Question

1. thylakoid sacs in chloroplasts are called

Explanation:

In chloroplasts, the thylakoid sacs (individual flattened sacs) are called thylakoids (or sometimes "grana thylakoids" if part of a granum, but the basic term for the sacs is thylakoid; however, if referring to the stacked structures, grana are stacks of thylakoids, but the sacs themselves are thylakoids. Wait, correction: The thylakoid sacs (the individual membrane - bound sacs) are called thylakoids, and when they are stacked, the stacks are called grana. But the question is about the thylakoid sacs (the individual sacs) in chloroplasts, so the answer is thylakoids (or sometimes the term "thylakoid" refers to the sac itself). Wait, actually, the thylakoid is the sac - like structure. So the thylakoid sacs in chloroplasts are called thylakoids. Alternatively, if considering the stacked arrangement, but the question is about the sacs (the individual units), so the answer is thylakoids.

Answer:

thylakoids