concentration can also mean water-molecule concentration you can write either way but it is given water then consider it to be water-molecule concentration.
According to Mendel's law of independent assortment ,when there are two pairs of contrasting characters ,the distribution of one pair into the gametes is independent of the other pair.
The leaves would wilt because the water wont reach up to the upper part to the leaves and they would ultimately lose their turgidity after transpiring the remaining water.