Chapter Summary

     Viruses' do not all look the same. Their structure always includes a capsid but the capsid can be different shapes and the complexity of the capsid. A viral envelope sometimes may be present around the capsid. Viral replication has 6 steps; attachment (virus attaching to host cell), entry (genome enters host cell, sone virus genes expressed immediately), integration (viral genes intergrate into host cell chromosomes) , synthesis of viral components ( new virus made by the host cell), viral assembly(all parts of virus made then assembled), and release (new virus released from the host cell

AIDS cause by human immunodeficiency virus.  Destruction of helper T cells by the invasion of an HIV. With helper T cells being destroyed the body becomes susceptible to diseases. It is hard to make a drug to kill the HIV because HIV does not contain a reverse transcriptase causing mutations to occur in the virus. 

The lytic cycle produces new phages and destrying the bacterial cells. While, the lysogenic cycle the viral genome is integrated into chromosomes and replication of cell involuntarily produces more cells. The lysogenic stage can be influenced by environmental conditions.

Bacterial chromsomes are double stranded, circular, and shorter than eukaryotic DNA. Plasmids are small circular pieces of DNA no part of the bacterial chromosome. Plasmids carry genes that can aid in survival.

Gene transfer can be done through 3 mechanism; conjugation, transformation, and transduction. Resistance against antibiotics occurs because one resistant gene may be transferred to many bacteriums.  

Useful Materials

1. How do Viruses Work? (03/14/11) - The title says it all. A professor discusses viruses and demonstrates how manipulative viruses are.  
2. Bacterial Conjugation Video (03/14/11) - A brief video of this form of gene transfer. If having trouble remembering this video just shows what happens in a simplistic way. 

1. H5N1, China (03/14/11) - The title grabbed my attention because it was similar to the H1N1 flu. They must be in the same family of virus. The article discusses a flu infecting birds and how this same flu and been seen in many other countries. The author speculates that the birds play a role in a global virus dissemination because they are migrating and taking the flu to many different