None of the above is the answerr
A granum (if you have 1 stack of thylakoids, this is singular). Also, if you have more than 1 stack of these they are collectively referred to grana.
The French marine explorer, inventor, filmmaker, and conservationist sailed the world for much of the late 20th century, educating millions about the Earth's oceans and its inhabitants—and inspiring their protection.
Answer:
3 and 4 are most closely related.
5 and 6 are also most closely related.
