Chick with rose comb hatched from parents with single combs... how?

[maddogdodge]

A lot of my flock are random X breeds that I keep as pets, I've been trying to x my favourite rooster (Mr. Roo) with my favourite hen (Fluffy) for quite a while now! Finally had success, a lovely little healthy white chick hatched. It's now about a week old and I noticed today that it has a rose comb which really surprised me!! As I have no idea of the history of either of the parents it's hard to know where this came from... I guess it's some kind of throwback?

Someone told me that rose combs are dominant so cannot be a throwback... is this correct?

Here's some photos...

The chick in question.


Dad - Mr. Roo


Mum - Fluffy

 

[ChickenCanoe]

Since they're all mutts, virtually anything can show up.

You can even get sports in any pure breed from time to time.

 

[maddogdodge]

Since they're all mutts, virtually anything can show up.

You can even get sports in any pure breed from time to time.

That's what I thought but someone told me that because rose comb is a dominant gene that neither of the parents could have that gene otherwise they'd have rose combs...

 

[Rns]

Is it a rooster or pullet?