3 Generally smaller than 200 nm in diameter. The VirusesViruses are noncellular and thus cannot be classified with cellular organisms.Generally smaller than 200 nm in diameter.Each type has at least two parts.Capsid: Outer layer composed of protein subunits.Nucleic acid core: DNA or RNA.Mader: Biology 8th Ed.
5 Classification is based on: Type of nucleic acid. Size and shape. The VirusesClassification is based on:Type of nucleic acid.Size and shape.Presence / absence of outer envelope.Mader: Biology 8th Ed.
7 Can infect a wide variety of cells, but are very specific. Parasitic NatureViruses are obligate inrtracellular parasites (cannot reproduce outside a living cell).Can infect a wide variety of cells, but are very specific.Bacteriophages - Infect bacterial cells.Mader: Biology 8th Ed.
8 Virus takes over metabolic machinery of the host cell. Viral ReproductionViruses gain entry into host because portions of capsid adhere to a specific receptor on the host cell’s outer surface.Viral nucleic acid enters the cell and once inside, the nucleic acid codes for the protein units inside the capsid.Virus takes over metabolic machinery of the host cell.Mader: Biology 8th Ed.
9 Lytic cycle may be divided into five stages: Attachment Penetration BiosynthesisMaturationReleaseMader: Biology 8th Ed.
10 Phage becomes a prophage that is integrated into the host genome. Lysogenic CyclePhage becomes a prophage that is integrated into the host genome.Becomes latent, and later may reenter the lytic cycle.Mader: Biology 8th Ed.
11 Reproduction of Animal Viruses After animal viruses enter the host cell, uncoating releases viral DNA or RNA and reproduction occurs.If viral release occurs by budding, the viral particle acquires a membranous envelope.RetrovirusesContain reverse transcriptase which carries out RNA cDNA transcription.Mader: Biology 8th Ed.
13 Viral InfectionsViruses are best known for causing infectious diseases in plants and animals.Herpes, HIV, cancerViruses lack enzymes; thus, antibiotics have no effect.Many crop diseases have been attributed to viroids (naked strands of RNA).Some human and other animal diseases have been attributed to prions (protein molecules).Mad cow diseaseMader: Biology 8th Ed.
14 A single spoonful of earth can contain 1010 prokaryotes. The ProkaryotesThe prokaryotes include bacteria and archaea, which are fully functioning cells.A single spoonful of earth can contain 1010 prokaryotes.Range in size from 1-10µm in length and µm in width.Mader: Biology 8th Ed.
15 Lack a eukaryotic nucleus. Prokaryote StructureLack a eukaryotic nucleus.Have outer cell wall containing peptidoglycan.Some move by means of flagella.Lack membranous organelles.Contain nucleoid.May have accessory ring of DNA (plasmid).Mader: Biology 8th Ed.
17 Reproduction in Prokaryotes Prokaryotes reproduce asexually by means of binary fission.Conjugation occurs between bacteria when the donor cell passes DNA to recipient cell by way of sex pilus.Mader: Biology 8th Ed.
19 Reproduction in Prokaryotes Transformation occurs when bacterium picks up free pieces of DNA from other prokaryotes.Transduction occurs when bacteriophages carry portions of bacterial DNA from one cell to another.When faced with unfavorable conditions, some bacteria form endospores.Mader: Biology 8th Ed.
20 Prokaryotic Nutrition Obligate anaerobes are unable to grow in the presence of free oxygen.Facultative anaerobes are able to grow in either the presence or absence of gaseous oxygen.Mader: Biology 8th Ed.
21 Autotrophic Prokaryotes Photoautotrophs use solar energy to reduce carbon dioxide to organic compounds.PhotosyntheticChemoautotrophs oxidize inorganic compounds to obtain the necessary energy to reduce O2 to an organic compound.ChemosyntheticMader: Biology 8th Ed.
22 Heterotrophic Prokaryotes Most prokaryotes are chemotrophs that take in organic nutrients.Aerobic saprotrophs decompose most large organic molecules to smaller molecules.May be free-living or symbiotic.Nitrogen fixationCommensalismMader: Biology 8th Ed.
23 Gram-positive bacteria retain dye and appear purple. The BacteriaGroups of bacteria are commonly differentiated from one another using the Gram stain procedure.Gram-positive bacteria retain dye and appear purple.Gram-negative bacteria do not retain dye and appear pink.Mader: Biology 8th Ed.
24 Bacteria can also be classified in terms of their three basic shapes. The BacteriaBacteria can also be classified in terms of their three basic shapes.Spiral (spirilli), Rod (bacilli), and Round (cocci).Mader: Biology 8th Ed.
25 Cyanobacteria are Gram-negative bacteria that photosynthesize. Believed to be responsible for introducing oxygen into the primitive atmosphere.Lack visible means of locomotion.Can live in extreme environments.In association with fungi, form lichens.Mader: Biology 8th Ed.
27 The ArchaeaArchaea were considered bacteria until Carl Woese discovered their rRNA has a different sequence of bases than rRNA of bacteria.Eukarya are believed to be more closely related to archaea than to bacteria.Mader: Biology 8th Ed.
28 Archaea Structure and Function Plasma membranes of archaea contain unusual lipids that allow them to function at high temperatures.Some are methanogenic.Most are chemoautotrophs.None are photosynthetic.Sometimes mutualistic or commensalistic, but none are parasitic.Mader: Biology 8th Ed.
29 Found in anaerobic environments. Types of ArchaeaMethanogensFound in anaerobic environments.Produce methane from hydrogen gas and carbon dioxide.HalophilesRequire high salt concentrations for growth.ThermoacidophilesReduce sulfides and survive best at temperatures above 80oC.Mader: Biology 8th Ed.