Aim: To investigate the effect of different concentrations of heavy metal chloride on the growth of cress seedlings. Heavy metals like zinc, mercury, lead and cadmium are found in many places or items of everyday use. For example, mercury is found in batteries, cadmium in paints and lead is emitted from many car exhausts. All are toxic to plants and high amounts would most certainly cause malfunctions and eventually death of growing plants. However despite the fact that many of the heavy metals like zinc and copper whose role evidence suggests are as regulators and catalysts in the plant...
our inability to control the temperature, humidity and light meant that they could have acted as limiting factors not only altering the results but making them unfair as not all days were the same temperature or provided the same amount of light. A Dewpoint propagator maybe used to assist this problem as it enables one to control the above. The experiment should also ideally be conducted in a controlled environment where the light source is equal. We also observed the fact that at low concentrations the shoot growth was relatively unaffected whereas the root growth always decreased.