Select the most correct statement regarding nucleic acids.
RNA is a long, single-stranded molecule made up of the bases ??,??,??, ?and ??.
RNA is a long, single-stranded molecule made up of the bases ??,??,??, ?and ??.
Three forms exist: DNA, RNA, and tDNA.
tDNA is considered a “molecular slave” of DNA during protein synthesis.R
The Correct Answer and Explanation is :
The most correct statement is:
RNA is a long, single-stranded molecule made up of the bases adenine (A), uracil (U), cytosine (C), and guanine (G).
Explanation:
RNA (ribonucleic acid) is a single-stranded molecule that plays a crucial role in various biological processes, most notably protein synthesis. RNA is similar to DNA (deoxyribonucleic acid) but differs in several key aspects, particularly its sugar component and the base used to pair with adenine.
- RNA Structure:
- RNA consists of a chain of nucleotides, each containing a sugar (ribose), a phosphate group, and a nitrogenous base.
- The nitrogenous bases found in RNA are adenine (A), uracil (U), cytosine (C), and guanine (G). Uracil replaces thymine (which is present in DNA).
- RNA is typically single-stranded, but it can fold back on itself to form secondary structures, such as hairpins and loops.
- Base Pairing:
- In RNA, adenine (A) pairs with uracil (U), and cytosine (C) pairs with guanine (G). This is different from DNA, where adenine pairs with thymine and cytosine with guanine.
- Types of RNA:
- There are three main types of RNA: mRNA (messenger RNA), tRNA (transfer RNA), and rRNA (ribosomal RNA). These work together in the process of protein synthesis.
- mRNA carries genetic information from DNA to the ribosome.
- tRNA helps translate the genetic code from mRNA into amino acids during protein synthesis.
- rRNA is a key structural component of ribosomes, which are the sites of protein synthesis.
- Distinction from DNA:
- DNA is double-stranded, while RNA is single-stranded.
- DNA contains the sugar deoxyribose, while RNA contains ribose.
- DNA uses thymine (T), while RNA uses uracil (U) in its base pairing.
Therefore, the statement correctly describes RNA as a single-stranded molecule consisting of the bases A, U, C, and G, and is critical for processes like transcription and translation in the synthesis of proteins. The other statements either contain incorrect information or are irrelevant in this context.