DNA formed from RNA is

Options

A. ADNA
B. BDNA
C. cDNA
D. ZDNA

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks for the type of DNA that is formed from RNA. This indicates a process where RNA serves as a template to synthesize DNA.

2. **Identifying the Process**: The process of synthesizing DNA from RNA is known as reverse transcription. This is the opposite of transcription, where DNA is used to synthesize RNA.

3. **Key Enzyme Involved**: The enzyme responsible for catalyzing the synthesis of DNA from an RNA template is called reverse transcriptase. This enzyme plays a crucial role in the formation of DNA from RNA.

4. **Defining cDNA**: The DNA synthesized from an RNA template is known as complementary DNA (cDNA). This term is essential in molecular biology, especially in cloning and gene expression studies.

5. **Differentiating DNA Types**: While there are various forms of DNA, such as A-DNA, B-DNA, and Z-DNA, these forms are not directly related to the process of forming DNA from RNA. They refer to the structural variations of DNA.

6. **Conclusion**: Therefore, the correct answer to the question is cDNA, as it specifically refers to the DNA that is synthesized from an RNA template.

**Final Answer**: cDNA (complementary DNA)

---