome?
a.
the trait is present in all generations.
c.
The trait show up in all sons of affected males.
b.
The trait is passed to females.
d.
The trait show up only in males.
 

 7. 

The inheritance of a genetic trait is shown in the pedigree below.
mc007-1.jpg
Based on the pedigree, how is the trait inherited?
a.
sex-linked dominant
c.
autosomal dominant
b.
sex-linked recessive
d.
autosomal recessive
 

 8. 

The inheritance of a mutation is shown in the pedigree below.
mc008-1.jpg
What is the genotype of the male in the F2 generation?
a.
XAY
c.
XAXA
b.
XaY
d.
XaXa
 

 9. 

In snapdragons, if white flowers are crossed with red flowers, all the offspring have pink flowers.  When two pink snapdragons are crossed, some offspring have white flowers, some have red flowers, and some have pink flowers.  Which inheritance pattern do snapdragon flowers exhibit?
a.
sex-linked trait
c.
incomplete dominance
b.
polygenic trait
d.
codominance
 

 10. 

The transmission of a genetic disorder is shown in the pedigree below.
mc010-1.jpg
Which statement best describes why this trait is sex-linked?
a.
The trait is absent in the second generation males of the parent generation.
c.
The trait is expressed only in males and not expressed by females.
b.
The trait is absent in the first generation female.
d.
The trait is only inherited from a female carrier.
 

 11. 

The pedigree below shows data of an inherited human trait.
mc011-1.jpg
What type of inheritance is displayed in the pedigree?
a.
simple dominance
c.
codominant
b.
sex-linked
d.
autosomal recessive
 

 12. 

Hemophilia is a sex-linked genetic disease.  If a male with hemophilia and a homozygous normal female have a female child, what is the probability that the child will be a carrier for hemophilia?
a.
0%
c.
50%
b.
25%
d.
100%
 

 13. 

In humans, the allele for having a straight thumb is dominant to the allele for having a curved thumb.  A male is homozygous dominant for straight thumbs, and a female has curved thumbs.  What is the probability that their offspring has curved thumbs?
a.
0%
c.
50%
b.
25%
d.
100%
 



 
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