How does the lottery affect Tess Hutchinson and her family at the end of the story? How is this a good example of how plot can influence characters?  

At the end of the story Tess is stoned.... she is dead. Thus her husband is left a widow, and her children are motherless. Likely, they've also witnessed her death.... what a trauma.

The plot is influenced by the fact that Tess knows what's going to happen at the conclusion of the lottery, and we as readers do not. We don't understand her arguments, pleas, or panic, until the stones are picked up. For most of us, the end of the story is a complete shock.... it's horrific. None-the-less, this is also storytelling at its best.