Chap 12 Bio 12.1 Unit 4 pg 89

(7)Most common genetic disorder among white americans

A. Cystic fibrosis

(4)What is the likely genotype of II-4 for the trait being studied in the pedigree?

Accept any genotype that includes at least one uppercase letter.

(9)Widow's peak and hitch hikers thumb

B. Simple dominant traits

(5)Recessive disorder that results from the absence of an enzyme required to break lipids down

C. Tay-Sachs Disease

(6)Lethal genetic disorder caused by a dominate allele

D. Huntington's disease

(8)Recessive disorder that results from the absence of an enzyme that converts one amino acid into another one

E. Phenylketonuria

(1)Is the trait being studied in the pedigree recessive or dominant? How do you know?

Recessive. Because it only appears periodically.

(3)What is the probability that II-1 and II-2 will produce an individual with trait being studied? Draw a Punnett square to show your work.

The probability is 1:4. The Punnett square should show the cross of two heterozygotes.

(2)Are II-1 and II-2 carriers of the trait? How do you know?

Yes, they are carriers because they produced III-1, who has that trait.