In biochemical processes, cDNA is prepared from

Options

A. B-DNA
B. hnRNA
C. Z-DNA
D. mRNA

Answer

**Step-by-Step Solution:**

1. **Understanding cDNA**: cDNA stands for complementary DNA. It is synthesized from a single-stranded RNA template, specifically messenger RNA (mRNA).

2. **Source of cDNA**: The process of creating cDNA involves the enzyme reverse transcriptase, which catalyzes the synthesis of cDNA from mRNA. Therefore, cDNA is a DNA copy of the mRNA molecule.

3. **Identifying the Correct Option**: Among the given options (bDNA, hnRNA, zDNA, and mRNA), we need to identify which one is the source for cDNA.
- **bDNA** and **zDNA** are forms of double helical DNA and are not involved in the synthesis of cDNA.
- **hnRNA** (heterogeneous nuclear RNA) is the precursor to mRNA but is not directly used to synthesize cDNA.
- **mRNA** (messenger RNA) is the correct answer because it is the direct template from which cDNA is synthesized.

4. **Conclusion**: The correct answer to the question "In biochemical processes, cDNA is prepared from" is **mRNA**.

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