Turn the given fact into a question by a simple rearrangement of words. This typically involves replacing some part of the given fact with a WH word. For example, replacing the subject of the provided fact with the word "what" can form a valid question. Don't be creative! You just need to rearrange the words to turn the fact into a question - easy! Don't just randomly remove a word from the given fact to form a question. Remember that your question must evaluate scientific understanding. Pick a word or a phrase in the given fact to be the correct answer, then make the rest of the question. You can also form a question without any WH words. For example, "A radio converts electricity into?"
One example: Fact: pesticides can harm animals.
Solution is here: What can harm animals?
Explanation: It's a good question because it is formed by simply replacing the word "pesticides" with "what".

Now, solve this: Fact: Fertilization occurs when a male gamete and an egg fuse to form a diploid zygote.
Solution:
Fertilization occurs when an egg and what join together to form a diploid zygote?