Question

Researchers studying yeast discovered that, for some mutants, when the temperature at which the cells are grown is elevated from 25ºC to 37ºC, their secretory pathway no longer functions and the cells grow dense with unsecreted protein.

When these cells are examined microscopically, they can be divided into groups that vary in terms of where the unsecreted proteins accumulate. In some of the mutants, proteins accumulate in the ER; in others, the Golgi; in others, they accumulate in vesicles near the plasma membrane.
What is the likely explanation for this difference in appearance?
Choose one:_________
A) The temperature-sensitive mutant proteins accumulate in different compartments
B) Different temperature-sensitive mutations promote an increase in protein synthesis.
C) Different temperature-sensitive mutations disrupt protein synthesis.
D) Different temperature-sensitive mutations disrupt the integrity of cell membranes.
E) Different temperature-sensitive mutations affect different stages of the transport process.

Answer 1

The correct option is E. Different temperature-sensitive mutations affect different stages of the transport process.

Step-by-step explanation:

After a protein is made in the ribosome by the process of translation, it travels to the endoplasmic reticulum. From the endoplasmic reticulum, it moves to the Golgi complex for packaging. After being packed, they are transported out of the cell to the areas where they have to function. Hence, the accumulation of proteins in this area shows that the temperature-sensitive mutations have affected the transport cycle of the proteins.