Three unaffected children and one with Gaucher disease are born to two healthy parents. If "M" is the allele for the healthy gene and "m" for Gaucher disease, what are the parents' genotypes?

If one parent is homozygous for a recessive mutant allele and the other is a heterozygous carrier for a recessive mutant allele, what is the chance that their child will inherit the condition?

If the haploid number of chromosomes in an organism is 15 and each diploid nucleus contains 2 ng of DNA in the G1 phase, what is the amount of DNA in a diploid nucleus during the G2 phase?

Suppose that in an insect, unfertilized eggs (n) develop into males via parthenogenesis. On the contrary, fertilized eggs (2n) in the homozygous condition result in males, whereas fertilized eggs (2n) in the heterozygous condition result in females. Assume that a XY female mates with a X male and produces 60% unfertilized eggs and 40% fertilized eggs. Identify the ratio of male to female offspring in such a case.