You have discovered a single celled organism that you have determined is in either Domain Archaea or Kingdom Fungi. What piece of evidence would you look for to determine to which of these groups it belongs

The Cell structure.

Explanation: Most Archaeas don't have membrane-bound organelles, they are mostly unicellular prokaryotic organisms.

Archaea are found living alongside bacteria in many environments. Recently Archaea belongs to Crenarchaeota have been implicated in nitrogen cycling in the soil.

Fungi are eukaryotic multicellular organisms and they have membrane-bound organelles. they are hence more closely related to plants and animals than to bacteria or archaea. Like eukaryotes, Fungi has nuclei with chromosomes that contain DNA. They possess membrane-bound organelles such as mitochondria. Fungi are heterotrophs, and they are saprophytic, they feed on decaying matter. some fungi occur as unicellular organisms, they are generally referred to as yeasts.

in a word, a scientific question is testable. a testable question is one that asks about objects, organisms or events found in the world around it