According to the world resource institute, biodiversity is the variety of the world's organisms, including their genetic diversity. in a world of genetically modified (gm) crops, agriculture is greatly reducing the genetic diversity of the plants on earth. if we ignore genetic diversity while we develop gm products, we risk a disease or pest emerging that will wipe those types out. one answer to this problem is seed banks. storage of material in the form of seeds is one of the most widespread and valuable ex-situ approaches to conservation. all but one is an advantage of seed banking over other ex-situ methods of biodiversity conservation. that is a) seed banks take up little space. b) seeds are viable for a very long time. c) seed banks are expensive to maintain. d) samples are very small and easily handled.