Cell membrane or in planet cells: cell wall AND membrane
The plant diversity decrease making that plant existence extinct
Invasive species. Native grasses have evolved with the normally-occurring grazing organisms to achieve a level of reproduction which sustains the grasses despite the grazing. An invasive species disrupts this ecological balance that took millions of years to develop by eating the grass at a rate that exceeds the rate for the grass to re-seed itself and maintain its own population. The invasive species easily decimates the grass population.
Parents have many responsibilities to their children, these responsibility must be taken seriously in order to keep the children in the right path. The parental responsibility that I will personally found very interesting is teaching my children how to do different stuffs. Like teaching them cook different dishes and cookies or teaching them to play different games or teaching them funny tricks in mathematics.