Question

Which statement is true? RNA codes for proteins which code for ​ DNA ​. ​ DNA ​codes for RNA which codes for proteins. ​ DNA ​codes for proteins which codes for RNA . ​ RNA ​codes for ​ DNA ​which codes for proteins.

Answer 1

Answer:

Genetic code

The genetic code is the set of rules by which information encoded in genetic material (DNA or RNA sequences) is translated into proteins (amino acid sequences) by living cells.

Specifically, the code defines a mapping between tri-nucleotide sequences called codons and amino acids; every triplet of nucleotides in a nucleic acid sequence specifies a single amino acid.

Because the vast majority of genes are encoded with exactly the same code, this particular code is often referred to as the canonical or standard genetic code, or simply the genetic code, though in fact there are many variant codes; thus, the canonical genetic code is not universal.

For example, in humans, protein synthesis in mitochondria relies on a genetic code that varies from the canonical code.

The genome of an organism is inscribed in DNA, or in some viruses RNA.

The portion of the genome that codes for a protein or an RNA is referred to as a gene.

Those genes that code for proteins are composed of tri-nucleotide units called codons, each coding for a single amino acid.

Each nucleotide sub-unit consists of a phosphate, deoxyribose sugar and one of the 4 nitrogenous nucleotide bases.

The purine bases adenine (A) and guanine (G) are larger and consist of two aromatic rings.

The pyrimidine bases cytosine (C) and thymine (T) are smaller and consist of only one aromatic ring.

In the double-helix configuration, two strands of DNA are joined to each other by hydrogen bonds in an arrangement known as base pairing.

These bonds almost always form between an adenine base on one strand and a thymine on the other strand and between a cytosine base on one strand and a guanine base on the other.

This means that the number of A and T residues will be the same in a given double helix as will the number of G and C residues.

In RNA, thymine (T) is replaced by uracil (U), and the deoxyribose is substituted by ribose.

Answer 2

The correct statement is - DNA ​codes for RNA which codes for proteins.

Central dogma:

• The process by which the instructions in DNA are turned into a functioning product is known as the 'Central Dogma.'
• Francis Crick, the discoverer of the structure of DNA, initially proposed it in 1958.
• The "central dogma" is the process of creating protein from DNA.
• However, it is not a single step, but rather two: transcription and translation, with an intermediary component called RNA.
• DNA → RNA → Protein.
• DNA codes for RNA, which codes for proteins, according to the basic dogma of molecular biology.
• The Central Dogma discusses the critical functions of messenger RNA, transfer RNA, and ribosomal RNA in the protein-building process.

Genetic code:

• The genetic code is made up of three-letter nucleotide combinations called codons, each of which corresponds to a different amino acid or stop signal.
• Francis Crick and his colleagues introduced the notion of codons in 1961.
• There are two forms of genetic coding.
• The genetic code can be produced using RNA or DNA codons.
• RNA codons are found in messenger RNA (mRNA) and are the codons that are actually "read" during polypeptide synthesis (the process called translation).

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