Bacteria & Viruses Biology Objective 4.03 Assess, describe, & explain adaptations affecting survival & reproductive success in disease-causing viruses & microorganisms. Biology
2 Bacteria Kingdoms Archaebacteria Eubacteria Harsh environment High temperatures High salinity Acidic Eubacteria Everywhere else
General Structure of Bacteria Prokaryotic No nucleus or membrane bound organelles Lots of ribosomes Thick cell wall Circular chromosomes (DNA) Reproduce by binary fission Asexual reproduction Makes an exact copy
Binary Fission
Bacteria…Good, Bad or Both? Bacteria is good! food (yogurt) medicines (insulin) recycles nutrients decompose nitrogen fixation Bacteria is bad! Decay/rot food Rot teeth Cause disease/ infections (strep throat) Antibiotics are used to clear up bacterial infections.
Viruses Considered to be nonliving because it cannot reproduce on its own General Structure Protein coat on the outside Nucleic acid on the inside (DNA or RNA)
Examples of Viruses Influenza- the flu HIV- AIDS Varicella- chicken pox & shingles Polio virus- polio Rubella or measles- measles Rhinovirus- cold
Reproductive Cycles Lytic Cycle Virus DNA enters the host cell Hijacks host to make DNA and protein Puts virus together Cell bursts and releases virus Virus is active: OUTBREAK!
Reproductive Cycles Lysogenic Cycle Very similar to lytic cycle Virus DNA is integrated into host cell Cell eventually ruptures with new virus after several generations Virus is dormant: HIDDEN!
Our Immune System Responsible for protecting the body from disease
Lines of Defense 1st line: skin 2nd line: cells release chemicals Acts as a barrier 2nd line: cells release chemicals blood flow to invaded region increases white blood cells attack the invaders. 3rd line: Involves attacking pathogens macrophages B cells T cells
Types of Immunity Active Immunity Exposed to disease Develop disease and become immune Longer lasting Passive Immunity Injected with antibody that another organism made Not permanent Vaccinations are given to induce artificial immunity