DNA is a molecule of heredity because

Options

A. it is present in the nucleus
B. it gives rise to RNA
C. it can replicate
D. it is not killed by heat

Answer

**Step-by-Step Solution:**

1. **Understanding DNA**: DNA, or deoxyribonucleic acid, is the molecule that carries genetic information in living organisms. It is the main component of chromosomes and genes.

2. **Role in Heredity**: DNA is referred to as the molecule of heredity because it is responsible for passing genetic information from parents to offspring. This transmission of traits is essential for the continuity of species.

3. **Replication of DNA**: One of the key features of DNA that makes it a hereditary material is its ability to replicate. Replication is the process by which DNA makes a copy of itself, ensuring that when cells divide, each new cell has the same genetic information.

4. **Meiosis and Variation**: During sexual reproduction, DNA undergoes a process called meiosis, which leads to the formation of gametes (sperm and egg cells). This process introduces genetic variation, which is crucial for evolution and biodiversity.

5. **Evaluating Options**:
- **Present in the nucleus**: While DNA is found in the nucleus, it is also present in mitochondria and chloroplasts, and this does not solely define its role in heredity.
- **Gives rise to RNA**: While DNA does give rise to RNA through transcription, this process is related to protein synthesis and not directly to heredity.
- **Can replicate**: This is the correct answer, as replication is essential for the transmission of genetic information.
- **Not killed by heat**: DNA can be damaged by heat, which makes this option incorrect.

6. **Conclusion**: Therefore, the correct answer to the question is that DNA is a molecule of heredity because it can replicate, allowing it to pass genetic information from one generation to the next.

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