which nucleic acid statement is true?

A. mRNA codes for DNA
B. mRNA codes for protein
C. tRNA makes amino acids
D. tRNA makes lipids
I think B

To determine which nucleic acid statement is true, let's review the functions of each type of nucleic acid.

A. mRNA (messenger RNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm. mRNA is involved in protein synthesis but does not code for DNA itself, so it is not the correct answer.

B. mRNA codes for proteins. This statement is correct. During the process of protein synthesis, mRNA acts as a template for the production of proteins by providing the instructions for the sequence of amino acids.

C. tRNA (transfer RNA) is responsible for bringing the correct amino acids to the ribosomes during protein synthesis. tRNA does not make amino acids itself but helps in their assembly into proteins. So, this statement is not true.

D. tRNA does not make lipids. Lipids are a different class of biomolecules and are not directly synthesized by tRNA.

Therefore, based on the explanations above, the correct answer is B. mRNA codes for protein.