A student cultivates seedlings in four separate test-tubes. Tube W has every mineral ion required for healthy plant growth. The diagram illustrates what these seedlings look like after two weeks. What are present in tubes X, Y and Z?
- AX: all minerals except magnesium ions; Y: all minerals except nitrate ions; Z: water
- BX: all minerals except magnesium ions; Y: water; Z: all minerals except nitrate ions
- CX: all minerals except nitrate ions; Y: all minerals except magnesium ions; Z: water
- DX: water; Y: all minerals except magnesium ions; Z: all minerals except nitrate ions