Hint: The primary function of mRNA is to act as an intermediary between the genetic information in DNA and the amino acid sequence of proteins. mRNA contains codons that are complementary to the sequence of nucleotides on the template DNA and direct the formation of amino acids through the action of ribosomes and tRNA.
The correct option is a) provide a specific binding site for a series of specific t-RNA molecules.
In this question we have asked about the function of mRNA or messenger RNA. As we already mentioned the function of mRNA is carrying information from DNA to synthesize protein but we do not have both options in the question. So, let's discuss the process of protein synthesis. Protein synthesis occurs in 3 stages.
1. Initiation: Ribosomal subunits bind to mRNA.
2. Elongation: The ribosome moves along the mRNA molecule linking amino acids and forming a polypeptide chain.
3. Termination: The ribosome reaches a stop codon, which terminates protein synthesis and releases the ribosome.
During transcription, DNA is used as a template to make a molecule of messenger RNA (mRNA). The molecule of mRNA then leaves the nucleus and goes to a ribosome in the cytoplasm, where translation or protein synthesis occur. It contains an amino acid attachment site on one end and a special section in the middle loop called the anticodon site. The anticodon recognizes a specific area of mRNA called a codon. tRNA translates the message within the nucleotide sequence of mRNA to a specific amino acid sequence. These sequences are joined together to form a protein. Multiple ribosomes attached to the mRNA bearing nascent growing polypeptide chains and synthesize the multiple copies of a protein simultaneously.
So, our first option is to provide a specific binding site for the series of specific tRNA molecules, which is absolutely right as we already mentioned that tRNA contains two sides, one site binds to amino acid and second one by two mRNA. Option B holds a group of ribosomes together, which is wrong because multiple ribosomes attach to mRNA but it does not hold multiple ribosomes. Our next option is to transfer the genetic code to ribosomal RNA, which is wrong because it does not transfer genetic code to ribosomal RNA it transfers genetic information from DNA to tRNA for making protein. Option D is to transfer the genetic code to DNA, which is also wrong because it does not transfer the genetic information to DNA but carries information from DNA and transfers it to tRNA for the synthesis of protein.
Therefore, the correct option is, a)
Note: mRNA carries genetic information, rRNA or ribosomes synthesize protein in the cell and tRNA is an adaptor for mRNA. Messenger RNA (mRNA) molecules carry the coding sequences for protein synthesis and are called transcripts; ribosomal RNA (rRNA) molecules form the core of a cell's ribosomes (the structures in which protein synthesis takes place); and transfer RNA (tRNA) molecules carry amino acids to the ribosomes during protein synthesis.