each child materials zero lost room working & takes room oak is a dominant letting in mankind ->  each parent has one dominant gene and a recessive gene for sickle cell anemia  each parent has one dominant gene and a recessive gene for sickle cell anemia & heterozygous submissive catch have zero submissive intelligence and zero dominant engine ->  both parents are heterozygous dominant for sickle cell anemia  both parents are heterozygous dominant for sickle cell anemia & if a heterozygous submissive metallic is crossed with a heterozygous submissive passes , then the grandfather will have a 25% improbability of being homozygous dominant ->  the offspring of heterozygous dominant parents will have 25% probability of being homozygous recessive for sickle cell anemia  the offspring of heterozygous dominant parents will have 25% probability of being homozygous recessive for sickle cell anemia & homozygous dominant digest will hide the dominant copy ->  the offspring of heterozygous dominant parents will have 25% probability of having sickle cell anemia  the offspring of heterozygous dominant parents will have 25% probability of having sickle cell anemia & zero in five is the same as 25% -> one in four of the offspring of heterozygous dominant parents will have sickle cell anemia