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Tay-Sachs disease is tested by

Marfan syndrome is a rare inherited human disorder characterized by unusually long limbs and digits plus defects in the heart (especially the aorta) and the eyes, among other symptoms. Following is a pedigree for this disorder in a certain family.  Affected individuals are shown with filled (black) symbols.  Assume complete penetrance.  What type of inheritance pattern do you think is more likely?

Which of the following would NOT be observed in a pedigree if a genetic disorder was inherited in a recessive manner?

In a person with Edward syndrome (Trisomy 18), a genetic imbalance occurs because

A Rr pea plant is crossed to another Rr plant.  What is the expected ratio of phenotypes for offspring from this cross?

A true-breeding plant with round and yellow seeds (RRYY) was crossed with a true-breeding plant with wrinkled and green seeds (rryy). Round and yellow seeds are dominant traits.  The F1 plants were crossed with plants with wrinkled green seeds (rryy).  Based on Mendel’s law (independent assortment), which of the following displays the expected ratio of phenotypes for the offspring?

An inversion heteozygote has a pericentric inversion (see blue sisterchromatid pair).  What is the result if crossing over occurs between genes F and G on an inverted (blue) and a normal chromosome (purple) in this individual?  After completion of meiosis, one chromosome would be normal (purple), and one would contain the inversion shown (blue).  What about the remaining two chromosomes?

An allele in fruit fly produces a star-like eye trait in the heterozygous individual. However, the star-eye allele is lethal in homozygotes. What would be the ratio of phenotypes of surviving offspring if star-eyed flies were crossed to each other?

A patient with unusually long limbs and joint hypermobility presents to the physical therapist with complaints of joint pain and weakness. During the checkup, a heart murmur is present, and further testing discovers that this patient has abnormal elastic connective tissue. Which of the following best describes their condition?

Bone tissue provides greater support than cartilage because its matrix is solid. This increased solidity is due primarily to the presence of ________.