Chicks a few weeks old have a line of bumps for the single comb, but rose comb chicks' heads are smoother because the rose comb takes a little longer to grow.
I don't think it affects your chickens unless you show them at fair or some other place, though I have heard that some combs don't get frostbitten.
Here are some tips:
-boys have pointed feathers than girls
-boys are normally more bold
-by 2 months boys will have larger, redder combs and thicker legs
-2-4 months boys will start developing saddle and hackle feathers
Apreachiate that. I'm telling you this breed is tuff! I found out that three are pullets and one is a Cockerel. They all had the same combs (kinda) same feather patterns but only one crows lol and is definitely flashier.