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: Algae have varied life cycles. 
Sentence2: primitive green plants have varied life cycles.
Answer:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
cycles