Question

Using the yeast mating factor as an example, support the hypothesis that signaling pathways appeared early in evolution and are well-conserved. Evaluate the explanations provided to select the one that best supports the hypothesis.

a) Divergence of signaling components
b) Evolutionary conservation of pathway components
c) Absence of signaling in yeast
d) Incompatibility with eukaryotic signaling

Answer 1

The yeast mating factor supports the hypothesis that signaling pathways appeared early in evolution and are well-conserved due to evolutionary conservation of pathway components and similarities in signaling mechanisms between yeast and higher organisms.

Step-by-step explanation:

The hypothesis that signaling pathways appeared early in evolution and are well-conserved can be supported using the example of the yeast mating factor. In yeast, signaling uses an endocrine pathway and is evolutionarily conserved, similar to insulin signaling in humans. This indicates that signaling pathways have been conserved throughout evolution and are crucial for cellular communication in diverse organisms.

Additionally, yeasts contain many of the same classes of signaling proteins as humans, making them ideal for studying signaling cascades. Yeasts are simpler organisms than humans or other multicellular animals, making their signaling cascades simpler and easier to study, although they share similarities with human signaling.

Therefore, the evolutionary conservation of pathway components and the similarities in signaling mechanisms between yeast and higher organisms provide strong support for the hypothesis that signaling pathways appeared early and are well-conserved.