Final answer:
The new ribonucleotide in RNA attaches at the 3' hydroxyl group of the ribose sugar. It takes three nucleotides to code for a single amino acid, forming what is known as a codon. A mutation in the amino acid coding region is most likely to be damaging to the cell.
Step-by-step explanation:
The part of the ribose sugar where a new ribonucleotide will attach in an RNA molecule is at the 3' hydroxyl group. When a new nucleotide is added to a growing RNA chain, the phosphate group of the new nucleotide forms a bond with the 3' hydroxyl group of the sugar of the last nucleotide in the existing chain, therefore the correct answer is (b) 3. This process extends the chain in a 5' to 3' direction. The 3' hydroxyl group of the ribose sugar in RNA is essential for linking nucleotides together during the process of RNA synthesis.
The mutation most likely to be damaging to the cell would be in the region where the amino acid coding sequence (also known as the coding region) is located. A mutation in the coding region can lead to changes in the resulting protein, potentially affecting its function. Without knowing the details of the regions (1-5), we cannot definitively answer which mutation would be damaging. Generally, mutations in the coding region (likely region 2) are most problematic.
It takes three letters, or nucleotides, of an RNA molecule, in sequence, to provide the code for a single amino acid. This sequence of three nucleotides is known as a codon, and the correct answer is (C) 3.
Three components comprise a nucleotide: a nitrogenous base, a pentose sugar, and one or more phosphate groups. In RNA, the sugar is ribose, which is attached at the 1' carbon to the base and at the 5' carbon to the phosphate group.