You and your lab partner have isolated 20 new mutant yeast strains that are defective in synthesis of threonine, an amino acid. These Thr- mutants do not grow on minimal medium, but they do grow on minimal medium supplemented with threonine. Ten of your Thr- mutants (numbered 1 through 10) were isolated in a strain of mating type a (MAT a). The other 10 Thrmutants (numbered 11 through 20) were isolated in a strain of mating type α (MAT α). You and your lab partner cross each of the MAT a strains to each of the MAT α strains, and you include crosses to the appropriate wild-type strains. Your experimental observations are shown in the table below, where (-) indicates diploids that did not grow on minimal medium and (+) indicates diploids that did grow on minimal medium.

Which mutations are dominant?

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#Question id: 2390

#Unit 2. Cellular Organization

In addition to self assembly, enzymes may facilitate wall assembly. A prime candidate for enzyme-mediated wall assembly is-

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#Question id: 12488

#Unit 8. Inheritance Biology

Retinoblastoma usually occurs as a sporadic event but in around 10% of cases there is a positive family history due to autosomal dominant inheritance. In these families the penetrance is approximately 80% (= 0.8). A woman with retinoblastoma, whose father and grandfather were also affected, has an unaffected partner with no relevant family history. Which of the following is correct regarding their children?

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#Question id: 1477

#Unit 4. Cell Communication and Cell Signaling

The effector proteases in the apoptotic pathway, the caspases, are so named because

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#Question id: 5011

#Unit 11. Evolution and Behavior

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of

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#Question id: 2052

#Unit 4. Cell Communication and Cell Signaling

Why have pigs have been proposed as a source of organs for xenotransplantation to humans?