c) expression of genes and production of specific proteins.
Explanation:
Estrogen is a lipid-soluble steroid hormone that diffuses through the lipid bilayer of the plasma membrane of its target cell. The hormone binds to its nuclear receptor and receptor-hormone complex then alters the expression of particular genes.
It triggers transcription of specific DNA sequences into mRNA which in turn enters the cytoplasm and serves as a template for synthesis of specific proteins.
Estrogen is the female sex hormone and stimulates development of secondary sexual characters in females as well as required for maturation of egg.
Parents and first child have free earlobes so it must be dominant trait while attached is recessive. In order to have a recessive trait as seen in the second child, the parents must have a recessive allele.
