Questions & Answers

Ribosomes are the site of
(a)DNA Replication

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Hint:Ribosomes are ribonuclear proteins that contain rRNA and r-proteins acting as a small migrating factory that aids in the polymerization of amino acids to form a polypeptide.

Complete answer:
The process of DNA replication and transcription takes place in the nucleus. Ribosomes, present in the cytoplasm are the site for translation (protein synthesis) of mRNA into an amino acid sequence of the polypeptide. Translocation is the step involved in the elongation cycle of protein synthesis that includes the transfer of tRNA from the A site to the P site of the ribosome. Repression is the inhibition of gene expression which can target any of the molecules (DNA, RNA, or protein). The site of repression depends on the site of the molecule to be targeted.

Additional information:
Ribosomes are present in both prokaryotes and eukaryotes. The ribosome is organized into a small and a large subunit. Prokaryotic ribosomes are 70S particles comprising a small, 30S subunit and a large, 50S subunit. The 30S subunit is made up of 16S rRNA and 21 proteins; and the 50S subunit is made up of 23S rRNA, 5S rRNA, and 34 proteins. Eukaryotic ribosomes are 80S particles comprising a small, 40S subunit and a large, 60S subunit. The 40S subunit is made up of 18S rRNA and 33 proteins; and the 50S subunit is made up of 28S rRNA, 5.8S rRNA, 5S rRNA, and 50 proteins.
Ribosomes can occur both freely in the cytosol, i.e. not attached to any organelle, or attached to the membrane of the rough endoplasmic reticulum as in eukaryotic cells.

So, the correct answer is ‘Translation’.

The sizes of the subunits and their component ribosomal RNAs (rRNAs) are described by a sedimentation coefficient 'S' dependent on the relative molecular mass and shape (S stands for Svedberg unit).