It’s called a solar system because solar means “relating to or determined by the sun” and system means “a set of things working together as parts of a mechanism or an interconnecting network” and the solar system is a whole bunch of planets and other things that are related to the sun and working together.
Plant cells have a cell wall so answer 1
It only allows certain things through, such as water. One way to remember it is to think about how you wouldn’t eat just anything, and the cell doesn’t let just anything in. I hope this helps