Signaling in Single-Celled Organisms

Free Response

What characteristics make yeasts a good model for learning about signaling in humans?

Hint:

Yeasts are eukaryotes and have many of the same systems that humans do; however, they are single-celled, so they are easy to grow, grow rapidly, have a short generation time, and are much simpler than humans.

Why is signaling in multicellular organisms more complicated than signaling in single-celled organisms?

Hint:

Multicellular organisms must coordinate many different events in different cell types that may be very distant from each other. Single-celled organisms are only concerned with their immediate environment and the presence of other cells in the area.

Pseudomonas infections are very common in hospital settings. Why would it be important for doctors to determine the bacterial load before treating an infected patient?

Hint:

Doctors would need to determine if the patient is simply infected with free bacteria, or has developed a biofilm. Biofilms of Pseudomonas aeruginosa have a different pattern of gene expression than free bacteria, leading to increased virulence and resistance to many antibiotics.