Mention the role of DNA and RNA in living organisms?

http://www.dummies.com/how-to/content/what-is-the-role-of-nucleic-acids-in-living-things.html

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are essential molecules in living organisms, playing crucial roles in genetic information storage, expression, and protein synthesis.

1. DNA: DNA serves as the primary genetic material in most living organisms. It is structured as a double helix, consisting of two complimentary strands held together by hydrogen bonds. The roles of DNA are as follows:
- Genetic information storage: DNA carries the instructions needed to develop, function, and reproduce an organism. It contains genes, which are specific segments that code for proteins and control various traits.
- Replication: DNA is capable of replicating itself during cell division. This ensures that each newly formed cell receives an identical copy of the genetic information.
- Transcription: DNA provides the template for the synthesis of RNA molecules through a process called transcription.

2. RNA: RNA plays several roles in gene expression and protein synthesis. There are different types of RNA, each performing distinct functions:
- mRNA (messenger RNA): It carries the genetic information from the DNA, serving as a template for protein synthesis during a process called translation.
- rRNA (ribosomal RNA): It is a component of ribosomes, the cellular structures responsible for protein synthesis. It assists in the assembly and catalytic activity of ribosomes.
- tRNA (transfer RNA): It delivers specific amino acids to the ribosome during translation, matching them with the codons on the mRNA molecule.
- Other regulatory RNAs: These include microRNAs (miRNAs) and small interfering RNAs (siRNAs) that control gene expression by binding to mRNA molecules and regulating their stability or translation.

Understanding the roles of DNA and RNA in living organisms requires knowledge of molecular biology, cell biology, and genetics. Further exploration of these disciplines can provide a detailed understanding of how DNA and RNA contribute to the functioning of living organisms.