A virus is a pathogenic agent, a infections particle, consisting of a core of nucleic acid (DNA or RNA) enclosed in a protein shell. Viruses are, in general, much smaller than bacteria and have a much smaller genome. But their genetic material is of many varieties, unknown in cellular organisms. Some of these are discussed here. Bacteriophage φX174 which attacks [...]
The upcoming discussion will update you about the difference between Lysogenic and Lytic Phases of a Virus. Difference # Lysogenic Phase: 1. The viral genome or its complementary DNA gets integrated with the host DNA. It is called pro-phage or provirus. 2. The host DNA is not hydrolysed during lysogenic phase. 3. The pro-phage or provirus replicates only once along [...]
The following points highlight the two main types of reproductive cycle in virus. The types are: 1. Lytic Cycle 2. Lysogenic Cycle. Type # 1. Lytic Cycle (Fig. 2.5): It is the reproductive cycle of virulent phages, e.g., T4 bacteriophage. The phage attaches itself to the host cell (e.g., Escherichia coli) through its tail fibres. The fibres bend and bring [...]