Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.

Let me give you an example: Sentence1: pesticides cause pollution.
Sentence2: pollution can harm animals.
The answer to this example can be: pollution.
Here is why: The word "pollution" is common to Sentence1 and Sentence2. So, it's a good answer.

OK. solve this:
Sentence1: Cells are the basic units of the structure and function of living things.
Sentence2: Cells make up the structure and function of plants and animals.
Answer:
Cells