Draw Urey and Miller’s experimental setup and label it.

Answer:

[Figure: Urey and Miller’s apparatus — a flask of boiling water (heat source below) connected by a tube to a large 5-litre gas chamber containing CH₄, NH₃, H₂ and water vapour with two tungsten electrodes producing electric sparks; from the chamber a tube passes through a condenser (cold water in and out) into a U-shaped trap where the condensed liquid with organic compounds collects; a stopcock/sample point on the trap; the loop returns to the boiling flask. Vacuum pump connection marked.]

Labels: boiling water (source of water vapour), heat, gases CH₄, NH₃, H₂, H₂O, electrodes (electric discharge), condenser with cold water in/out, trap (U-tube) with water containing organic compounds, sampling point.

After about a week the water in the trap contained simple amino acids (e.g. glycine, alanine), sugars and other organic compounds, supporting chemical evolution (Oparin–Haldane theory).