Subcellular components can be separated by the help of . . . . . . .

Which of the following statements is/are correct?
$(i)$ The shape of the cells may vary with the function they perform.
$(ii)$ Human $RBC$ is about $7.0 \; \mu m$ in diameter.
$(iii)$ Cytoplasm is the main area of cellular activities.
$(iv)$ Various chemical reactions occur in cytoplasm to keep the cell in the living state.

In a compound microscope,the magnification is $NOT$ consistent with which of the following?

Find the correct set of structures/organelles not surrounded by membrane.

Which components are responsible for the organization of a cell?

What is common in mitochondria,chloroplast and nucleus?