Transcript Slide 1
(C) compare the structures and functions of viruses to cells and describe the role of viruses in causing diseases and conditions such as acquired immune deficiency syndrome, common colds, smallpox, influenza, and warts; and (D) identify and describe the role of bacteria in maintaining health such as in digestion and in causing diseases such as in streptococcus infections and diphtheria. Flu HIV Viruses are tiny particles of DNA or RNA that are coated with protein. Sometimes they contain an envelope made of membrane. They can’t reproduce on their own and they won’t survive long outside a living cell. Here’s why! Ebola Viruses attach to the host cell membrane. They inject their DNA (instruction for making more viruses) inside the cell. They use the cell’s machinery to reproduce, they rupture (burst) the host cell. Some viruses can hide their DNA or RNA inside the host cell for many years before they begin to kill cells! HIV virus attacks white blood cells called T-cells. It causes the disease AIDS Smallpox, Chickenpox, flu, and warts are also caused by viruses. Adenoviruses cause the common cold. They attack cells in your respiratory system. Soil Bacteria Bacteria are different from viruses. They cause disease by secreting (dumping out) toxins that poison cells. Strep throat (streptococcus), diptheria, and staph infections are some diseases caused by bacteria. Not all bacteria are harmful! Many are BENEFICIAL! They provide something we need. Soil bacteria called nitrogen fixers make nitrogen in the air into fertilizer in the nitrogen cycle. Decomposers break waste back down into organic material and carbon dioxide. Some mammals rely on symbiotic bacteria in their guts to help with digestion. We use some bacteria to produce food like yogurt and soy sauce. Type Virus Bacteria Plant cells Not a cell Prokaryotic cell- no nucleus Living Eukaryotic cell- nucleus Eukaryotic cell- nucleus Living Living Can’t live on its own Animal cells Structure Protein coat DNA or RNA envelope Cell wall, cell membrane, ribosomes, DNA loop NO nucleus Nucleus with DNA, cell wall, cell membrane, ribosomes, chloroplast Nucleus with DNA, cell membrane, Ribosomes No cell wall, No chloroplast Reproduction Host cell required Asexual; fission Mitosisgrowth/repair Meiosissexual reproduction Mitosisgrowth/repair Meiosissexual reproduction Picture (not to drawn to scale!)