Both parents are heterozygous for the huntington's allele. what is the chance that their child will not have huntington's disease

25% or 1/4

Explanation:

The cross in this question involves a gene coding for the possession or not of Huntington's disease in humans. The dominant allele is denoted by (H) while the recessive allele is denoted by (h). The possession of the dominant allele by an individual means the possession of the Huntington's disease.

In a cross between two heterozygous parents i.e. combination of both dominant and recessive alleles (Hh). Four possible offsprings will be produced with genotypes HH, Hh, Hh and hh.

The genotypes HH, Hh and Hh will phenotypically possess the Huntington's disease while the hh genotype will not possess the Huntington's disease. Hence, the chance of having a child without the disease is 1/4 or 25%.

who knows

explanation:

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.