PRACTICE: Pedigrees, Karyotypes, Basic Genetics

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

• 2
• 3
• 5
• 6

Examine the pedigree. The allele for the presence of a widow’s peak is dominant. Therefore, we can tell from the chart that in the couple labeled 2:

• the male is heterozygous and the female is homozygous.
• the male is homozygous and the female is heterozygous.
• the male is homozygous and the female is homozygous.
• the male is heterozygous and the female is heterozygous.

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

• Cousins
• Dad and Daughter
• Uncle and Niece
• Grandpa and Granddaughter

Why do all the daughters in Generation II carry the colorblind gene?

• Because mom passed on the gene.
• Because dad passed on the X chromosome.
• Because their brother has it.
• Because their brother gave it to them.

Why does individual IV-7 have colorblindness?

• Because his mom is a carrier.
• Because his dad has it.
• Because his siblings have it.
• Because his uncle has it.

Give the genotype for person III-3

• GG
• Gg
• gg

Give the genotype for person II-1

• GG
• Gg
• gg

Which individual in the first generation is a carrier?

• The male
• The female
• individual 1
• None of the above

If this pedigree shows a recessive disorder, what MUST the genotype of individual II-3 be?

• HH
• Hh
• hh
• None of the above

What is the mode of inheritance shown here?

•  Recessive
• Sex Linked
•  Dominant