Figure 38.2 -The IRT1 Gene Is Responsible for Most of the Iron

Figure 38.2

-The IRT1 gene is responsible for most of the iron uptake activity in roots (Vert et al. ,Plant Cell 14 [2002]:
1223-33) .To determine the specificity of the IRT1 transporter in Arabidopsis plants,researchers measured the concentration of manganese,zinc,copper,and cobalt contained in wild-type and irt1-1 mutant plants.What conclusions about IRT1 specificity can you draw from the above data?

A) Under iron-deficient conditions,IRT1 is highly specific for Fe.
B) Under iron-deficient conditions,IRT1 is important for the transport of iron and copper.
C) IRT1 is important for the transport of iron and copper independent of iron concentration.
D) Under iron-deficient conditions,IRT1 is necessary for the transport of iron,zinc,manganese,and cobalt.
E) IRT1 participates in the transport of iron,zinc,manganese,and cobalt independent of iron concentration.