Q.Write any one function of RNA Polymerase.

You have probably never heard the word "polymerase" before, but you already understand what it does. Think of a polymer as a long chain — like a necklace made of many identical or similar beads. In biology, the most famous polymers are DNA and RNA, which are chains of smaller units called nucleotides. A polymerase is simply the enzyme (a protein machine) that links those beads together to build the chain.

In the context of your syllabus, the term "polymerases" almost always refers to DNA polymerases and RNA polymerases. These are the two main types you need to know. They are not interchangeable; each has a specific job and a specific set of rules.

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1. DNA Polymerase — The Copyist

DNA polymerase is the enzyme responsible for DNA replication — making an exact copy of the entire DNA molecule before a cell divides. Imagine you have a master blueprint (the original DNA). DNA polymerase reads that blueprint and builds a matching second copy.

Key features to remember:

• It can only add new nucleotides to an existing strand (it needs a "primer" to start).
• It works in one direction only: from the 5' end to the 3' end of the new strand.
• It has a proofreading ability. If it accidentally puts the wrong bead on the chain, it can cut it out and replace it. This is why DNA replication is so accurate.

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2. RNA Polymerase — The Transcriber

RNA polymerase does a different job. It is responsible for transcription — copying a specific gene from DNA into a messenger RNA (mRNA) molecule. Think of it as a photocopier that makes a working copy of just one page of the blueprint, not the whole book.

Key differences from DNA polymerase:

• It does not need a primer to start. It can begin building the RNA chain from scratch.
• It uses DNA as a template but builds an RNA strand (which uses uracil instead of thymine).
• It is less accurate than DNA polymerase — it has no proofreading ability. This is acceptable because RNA molecules are temporary and get replaced. …