What is a method to account for false positive results?

What genes encode the classical MHC I proteins? 

In a family of 4 siblings, 2 daughters and 2 sons, all show varying signs of an eye disease. They all share the same father and the same mother.  Neither parent has the disease.  Which of the following best explains this scenario?

In a particular species of mice, the yellow coat color is dominant to black coat color, but the homozygous dominant genotype results in embryonic lethality. When two yellow mice are mated, what proportion of their litter of baby mice will have yellow coat colors?

A form of Rickets is due to an X-linked dominant allele. Alice does not have Rickets, but her spouse Walter does have Rickets. What is the percent chance that their next child will be a daughter with Rickets? 

A DTC result indicates that I have a 12% overall risk for osteoporosis based on my having a SNP that accounts for a 3% relative risk for osteoporosis. What is the general population risk for osteoporosis? 

What is a method to account for false positive results?

What genes encode the classical MHC I proteins? 

In a family of 4 siblings, 2 daughters and 2 sons, all show varying signs of an eye disease. They all share the same father and the same mother.  Neither parent has the disease.  Which of the following best explains this scenario?

In a particular species of mice, the yellow coat color is dominant to black coat color, but the homozygous dominant genotype results in embryonic lethality. When two yellow mice are mated, what proportion of their litter of baby mice will have yellow coat colors?