Which of these cellular structures would be found in all living cells across all domains on earth and can indicate common ancestry?

The question is incomplete as it does not have the options which are:

A) Chloroplasts

B) Cilia

C) MItochondria

D) Ribosomes

Answer:

D) Ribosomes

Explanation:

The organism can be classified as prokaryotes and eukaryotes based on their origin. The prokaryotes are the unicellular organism which was formed in the primitive time when the life was beginning to evolve. The eukaryotes were later evolved from the prokaryotes.

Observing the cytology of the cell shows that the organelle present in both the eukaryotes and prokaryotes is the ribosome which is associated with the synthesis of proteins from the mRNA.

Thus, the ribosome is the correct answer.