Tay-Sachs is a recessive lethal disease in which there is neurological deterioration early in life. This disease is rare in the population overall but is found at relatively high frequency in Ashkenazi Jews from Eastern Europe. A woman has a maternal uncle who had the disease. Her father does not come from a high-risk population. Her husband’s sister died of the disease at an early age. Draw the pedigree of the individuals described. Include the genotypes where possible.

Albinism, lack of pigmentation in humans, results from an autosomal recessive gene designated a. Two parents with normal pigmentation have an albino child. What is the probability that their next child will be albino? What is the probability that the next child will be an albino girl? If the child is normal, what is the probability that it will be a carrier (heterozygous) for the albino gene?

The following pedigree illustrates the inheritance of a rare neurologicaldisease. What is the most likely mode of inheritance for this disorder?Explain your reasoning.

Albinism in humans is autosomal and fully recessive to normal color. A couple, who are both normal, have a daughter who is albino and a son who is normal. What is the probability that their normal son is a carrier of the albinism gene?

Duchenne’s muscular dystrophy (DMD) is an X-linked disease that causes progressive muscle weakness and is often fatal. “XD” represents the wild type allele, and “Xd,” the mutant allele. Jonah is XDXd Y and his brother Pete is Xd Y. Jonah and Pete BOTH have DMD of equal severity and phenotypes. You might have thought Jonah’s DMD would be less severe given his genotype. To better understand the situation, you investigate Jonah’s Xist chromosome region in his defective muscle cells. Which of the following is consistent with his phenotype? (Select all that apply.) The Xd-containing chromosome is inactive in defective muscle cells. The XD-containing chromosome has a methylated Xist promoter. The XD-containing chromosome has an unmethylated Xist promoter. The Xd-containing chromosome is active in defective muscle cells.

People with polydactyly have more than five fingers or toes on their hands or feet. Polydactyly results from an autosomal dominant genetic disorder. Draw a pedigree for a family with polydactyly, using the following information:  Zack has polydactyly but his wife, Zoe does not.  Zack and Zoe’s daughter Yolanda has polydactyly but their son Yogi does not.  Yolanda has two children with her husband, Xavier, who does not have polydactyly:  Wilma, who is normal and Wade, who has polydactyly.  Use your pedigree to determine what is Zoe's genotype. A) DD B)dd C)Dd

In this case a family history revealed a genetic basis for the disorder. The pedigree is shown in Fig. 1 Below. Key Ø Female: affected Female: unaffected || IV V 5600 orize 077808 15 10 9 10 CHO વ Male: affected Male: unaffected Deceased Disease status not given Dizygotic twins Monozygotic twins Fig. 1 Disease pedigree. Five generations I, II, III, IV, V are shown. Females are represented by circles, males by squares, dizygotic (non-identical) twins by diagonal lines originating from the same point, Monozygotic (identical) twins by diagonal lines originating from the same point and joined symbols and deceased by a diagonal line through the symbol. Filled symbols indicate that the individual displays the disease phenotype. Unfilled symbols indicate that the individual does not display the disease phenotype. Carriers of the disease are not indicated. Information on disease status is not known for generation I and is omitted for the individuals represented by a symbol with an asterisk.…

Adenike and her partner, Debare, are expecting their first child. Adenike is healthy as are her two sisters but her brother has PKU, a recessive disorder of the PAH gene. Genotypically he must be pah-/pah-. Neither of Adenike's parents has PKU but both of her grandmothers did. Debare is a carrier of Sickle Cell trait, which means he has one allele for wildtype hemoglobin (HbA) and one allele for Sickle Cell (HbS), making him HgA/HbS. More importantly, he has two alleles for Marfan Syndrome, a pleiotropic dominant disorder that can affect up to 30 different traits (M+/M+). No one in Debare's family has ever had PKU and no one in Adenike’s family has ever had Sickle Cell or Marfan Syndrome. They consult a genetics counselor over concern of the health of their baby. The genetics counselor collects the medical histories of three generations; their grandparents, their parents, and them. In her calculations, she produces a phenotypic key that indicates M = Marfan, Hb = sickle cell, and pah-…