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.

[Q]: Sentence1: a mutation in the sex cells of a parent can cause a new trait to appear in the parent 's offspring. 
Sentence2: Traits are initiated by mutation and recombination.
[A]: mutation


[Q]: Sentence1: Chromosomes are the form of the genetic material of a cell during cell division. 
Sentence2: Microtubules move the genetic material of a cell during cell division.
[A]: cell


[Q]: Sentence1: Puberty is the period during which humans become sexually mature. 
Sentence2: humans become sexually mature during adolescence.
[A]:
become