This paper describes a simple, rapid and low-cost technique for growing bacteria (or other microbes) in an environmental gradient, in order to determine the tolerance of the microbial population to varying concentrations of sodium chloride ions, and suggests how the evolutionary response of a microbial population to the selection pressure of the…

The following experiment describes an easy experiment for children 11-12 years old, performed during spring in a compulsory school near Karlstad, Sweden. Four different ripe fruits were placed under flowering plants of Impatiens New Guinea (Impatiens hawkeri) for four days on a table and with plastic bags around both plants and fruits. For one of…