Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

The discovery of ribozymes nullified the idea that all biological catalysts are proteins.
What nullified the idea that all biological catalysts are proteins?

When the smooth muscle relaxes, the arterioles dilate, allowing blood to enter the capillaries.
When the smooth muscle relaxes, the arterioles dilate, allowing blood to enter the what?

Fungi may form mutualistic relationships with plants, algae, cyanobacteria, and animals.
Fungi may form mutualistic relationships with plants, algae, cyanobacteria, and what?