In any study or research, the variable is that measured or affected by the change occurs lace in an experiment is called the dependent variable. The dependent variable depends on the factors or the variables that are changed in the experiment.
In this particular study, the variable which is measure is the height or growth of the plant which depends on the change in the hydrating supply so the dependent variable will be - the growth of the plant.
Both parents are heterozygous carriers. Sickle Cell Anaemia is usually referred to as a recessive condition since an individual must have two copies of the sickle gene in order to have the disorder.
Since neither of the parents is ill, both of them must be heterozygous carriers for the child to have the disorder
