Resistance Gene: A gene that provides an organism with the ability to withstand a harmful substance or condition, such as a pesticide.
Cross-Resistance: The development of resistance to one pesticide can sometimes lead to resistance against other related pesticides. It's like if your paintball-proof suit also made you immune to water guns and nerf darts.
Co-evolution: The process where two or more species influence each other's evolution. For example, as we develop new pesticides, pests evolve new resistances, which in turn drives us to develop even newer pesticides.