Genetics Review

Aa, DD, bB, yy are all examples of

• genotypes
• phenotypes

AA and Aa always show up as

• dominant
• recessive

What ratio of the offspring from the cross shown will be homozygous recessive for the  trait of tallness? 

• 0 in 4
• 1 in 4
• 2 in 4
• 4 in 4

Which of the following genotypes is homozygous dominant?

• A
• Aa
• AA
• aa

Which of the following genotypes is heterozygous?

• Bb
• BB
• bb
• B

In a heterozygous genotype, the ___________ allele takes over in the phenotype.

• recessive
• dominant
• lower case letter
• both 

What you see, or the physical appearance.

• Genotype
• Phenotype
• Homozygous
• Heterozygous

B = brown eyes
b = blue eyes
What is true about these two brothers that have brown eyes?
One has genotype BB the other Bb.

• they have same phenotype and genotype
• they have different genotypes and phenotypes
• they have same phenotype but different genotypes
• they have same genotype but different phenotypes

Having a Widow's Peak is dominant (W) over not (w). If parent A (WW) and parent B (ww) have a child, what is the likelihood that--

• 100%

• The genotype of these children

• 0%

• The child will not have a widow's peak

• Ww

• The child will have a widow's peak

Brown eyes (B) tend to be dominant whereas blue eyes (b) tend to be recessive. Parents with heterozygous genes want to know: what is the likelihood of them having a child with blue eyes?

• 0%

• 25%

• 75%

• 100%