BACTERIA & VIRUSES

Biology

Objective 4.03Assess, describe, & explain adaptations

affecting survival & reproductive success in disease-causing viruses & microorganisms.

2 Bacteria Kingdoms

Archaebacteria

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 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