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Genetics and Genomics

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Inheritance of Organelle Traits

GENES-Z@X3JF

Baker's yeast is a single celled eukaryotic organism that can exist as either a haploid or a diploid. Haploids of opposite mating types can be induced to mate. The resulting diploid can then be induced to undergo meiosis resulting in four haploid spores.

Baker's yeast has a mutant form that is called "petite" because the yeast with this mutation form much smaller colonies. This small size is because the cells are growing much more slowly because they cannot extract as much energy from the nutrients they are given. They are unable to efficiently utilize the nutrients as the petite yeast have lost the ability to use oxidative phosphorylation to generate more ATP.

If you were to mate a petite yeast with a normal yeast of the opposite mating type and then induce the diploid to sporulate, which of the following segregation patterns would you most likely see?

A

4 petite spores and 0 large spores.

B

3 petite spores and 1 large spore.

C

2 petite spores and 2 large spores.

D

1 petite spore and 3 large spores.

E

0 petite spores and 4 large spores.