Q9 - Identifying the Ohsumi Yeast Autophagy Mutant and Autophagic Body Contents

All cells must constantly synthesize and degrade intracellular substances and structures, one of processes is autophagy. In autophagy, the intracellular structure is non-specifically or somehow specifically decomposed by lysosomes and vacuoles. The first molecular analysis of autophagy was carried out by Nobel Prize winner, Dr. Ohsumi, by using yeast mutant, as follows.

1. His group cultured a yeast mutant under nitrogen starvation.
2. After a certain period, many round structures (autophagic bodies, AB) appeared in the vacuoles (V).
3. When observed with an electron microscope, ribosomes were found in the autophagic body.
4. Mutants of this process were isolated and many genes that work in the autophagy system were found out.

Figure 1.

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

Question reproduced from IBO 2020, Theoretical Exam 2, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)