The cell membrane and police both allow specific things to come in and out. The cell membrane allows certain molecules in and out of the cell and the police allow certain people in and out of a community.

The nucleus controls the cell and the mayor controls the city

Mitochondria generates energy for the cell and a power plant generates energy for a city

Ribosomes produce proteins for cells and a farm produces foods like protein for the people of the city

The ER makes proteins, lipids, and carbohydrates for cells and the restaurants make different foods for the people

A post office is like the Golgi apparatus because it sorts and packages mail like how the Golgi apparatus sorts and packages proteins

The central vacuole stores water, salts, proteins, and carbohydrates like how the grocery store stores food and drinks.

Cytoskeleton helps cells maintain their shape like how scaffolding helps buildings maintain their shape

The city border surrounds and protects the city from any hard just like how the cell wall shapes and protects the cell

Solar panels use sunlight to produce energy like chloroplast

Cargo-trains store and transport goods like how vesicles store and transport materials

The government assembles laws and the Nucleolus assembles ribosomes

The cytoplasm is outside the nucleus like how the residential area is outside of the government

The chromatin spreads out and creates chromosomes like how the workers of city hall spread out and create government ideas