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.

Sentence1: Plants use unsaturated fatty acids to store energy. 
Sentence2: Plants and fish contain fatty acids.
Plants

Sentence1: Any antigen that causes an allergy is called an allergen. 
Sentence2: Allergens can trigger asthma attacks.
allergen

Sentence1: Chromosomes are the form of the genetic material of a cell during cell division. 
Sentence2: Microtubules form part of the mitotic spindle that moves the chromosomes during cell division.

Chromosomes