In a previous post the term autosomal recessive is mentioned. What is the inheritance factor for an autosomal recessive, ie: affected x carrier, carrier x carrier, normal x carrier?

Best to read Control of Canine Genetic Diseses by George A. Padgett, DVM. The book will answer your question.

It's a simple Punit square.

Normal X Normal = 100% Normal
Normal X Carrier = 50% Normal and 50% Carrier
Affected X Affected = 100% Affected
Affected X Carrier = 50% Affected and 50% Carrier
Affected X Normal = 100% Carrier
Carrier X Carrier = 50% Carrier 25% Affected 25% Normal

Sorry I was typing quickly.

Affected X Carrier = 75% Affected and 25% Carrier

Sharon, are you sure about the affected x carrier = 75% affected 25% carrier?

Did the Punnett square using gene A.
Aa - carrier
aa - affected

a a
A Aa Aa
a aa aa

It gave me 1/2 Carrier and 1/2 Affected

If I did this wrong, my Genetics test today is going to be a problem.

I do get confused with some of the terminology however if you are referring to something like a PRA test, according to Optigen if you breed Affected to Carrier you do get in any given puppy 50% chance of Affected, 50% chance of Carrier. If I'm way off and you're speaking of something else, sorry.

I think a disease is autossomal recessive when you breed "carrier x carrier" and results "affected dog". Am I right or wrong?

I don't take Genetics exams- I write them and grade them! You are correct- affected X carrier is Aa X aa and would give 50% Carrier and 50% affected.

A recessive allele must be inherited from both parents in order to be expressed. A dominant allele need be inherited from only one parent. If an individual has a dominant allele and a recessive allele )ie a carrier), the dominant one will be expressed. The recessive will not be expressed but can be passed on to the offspring.

Autosomal means that the gene is not on the X (or Y) chromosomes. Most genes are autosomal. X linked genes have a different inheritance pattern because males have only one X chromosome, inherited from their mother. Females have two X chromosomes and therefore two alleles for every trait. Y linked genes are very rare, but would be passed on from father to son.

No you are correct - my quick typing was right! Then my mind was absent thinking 50%/50% for the dominant gene and 100% for the recessive giving a 75/25

autosomal means - any chromosome other than the sex chromosome

recessive is when the trait is only expressed if passed on by both parents. It takes two to tango.

You were thinking of phenotypes in a carrier X Carrier cross. 75% would be normal in phenotype and 25% would be affected.

thank you!!!!