Problem: Certain alleles are still inherited and remain in the human population even though they lead to early death of the individual. An example of such an allele is the allele causing Huntington's disease. You would think that alleles leading to early death would be lost to the population. Why are these alleles still present in the human gene pool?
a. These alleles are the result of random mutations that occur due to environmental affects.
b. These mutations occur as a result of mitosis so the allele is not inherited but instead just occurs in different individuals.
c. All diseases have nothing to do with genetics but are caused by environmental contamination.
d. Generally these people do not show signs until they have already entered reproductive age and so the alleles are passed on unknowingly.