The point of a topic sentence is twofold. First, the topic sentence must support the thesis statement. Second, the topic sentence must lead the paragraph it begins. Therefore, topic sentences are very important when deciding how to phrase them appropriately to ensure that they function well.
Without a more specific understanding of what your thesis may be, you have a couple options here.
Thesis focuses upon characters who perpetuate prejudice:
Mayella Ewell's court case perpetuates prejudice by presenting Tom as a rapist.
Walter Cunningham Sr.'s mob actions also perpetuate prejudice by trying to lynch Tom prior to his trial.
Lula, a woman at Calpurnia's church, perpetuates a different kind of prejudice by trying to keep the Finch children out of the black church.
Thesis focuses upon events which perpetuate prejudice:
The treatment of Tom Robinson, during his trial, illustrates the prejudice of the town.
Another event which perpetuates prejudice in the novel is the treatment of Boo Radley.
(The entire section contains 3 answers and 638 words.)