Plants and animals live in interacting, interwined communities. There is a characteristic set of species in different environments. For example, certain species of trees, shrubs, ground cover, arthropods, reptiles, mammals, birds etc. live in a temperate forest environment. A completely different set of creatures live in a marsh, or a grassland or an agroecosystem. However, the relationships between these groups can be defined by the ecological role they play, the flow of energy between them and the cycling of nutrients between them. This is a fancy way of saying "everything is connected"! And if you change one part of the system, something else changes. In an ecosystem management decision, you hope you know what those consequences of your actions are!) This is important in managing agroecosystems as well.
The new cells would have incorrect number of chromesomes
You would be crossing Pp and Pp. If you put them in a punnet square, the four possible gene combination you get would be PP, Pp, Pp, and pp. In all cases except the last, the resulting flower's phenotype would be purple. So the probably of purple flowered offspring is 75%, or 3/4.
1) Enzyme activity
2) Cell to cell recognition
3) Cell signalling
4) Transport Materials.
Hope this helps! :)