Figure 31.4 Use the Following Information When Answering the Corresponding Question(s)

Figure 31.4
Use the following information when answering the corresponding question(s) .
There is much discussion in the media about protecting biodiversity,but does it really matter? Canadian and Swiss researchers wanted to know if the diversity of arbuscular mycorrhizal fungi (AMF) was important to the productivity of grasslands (M.G.A.van der Heijden,J.N.Klironomos,M.Ursic,P.Moutoglis,R.Streitwolf-Engel,T.Boler,A.Wiemken,and I.R.Sanders.1998.Mycorrhizal fungal diversity determines plant biodiversity,ecosystem variability and productivity.Nature 396:69-72) .Specifically,they wanted to know if it mattered which specific AMF species were present,or just that some type of AMF was present.They grew various plants in combination with one of four AMF species,no AMF,or all four AMF species together;and they measured plant growth under each set of conditions.All plant species were grown in each plot,so they always competed with each other with the only difference being which AMF species were present.Use the graphs in Figure 31.4 to answer the questions that follow.Note that the x-axis labels indicate the number and identity of AMF species (bar 0 = no fungi;bars A-D = individual AMF species;bar A+B+C+D = all AMF species together) .The y-axis indicates the amount (grams) of plant biomass for the species shown in italics above each graph.

-Based on the van der Heijden et al.(1998) graphs in Figure 31.4,which of the following is the best description of the data supporting the idea that a plant species did not form mycorrhizae with a fungus?

A) Its biomass is greatest when no AMF are present.
B) Its biomass is greatest when AM fungus A is present.
C) Its biomass is greatest when AM fungus B is present.
D) Its biomass is greatest when AM fungus C is present.
E) Its biomass is greatest when all AMF are present.