Some scientists have collected and stored seeds for many types of food-producing plants. the purpose of
this is to
(1) increase the destruction of environments (3) decrease the dependence on plants for food
(2) continue the deforestation of world ecosystems (4) preserve the diversity of plant species

If scientists collect and store seeds samples this means that they want to have a collection of the species with the objective of being sure that the species won't disappear- with the objective of preserving the species.

If they collect seeds of many species, this means that they're interested in the diversity of species: the correct answer is (4) preserve the diversity of plant species

There is a desire in general on the part of societies to improve their standard of living. This inevitably results in greater consumption of water, food, mineral, and energy resources and of our manufacturing capability. Although wastes and products that follow such consumption result in a greater burden on the environment, it is also true that the higher the living standard, the greater the resources that can be, and generally are, devoted to protecting human health and the environment.

Hope this helps...