<p> Name : ______Date : ______</p><p>VIRUSES : Viral Structure and Life Cycles : Notes #1</p><p>A) Structure of a Virus</p><p>-Composed of a core of ______</p><p> surrounded by a ______</p><p>______</p><p>-The Capsid ______the nucleic acid core.</p><p>-Nucleic Acid can be ______but never both. (retroviruses contain RNA)</p><p>-The ______helps attach the virus to the cell</p><p>-The ______the nucleic acid into the cell.</p><p>- The picture shown above is that of a ______</p><p>______</p><p>- There are three main shapes of Viruses. See pictures below:</p><p>______</p><p>B) Biotic( ______) or ______(______) **Viruses straddle the fence between living and non-living ALIVE Non-Living - Have DNA or RNA and ______- Acellular – not made of cells (No non-living thing contains ______/protein) - ______- Can ______- ______- Have ______- Do not move - Can reproduce** *** Do ______- Demonstrate some level of being able ______to ______</p><p>** Some biologists describe viruses as being non-living infectious particles</p><p>C) Viral Life Cycles - Two main types of Life Cycles (Viral Replication) for viruses: 1) -______2) -______</p><p>1) LYTIC CYCLE OF A VIRUS: - In the Lytic Life Cycle (shown below),______</p><p>______</p><p>______.</p><p>______This process takes place very quickly.</p><p>- Viruses that reproduce through a lytic cycle are ______</p><p>- ______: A virus that makes many copies of itself in its host cell; ______and release the reproduced viruses to spread to many more host cells. </p><p>- This process only takes about ______from beginning to end.</p><p>2) LYSOGENIC CYCLE OF A VIRUS</p><p>- Another way in which some viruses affect a cell is through a ______</p><p>______. The virus does not reproduce and lyse of the host cell (as was the case in the lytic cycle) – at least not right away.</p><p>-______</p><p>______</p><p>______</p><p>- Like the Lytic Cycle, the DNA of the virus is injected into the host cell. </p><p>- Once integrated into the Host cell’s DNA, the viral DNA is known as </p><p>______</p><p>- The PROPHAGE may remain combined as part of the DNA of the host cell for many generations. ______. - As long as this prophage (viral DNA) does not cause lysis it is considered to be - acting as a ______, sometimes a temperate phage will get triggered (______) to enter into the</p><p>Lytic Cycle. This temperate phage now becomes a ______</p><p>______</p>