你就是不查词典。自己查一下动词ground, 答案就出来了。

There are consumer fears of toilet paper running out grounded in reality ?

这是一个陈述问句，即陈述句句末用问号。of toilet paper running out为介词短语作fears的定语。grounded in reality=based on reality,为consumer fears of toilet paper running out这个名词词组的定语。