Viruses may have arisen from mobile genetic elements that gained the ability to move between cells. They may be descendants of previously free-living organisms that adapted a parasitic replication strategy. Perhaps viruses existed before, and led to the evolution of, cellular life.
Q. What are the three main roles of DNA?
Three roles of the DNA molecule in heritage are in storage, copying and transmitting genes. Every cell contains DNA, where is the complete genetic material stored.
Table of Contents
- Q. What are the three main roles of DNA?
- Q. What is DNA virus and RNA virus?
- Q. What tiny particle gets inside a cell and often destroys the cell?
- Q. Do viruses trick cells?
- Q. How can a virus get into a cell?
- Q. What is the main human defense against viruses?
- Q. What two things does every virus have?
- Q. What is smaller than a germ?
Q. What is DNA virus and RNA virus?
DNA viruses contain usually double‐stranded DNA (dsDNA) and rarely single‐stranded DNA (ssDNA). These viruses replicate using DNA‐dependent DNA polymerase. Compared to DNA virus genomes, which can encode up to hundreds of viral proteins, RNA viruses have smaller genomes that usually encode only a few proteins.
Q. What tiny particle gets inside a cell and often destroys the cell?
virus
Q. Do viruses trick cells?
Viruses can’t make new viruses on their own. Instead, they take over cells, and trick the cell into making new viruses. To enter the cell, a virus floats up to, or lands on a cell, then attaches to a receptor. Receptors are proteins on the surface of cells that act like locks.
Q. How can a virus get into a cell?
Virus entry into animal cells is initiated by attachment to receptors and is followed by important conformational changes of viral proteins, penetration through (non-enveloped viruses) or fusion with (enveloped viruses) cellular membranes. The process ends with transfer of viral genomes inside host cells.
Q. What is the main human defense against viruses?
The major defense against virus-infected cells is the CD8+ T-cell, also called cytotoxic T cell (CTL), killing of virus-infected cells. In immunology, all proteins are called “CD” followed a number, because immunologists have no imagination, and they never got on board with the whole “mp3” phenomenon.
Q. What two things does every virus have?
All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid. Some viruses are also enclosed by an envelope of fat and protein molecules. In its infective form, outside the cell, a virus particle is called a virion.
Q. What is smaller than a germ?
Viruses are even smaller than bacteria. They aren’t even a full cell. They are simply genetic material (DNA or RNA) packaged inside of a protein coating. They need to use another cell’s structures to reproduce.
