Are these the same: "...like the real thing" vs "...like the real one."

Question

The following sentence is from a scientific content which talks about producing artificial food and how similar they are to the real ones.

"This salmon fillet didn't come from the sea. It was grown in a lab to look just like the real thing."

When I think about the part of the sentence "...like the real thing.", I wondered if -instead of it- I could say "....the real one". And they seem to have same meaning, don't they?

So, my question is: Is there any difference between "...the real thing" and "....the real one." in the above sentence?

Answer 1

the real one doesn't really make sense here. The definite article in the real one makes it sound like there is only one specific salmon fillet that is real, and that obviously doesn't make sense. You would only say the real one if you had two fillets in front of you, one artificial and one real, and then you could say "The artificial one looks like just like the real one", but if you are not referring to one specific fillet, the real one doesn't make sense.

the real thing is an idiomatic phrase meaning "something that is genuine or authentic", which is why it makes sense here.

You could also say a real one, since the indefinite article implies "one of many possible real ones".