Which organelle has a single membrane?

You are asked to examine a cell using a powerful light microscope. The image you see has a clearly defined nucleus and mitochondria. It also has a large central vacuole and chloroplasts. From what group of organisms did this cell most likely come?

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.

Identify $X$ and $Y$ from the figure.

Which of the following structures between two adjacent cells forms an effective transport pathway?

Identify the labels $A, B, C, D$ and $E$ in the given diagram. The following components are listed:
$(i)$ $SER$
$(ii)$ Ribosome
$(iii)$ Nucleus
$(iv)$ Nuclear pore
$(v)$ $RER$