In dogs, wire hair is due to a dominant gene, and smooth hair to its
recessive allele. Two wire haired dogs produced a male pup which is
wire haired. To find out most quickly whether her carries the gene for
smooth hair,what should the owner do?

Hi Jennifer1000,

Think of it this way:

Call the dominant gene W and the recessive w.  We know that the dog is
either Ww or WW (because wire-hairedness is dominant, it will present
the dominant phenotype regardless of heterozygosity).

If the dog is WW, ALL offspring will be wirehaired.  Again, dominant allele.
If the dog is Ww and is bred to a female dog (just to be PC) that is
Ww, you will have 3/4s of the offspring wirehaired (1/4 WW, 1/2 Ww)
and 1/4th smooth (ww).
If the dog is Ww and is bread to a female dog that is ww, you will
have 1/2 wirehaired (Ww) and 1/2 smooth (ww).

It's all down to chance how the alleles sort out, but statistically
you're more likely to get a (ww) puppy from the Ww by ww mating.  So,
the owner should mate his dog with a smooth haired female.

By the way, the hairedness of the dog's parents doesn't help you much here.

Here are some links to genetics primers on the web:

Mendelian Genetics
http://www.ndsu.nodak.edu/instruct/mcclean/plsc431/mendel/mendel1.htm

Genetics: Introduction and Analyzing Crosses
http://web.mit.edu/esgbio/www/mg/crosses.html

Introduction to Mendelian Genetics
http://www.blc.arizona.edu/courses/181gh/rick/genetics1/default.html

Mendel's Law & Mendelian Genetics
http://www.biology-online.org/2/5_mendelian_genetics.htm

I "stole" these from a previous question that I answered, but you can
find them by doing a search of the Google database for "Mendelian
Genetics".

- Librariankt

not sure but i thik the only would you could actually get a check is
to get a blood test. now if you know the genetics of the parents then
you could guess what whether or not the pup is a carrier.

You could cross the pup with a smooth haired female. If the wire
haired male is a carrier of the smooth hair gene then about 50% of the
offspring will have smooth hair. If he is not, then 100% of the
offspring will be wire-haired.