Both prokaryotic and eukaryotic cells have a nucleus and ribosomes.
A) a common ancestor
Homologous structures are structures that are similar in related organisms. There is a basic pattern of bones which can be inherited from a common ancestor
Meiosis only occurs in reproductive cells, as the goal is to create haploid gametes that will be used in fertilization. Meiosis is important to, but not the same as, sexual reproduction. Meiosis is necessary for sexual reproduction to occur, as it results in the formation of gametes sperm and eggs.