SSC Selection Post 2025 PYQ — Question 4

Correct Answer

DNA is converted into RNA

Explanation

Transcription is the fundamental biological process in which a specific segment of DNA is copied into RNA (specifically messenger RNA, or mRNA) by the enzyme RNA polymerase. This process occurs inside the nucleus of eukaryotic cells. During transcription, the DNA double helix unwinds, and one strand acts as a template. The RNA polymerase reads this template strand and matches complementary RNA nucleotides (using Uracil instead of Thymine) to construct a single-stranded RNA molecule. This RNA molecule carries the genetic code out of the nucleus into the cytoplasm, acting as an intermediary blueprint for building proteins.

Key Points

DNA replication into identical copies is a separate process called Replication, which happens before a cell divides to ensure each new cell gets a full set of DNA.

RNA being translated into proteins is the next step in gene expression, known as Translation, which takes place in the cytoplasm at the ribosomes.

Protein folding into functional shapes occurs after translation, where the newly formed amino acid chain twists and folds into a specific three-dimensional structure to become biologically active.

Important Questions and Answers

Question: Which main enzyme is responsible for catalyzing the synthesis of RNA from a DNA template during transcription?

Answer: RNA polymerase is the primary enzyme responsible for this process.

Question: Which nitrogenous base replaces Thymine (T) in the newly formed RNA strand during transcription?

Answer: Uracil (U) replaces Thymine in RNA and pairs with Adenine (A).