Chapter 18 & 20 Flashcards
What is a Virus?
- Can only reproduce by invading other cells
A Non living particle made up of proteins and nucleic acids.
How are viruses classified?
According to their genetic and physical properties, -also by the type of host it infects. NOT into domains
4 shapes of viruses
Polyhedral, Spherical, Helical, Complex
What is the main Difference between Lytic and Lysogenic Infections?
With Lytic Infections, the DNA of the Virus enters the cell and makes
thousands of copies of the virus immediately. With Lysogenic Infections, The host cell is not immediately taken over, The viral nucleic acid is inserted into the host cell’s DNA
Prophase
Bacteriophage DNA that becomes embedded in the bacterial host’s DNA
About 70% of viruses contain RNA rather than DNA.
In humans, RNA can cause a wide range of infections from Mild colds, to AIDS, to Cancer.
HIV is a retrovirus, meaning…
The genetic information of a retrovirus is copied from RNA to DNA instead of from DNA to RNA
6 Kingodms
- Eubacteria 2. Archaebacteria 3. Protista 4. Fungi 5. Plantae 6. Animilia
3 domains
Bacteria (Eubacteria)
Archae (Archaebacteria)
Eukarya (Everything else)
Domain bacteria - most abundant - yes cause disease
Unicellular, prokaryote, thick, walls YES CONTAIN PEPTIDOGLYCAN
Domain Archaea - does not cause disease
Unicellular, Prokaryote, lives in extreme environment, NO PEPTIDOGLYCAN in cell membranes
Domain Eukarya - basically everything
All organisms that have a nucleus, protists, fungi, plantea, animilia
3 Prokaryote shapes
Bacilli: rod shaped
Cocci: Spherical
Spiral: spirilla
Ex. Strepto-coccus is spherical
Energy Capture by Prokaryotes - 4 Modes of Nutrition:
Heterotroph - “other feeder”
Photoheterotroph - “light and other feeder”
Photoautotroph - “Light self-feeder”
Chemoautotroph - “chemical self-feeder”
Binary fission
When a prokaryote has grown so that it has nearly doubled in size it replicated to DNA and divides in half producing 2 identical cells
