Nucleic acid core surrounded by protein coat (capsid); contains DNA and RNA
Why is a virus not considered a living organism?
Lack of nucleus and membrane- bound oragnisms, requires no nutrients and is completely dependent on another organisms for survival. They can only reproduce with the help of a cell
What is a bacteriophage?
Looks like a robot; viruses that only infect bacteria cells. Protein coat on outside and genetic info on inside
What is tobbacco mosaic virus
Virus that affected tobbacco plants in the 30s and the first virus we ever identified. Wendell Stanley
Why is HIV considered a retrovirus.
becuase HIV contains RNA as its nucleic acid
What is vaccinne? how does it work?
Substances that contain parts of anitgens from an infectious organism. By stimulating an immune response, they protect the body against subsequent infection of that organism, its like a killed version of the virus
when did bacteria appear on earth?
3.5 billion years ago
What are 3 shpaes of bacteria?
Bacilli- rod shaped, Coccus- round, Spirochetes- spiral
What are some differences between Archae and other bacteria?
Archeae lives in more extereme enviornments where there is not a lot of oxygen
Archeae live in extreme conditions. give examples
Thermopheils- very hot condidtions, halophiles- very salty, Methagens- not oxygen
difference between gram postiive and gram negative?
Gram positie holds the purple howver the negatative's purple cmes right off