Aresearcher is carrying out an experiment where she labels a protein with a fluorescent tag (so she can visualize its location in a cell) and introduces this tagged protein into the lumen of a single thylakoid. she observes her treated cells periodically and notices that the labeled protein can move between grana and is always in the lumen, but is never observed in the stroma. what can she deduce?

The protein likely travels through a common lumen shared by thylakoid membranes and grana, and cannot easily diffuse through the thylakoid membrane.

Explanation:

There is a lot of scientific research in which a specific molecule can be labeled with some fluorescent marker (usually carbon 14). This type of marking allows the researcher to make observations about the movement of these molecules, as you can see in the question above. About the research shown in the question, the researcher realized that the protein labeled with the fluorescent marker moved between the grana and was always in the lumen, so she can conclude that the selocomovement protein moved through the lumen that is shared between the tilacoid membranes and the grana.

the answer is d p: cell, q: organ, r: organ system, s: tissue