TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Tight junction is the term for a watertight seal between two adjacent animal cells.

SOLUTION: What is the term for a watertight seal between two adjacent animal cells?

PROBLEM: Exotic species are also called invasive species because they threaten other species.

SOLUTION: Why are exotic species also called invasive species?

PROBLEM: One domain is common in two eukaryotic proteins.

SOLUTION:
What is common in two eukaryotic proteins?