An animal that inherits a copy of the stress gene from both parents is known as what?

The correct identification of an animal that inherits a copy of the stress gene from both parents involves understanding genetic notation. When examining the choices, "nn" represents an individual that has received the recessive allele for the stress gene from both its mother and father, resulting in a homozygous recessive genotype.

In this genetic context, the 'n' signifies the allele associated with the stress gene, and having two copies of this allele (nn) indicates that the animal possesses the genetic makeup that may lead to expressing stress-related traits or conditions linked to that gene.

The other options, such as "NN" and "Nn," refer to different combinations of alleles. "NN" would indicate that the animal has inherited the dominant allele from both parents, while "Nn" represents a heterozygous condition, with one dominant and one recessive allele. "nnP" is not standard notation for indicating homozygosity for the stress gene and may imply some additional variable that does not clarify the inheritance of the stress trait.

Thus, "nn" accurately describes the situation where both inherited alleles are the recessive form, leading to the expression of traits associated with that genetic condition.