Achild has sickle-cell disease (ss) but neither parent is ill. what must be true of her parents’ genotypes? the father is heterozygous; the mother is normal. one parent has two recessive alleles. both parents are heterozygous carriers. the mother is heterozygous; the father is normal.

Both parents are heterozygous carriers.

Explanation:

Both parents are heterozygous carriers. Sickle Cell Anaemia is usually referred to as a recessive condition since an individual must have two copies of the sickle gene in order to have the disorder.

Since neither of the parents is ill, both of them must be heterozygous carriers for the child to have the disorder

answer; /// i believe that the correct answer is; ///a combination of the birth and death

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.