en humanos, el gen que determina el color oscuro del pelo es dominante (P) frente al pelirrojo (p), el gen que determina el color pardo de los ojos (O) es dominante sobre el de los ojos azules (o). Un hombre de ojos pardos y pelo oscuro y una mujer tambien de pelo oscuro, pero de ojos azules, tuvieron dos hijos, uno de ellos pelirrojo y con ojos pardos, y el otro de pelo oscuro con ojos azules. representa este cruse, indicando los genotipos y los fenotipos . deduce los genotipos de su descendencia​

Waste water from industries and domestic sources can be treated by chlorination or ultraviolet radiation. there are pros and cons to using either chlorine or uv radiation to kill harmful microorganisms. what is one reason chlorination would be preferred over ultraviolet radiation? a) chlorine only eliminates visible impurities and is ineffective against microorganisms. b) chlorine not only kills bacteria but provides a residual effect on returning microorganisms. c) uv radiation can be used only to treat drinking water and is ineffective in treating waste water. d) ultraviolet radiation is more effective