What best explains how the long -haired phenotype can appear in the offspring of two short-haired dogs? a)only recessive alleles are inherited for homozygus parents b)dominant alleles grow weaker as they are passed from parents to offspring c)only the parent with a dominant alllele can pass the allele to offsring in sexual reproduction d)a heterozygous parent has an equal chance of passing either the dominant allele or the recessive allele to offsring.

Oh god! Intresting question.     I think its  the answer is      A only recessive alleles are inherited for homozygus parents .The L Locus (Long Hair/ Fluffy) trait test reliably determines if a dog has one of the following genotypes at the L locus:

Sh/Sh  

A dog carries two copies of Sh which results in short hair. This dog will pass on Sh to 100% of its offspring.

Interpretation: Shorthaired

Sh/Lh  

A dog carries one copy of the Sh and one copy of Lh which results in short hair. This dog will pass on Sh to 50% of its offspring and Lh to 50% of its offspring.

Interpretation: Shorthaired (carries longhaired)

Lh/Lh  

A dog carries two copies of Lh which results in long hair. This dog will pass on Lh to 100% of its offspring.

Interpretation: Longhaired

Detailed Summary

The L Locus impacts canine hair length as a result of a DNA variant in the FGF5 gene that prevents FGF5 from functioning as a hair growth termination signal in the hair follicle.

Testing Tips

Genetic testing of the FGF5 gene will reliably determine whether a dog is a genetic Carrier of long hair. Long hair is inherited in an Autosomal Recessive fashion, meaning that two copies of the Lh variant are required to produce long hair. Dogs with two copies of the Lh variant of FGF5, therefore, have long hair due to the lack of the hair growth termination signal. Dogs with one copy of Lh or no copies of Lh will have short hair.

There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.

The rest is just notes i think. Hope it helped you!

format change of dna.  

it's     c       this is a cell (b) with a nucleus (c) containing dna (a). the dna is organized into chromosomes (d). a section of the chromosome that codes for a trait is called a gene (e).