[Mr_Sandman]

I was going to say it's a setting specific detail. If the morph ability has a magic, psionic, or pseudo-science explanation, there's no reason that unseen details wouldn't be copied as well.

Then I remembered that there is a limitation that introduces flaws to morph so that it can be detected, so I changed my mind and would rule that a perfect copy, undetectable by external inspection, is the default for morph, and if there are any visible differences it is a limitation.