Tuskless elephants are only observed in females. The daughters of tuskless females are roughly a 1 to 1 ratio of tuskless vs two-tusked. The daughters of two-tusked females are almost exclusively two-tusked.

a. What is the inheritance mechanism of this tuskless trait? X-linked dominant, X-linked recessive, Y-linked recessive, autosomal recessive, or autosomal dominant

b. Scientists also observed a peculiar sex bias: 65.7% of offspring of tuskless mothers are females, while this sex bias is not observed in the offspring of two-tusked mothers. What can you infer from this sex bias? The wildtype allele is lethal in males, the tuskless allele is lethal in females, the tuskless allele is lethal in males, the wildtype allele is lethal in females

c. A considerable portion of the daughters of tuskless mothers display an unusual phenotype: unilateral tusklessness. Those individuals only have a tusk on one side. What is the most likely explanation for this observation: non-disjunction of the X chromosome of heterozygous individuals, new mutations in the gene affect tusks, non-disjunction of the Y chromosome of heterzygous individuals, random X chromosome inactivation in homozygous individuals, random X chromosome inactivation in heterozygous individuals