Unit 9 Study Guide Review

Letters that represent different forms of the gene.

Dominant Allele: A
Recessive Allele: a

​Alleles

​The combination of alleles (letters).

Homozygous Dominant: AA Homozygous Recessive: aa
Heterozygous: Aa

Genotype

This is the physical appearance of a trait.

What does it look like?

AA - Dominant trait expressed
Aa - Dominant trait expressed
aa - Recessive trait expressed

Phenotype

Multiple Choice

What genotype belongs in the empty square?

• bb

• BB

• Bb

• Not enough information

Fill in the Blanks

Multiple Choice

Predict the potential genotypes and phenotypes (curly & straight hair) resulting from a cross between 2 parents.  One is homozygous dominant with straight hair & the other is heterozygous.  What percentage of offspring will have straight hair?

• 50%

• 25%

• 100%

• 75%

Multiple Choice

Predict the potential genotypes and phenotypes (curly & straight hair) resulting from a cross between 2 parents.  One is homozygous dominant with straight hair & the other is heterozygous.  What percent will have a homozygous recessive genotype?

• 25%

• 50%

• 0%

• 75%

Multiple Choice

Mr. Krabbs is heterozygous for his tall eyeballs, while his wife has short eyeballs.  What is the probability that their children having a heterozygous genotype?

• 0%

• 50%

• 25%

• 100%

Multiple Choice

Mr. Krabbs is heterozygous for his tall eyeballs, while his wife has short eyeballs. What is the probability of having a homozygous dominate genotype?

• 0%

• 25%

• 50%

• 7

Fill in the Blanks

Multiple Choice

Which genotype(s) belong in box Y?

• Ee

• ee

• EE

• EE or Ee

Fill in the Blanks

Multiple Choice

How many generations are shown in this pedigree?

• 1
• 2
• 3
• 4

Multiple Choice

What do half colored symbols represent?

• The individual is a carrier (heterozygous).
• The individual expresses the trait.
• The individual has both recessive alleles.
• The individual has both dominant alleles.

Multiple Choice

What does an open circle represent?

• Not Affected Male
• Not Affected Female
• Affected Male
• Affected Female

Multiple Choice

In the second generation-how many people are carriers of the trait?

• 2
• 3
• 5
• 6

Multiple Choice

How many people in this whole pedigree have the trait/disease?

• 2
• 3
• 4
• 6

Multiple Choice

If a trait SKIPS a generation, it is an indication that the trait is....

• dominant
• recessive
• incompletely dominant
• co-dominant

Multiple Choice

What does a horizontal line between a square and a circle mean?

• They are siblings
• They are cousins
• They are married ("together")
• They are the children

Multiple Choice

Objective #13

This is a pedigree that follows blue eyes which is a recessive trait. What is the phenotype of the mother (circle) in generation 1?

• Brown

• Blue

• 1 blue, 1 brown

Multiple Choice

Is this trait (the shaded individuals) dominant or recessive?

• dominant
• recessive

Multiple Choice

How are individuals III-2 and II-4 related?

• Brother and sister

• Dad and daughter

• Uncle and niece

• Grandfather and granddaughter

Multiple Choice

What is the mode of inheritance shown here?

• Recessive because it "skips" a generation

• Dominant because it shows up in every generation