Q17 - Mating-Type Switching in Budding Yeast

Theoretical B Real exam question - full text reproduced under IBO's CC BY-NC-SA 4.0 license

Gene Regulation: Eukaryotic & Epigenetics

Yeast (Saccharomyces cerevisiae) has a mating pattern with both haploid and diploid cells, mitosis and meiosis, and two kinds of mating types. Haploid cells may even switch mating type (Fig.).

A, mating-type switching in budding yeast (M, mother cell; D, daughter cell. a and α, mating types). Fig. A I. mitosis in haploids; A II: mating and diploid formation; B, budding in haploid yeast. Both in Fig. A and B, green filling indicates the repressor factor protein Ash1p.

Figure 1. Figure 1.

Using the information and data, determine which of the statements are true or which are false.

A. Mating in yeast can only take place between two different kinds of haploid cells

B. Mating-type switching occurs only in the mother cell of each haploid generation

C. Mating type shift is induced by the repressor factor Ash1p

D. Mating type shift of haploids and the meiosis of diploids result in maximum mixing of mating types

← Previous: Q16 Next: Q18 →

Question reproduced from IBO 2015, Theoretical Exam B, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)