Question

this passage describes the myotonia congenita trait in goats: myotonia congenita is a condition that causes temporary muscle stiffness. when goats with myotonia congenita attempt to run from a resting position, their leg muscles often stiffen, causing them to fall over. because of this behavior, these goats are referred to as fainting goats. myotonia congenita is also found in other mammals, including horses, cats, and humans. in a group of goats, some individuals have myotonia congenita and others do not. in this group, the gene for the myotonia congenita trait has two alleles. the allele m is for having myotonia congenita, and the allele m is for not having myotonia congenita. hickory is a goat from this group. hickory’s phenotype for the myotonia congenita trait is having myotonia congenita. hickory’s genotype for the myotonia congenita gene is mm. based on this information, complete the following statement. hickory is for the myotonia congenita gene. heterozygous homozygous

Explanation:

The term 'heterozygous' refers to having two different alleles for a gene. Since Hickory's genotype for the myotonia congenita gene is $Mm$ (two different alleles $M$ and $m$), Hickory is heterozygous. A homozygous individual would have two of the same alleles (either $MM$ or $mm$).

Answer:

heterozygous