The shape of a heliodor is an X-linked trait. Male heliodors inherit two X chromosomes, while the females inherit an X and a Y chromosome. The recessive allele codes for the common bell-shape 2 while the dominant phenotype is a round shape O.Hudson is a round male and has offspring with Heidi, a bell-shaped female. They already have one daughter, Hannah, who is shaped like her mother. What is Heidi's genotype? XRY XRXR

A certain type of deafness in humans is inherited as an X-linked recessive trait. A man with this type of deafness married a normal woman, and they are expecting a child. They find out that they are distantly related. Part of the family tree is shown here.How would you advise the parents about the probability of their child being a deaf boy, a deaf girl, a normal boy, or a normal girl? Be sure to state any assumptions that you make.

Shown below is a pedigree for a completely penetrant trait called Adams syndrome in which babies are born blind. This trait occurs when an allele of the adams gene is associated with ≥200 tandem trinucleotide repeats (the normal number is 10). First cousins, III-1 and III-2 married and their first child (IV-1) was blind. For their next child, they decided to do in vitro fertilization with III-1's sperm and III-2's eggs to generate six embryos (labeled E1-6). When each embryo contained eight cells, a single cell was removed and genomic DNA was isolated. PCR reactions using primers that flank the trinucleotide repeat region were then performed and the resulting fragments were fractionated on an agarose gel. PCR reactions using genomic DNA from III-1, III-2 and IV-1 were included as controls. The DNA was visualized using a fluorescent dye and the gel is shown below. Based on this information, select the best answer from the list to the questions below. || E1 = embryo 1 IV E1 E2 E3 E4 E5…

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-…