Genetics Practice Quiz 20-21

Complete a Punnett square.

(You will need to this down on a piece of paper)

The following 3 questions will be about this Punnett Square.

Both parents are heterozygous for hair color.

Use the following information:

“B” is for brown hair and “b” is for blonde hair

• I completed the Punnett Square

• I need help

Based the punnett square from the 1st question, what is true about the parents?

• They have the same genotype and phenotype.

• They have different phenotypes and genotypes.

• They have the same genotype but different phenotypes.

• They have the same phenotype but different genotypes.

Based on the Punnett Square from the 1st question, What is the probability of having an offspring with brown hair?

• 25%

• 50%

• 75%

• 100%

Based on the punnett square from the 1st question, what is the probability of having an offspring that is heterozygous for hair color?

• 25%

• 50%

• 75%

• 100%

What is the description of the genotype TT?

• Homozygous Recessive

• Homozygous Dominant

• Heterozygous Recessive

• Heterozygous Dominant

In humans, B is the allele for brown eyes and b is the allele for blue eyes. Two brothers both have brown eyes, but one of them has both the B and b alleles while the other only has the B alleles. Which statement is true about the brothers?

• They have the same genotype and phenotype.

• They have different phenotypes and genotypes.

• They have the same genotype but different phenotypes.

• They have the same phenotype but different genotypes.

The pedigree above is tracking Huntington’s Disease. There are NO CARRIERS for this disease.

Which of the following is a family member with Huntington’s disease?

• II-4

• II-7

• II-8

• II-1

Is Huntington’s disease caused by a dominant or recessive trait?

• Dominant

• Recessive

How many children did individuals I-1 and I-2 have?

• 2

• 5

• 6

• 8

How many girls did II-1 and II-2 have?

• 1

• 2

• 3