Facts for Prelims
Source: TH
Context: The article explains why most deadly viruses contain RNA, unlike most organisms which use DNA to store genetic information
What is an RNA?
| Property | RNA | DNA (Deoxyribonucleic acid) |
| Structure | Single-stranded
|
Double-stranded
|
| Sugar component | Ribose | Deoxyribose |
| Bases | Adenine, guanine, cytosine, uracil | Adenine, guanine, cytosine, thymine |
| Function | · mRNA carries genetic information from DNA to the ribosomes for protein synthesis
· Transfer RNA (tRNA) delivers amino acids to the ribosomes · Ribosomal RNA (rRNA) helps to catalyse protein synthesis |
Genetic material carries genetic information |
| Stability | Less stable | More stable |
| Mutation rate | Higher mutation rate | Lower mutation rate |
| Replication | Not self-replicating, need a DNA template | Self-replicating |
| Genetic information | Can act as genetic material in some viruses | The primary genetic material in organisms |
Why do most deadly viruses contain RNA?
| Reasons | Explanation | Examples |
| High mutation rate | RNA viruses change quickly, allowing them to adapt to new environments and host species | Influenza virus, HIV, SARS-CoV-2 |
| Recombination | RNA viruses can exchange genetic material, leading to the emergence of new strains | Norovirus, Hepatitis C virus, Rotavirus |
| Wide host range | RNA viruses can infect a variety of hosts, including animals and humans, leading to zoonotic diseases | Ebola virus, Zika virus, Nipah virus |
| High viral loads | RNA viruses can replicate quickly, producing large amounts of virus that can overwhelm the host’s immune system | Hepatitis A virus, Dengue virus, yellow fever virus |
On the other hand, DNA is more stable, error-free and doesn’t mutate easily.
