Answer: a. tRNA
Explanation: The transference RNA is a nucleic acid that participates of the protein synthesis. tRNA is a small RNA with folding as a trefoil. The tRNA has a site where aminoacid is loaded and a anticodon site that is complementary to the codon in the mRNA, ensuring the proper aminoacid sequence in the resulting polypeptide.
C. The cell took in another ancient prokaryotic cell, which began living inside it.
Vacuoles are essentially sacs surrounded by a membrane. They are used by cells as temporary storage sites. They often store food, enzymes, and other materials needed by the cell, and some vacuoles store waste products.
The common characteristic of those two organisms is hard spherical shells (exoskeleton).
Foraminiferans are single cell marine eukaryotes divided into granular endoplasm and transparent ectoplasm. Foraminiferans are enveloped with tests, hard shells, usually composed of calcium carbonate (sometimes from organic compounds or silica).
Coccolithophore is a unicellular, eukaryotic alga with special calcium carbonate plates (or scales) of uncertain function (coccoliths). Each unicellular alga is enclosed in its own collection of coccoliths, the which make up its exoskeleton- coccosphere.
