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“Simple” Organisms Is a virus a living thing? Viruses, although not technically living due to the lack of cellular structure, are classified as microorganisms. Viruses- Not living Living Cell Virus Asexual or Reproduction- only with a sexual host cell Genetic code- DNA or RNA DNA Growth/ development- NO Yes Obtain and use energy- NO Yes Response to environment Yes NO Change overtime- Yes Virus- Latin= “poison” Have nucleic acids, protein, and come have lipids But they ARE NOT living Core = RNA or DNA that is surrounded by protein coat Will bind to a receptor on the host and infect their DNA into the host Is a virus a living thing? Viruses are composed of a protein coat (called a capsid) that protects a nucleic acid - either DNA or RNA. The shape of the capsid determines the type of cell the virus can infect. Is a virus a living thing? A virus can only exist by infecting a host cell. Viruses are classified by the reproductive cycle it uses to infect the host cell. Virus Fill It In … Name 2 reasons that viruses are not considered living things: 1. 2. Is a virus a living thing? 1. The lytic cycle describes the “life cycle” in which a virus uses the host cell to make copies of itself, then quickly kills the host cell as new virus copies are released. https://www.youtube.com/watch ?v=3DP-MAhr0YY Lytic Cycle Make copies of itself and infect host cell Cell cannot tell the difference between virus’ DNA and its own Will transcribe and translate viral DNA Viral DNA and protein will eventually chop and KILL the host cell Is a virus a living thing? 2. The lysogenic cycle describes the “life cycle” in which the virus has a dormant stage in which the virus remains inactive within the cell. This dormant period may last for weeks, months, or years. An environmental trigger may cause the viral DNA to emerge from the host DNA and begin a lytic cycle of reproduction. Lysogenic Will integrate itself into the host DNA Will remain dormant for some time It will eventually replicate itself along with the host DNA Fill It In … Using the diagram, explain how lytic and lysogenic are different: How a virus works Is a virus a living thing? Viruses are pathogenic, or disease-causing microorganisms Is a virus a living thing? HIV causes AIDS. HIV infects T-cells, which are important for the immune response. Thus, people with AIDS often die of opportunistic infections, such as pneumonia. Is a virus a living thing? Several different viruses cause influenza (the “flu”). The influenza viruses mutate rapidly, meaning the actual virus being spread changes with each outbreak. Is a virus a living thing? Flu epidemics are caused by viruses that are genetically different enough from earlier years’ viruses that people have little immunity to them. Is a virus a living thing? Influenza viruses infect respiratory cells. The lysis of these cells leads to some of the typical symptoms of the flu, such as sore throat and congestion. Is a virus a living thing? A poxvirus causes smallpox. Special efforts have eradicated the smallpox disease; however samples of the smallpox virus were kept for study and are currently stored at the CDC in Atlanta. Is a virus a living thing? Smallpox starts in the cells of the lymph nodes and lungs, then moves into other internal organs and the skin. Symptoms include severe headaches, muscle ache, and pustules on the skin. Virus Prevention and Treatment Vaccines can be developed for viral diseases. A vaccine uses a dead or weakened form of the virus to “turn on” the immune response so that antibodies are produced. Virus Prevention and Treatment Vaccines can be developed for viral diseases. A vaccine uses a dead or weakened form of the virus to “turn on” the immune response so that antibodies are produced. Virus Prevention and Treatment Active immunity to a virus is conferred by a vaccine or by exposure to the virus itself. Passive immunity is conferred when antibodies are passed between individuals (ie. through breast milk). Antiviral medications work by interrupting the virus’s life cycle. Antibiotics are NOT effective against viruses! Vaccines Resembles disease causing agent Made from weakened or dead microbe Stimulates immune system and creates memory cells Active immunity Production of antibodies by an organism after an encounter Natural- Due to infection Artificial- Vaccination Passive Immunity Acquisition if antibodies from another organism Natural- pass from mother to child during placenta or breast milk Artificial- Immune serum or antivenom Viruses and Natural Selection Viruses often mutate rapidly, meaning the actual virus being spread changes with each outbreak. Viruses and Natural Selection 2.Mutations in the HIV virus make developing a treatment or vaccine difficult. Viruses that are resistant due to mutations can survive and reproduce by natural selection. 3.Flu epidemics are caused by viruses that are genetically different enough from earlier years’ viruses that people have little immunity to them. Fill It In … Identify 3 viral diseases: 1. 2. 3. Check Yourself! 1. What are the two parts of a virus? 2. What are the two reproductive cycles of viruses? 3. What is a pathogen? 4. What type of cell does HIV infect? 5. Why is there a different flu virus each year? Check Yourself! 1. What are the two parts of a virus? CAPSID (PROTEIN COAT) NUCLEIC ACID (DNA OR RNA) Check Yourself! 2. What are the two reproductive cycles of viruses? LYTIC CYCLE & LYSOGENIC CYCLE Check Yourself! 3. What is a pathogen? DISEASE-CAUSING MICROORGANISM Check Yourself! 4. What type of cell does HIV infect? T-CELLS Check Yourself! 5. Why is there a different flu virus each year? IT RAPIDLY MUTATES Are all bacteria “bad”? All bacteria are classified in the kingdoms Eubacteria and Archeabacteria. They are differentiated by the chemicals found in the bacterial cell wall. They are all unicellular and prokaryotic. Bacteria Eubacteria Archaebacteria Eubacteria Largest Kingdom Live Everywhere Have cell wall made of peptidoglycan Some have second membrane Spores Look similar and lack nuclei Have cell wall but NO peptidoglygan and have a different lipid DNA show relation to eukaryotes Live in VERY harsh environments HOT, Salty, No Oxygen Cell wall Gram staining Gram Positivehas peptidoglycan cell wall Will turn violet Gram Negativeno peptioglycan cell wall Will be a lighter color (pink) Are all bacteria “bad”? Bacteria typically reproduce through binary fission, but can also exchange DNA in a process known as conjugation. This allows for genetic variation in a bacterial population. Are all bacteria “bad”? The vast majority of bacteria in our world are beneficial. They are important decomposers and perform many other ecosystem services. They exist in the intestines of some animals and aid digestion. They are also important in food production. Are all bacteria “bad”? Some bacteria are pathogenic. One example is the bacterium Mycobacterium tuberculosis, which causes tuberculosis. The disease attacks the lungs and causes coughing, chest pain, fatigue and fever – it can be fatal if not treated. This bacterium causes disease because it destroys cells. The cells are broken down by the bacteria as a source of nutrition. Other bacteria harm the host by releasing toxins such the bacterium that causes food poisoning. Are all bacteria “bad”? D. Pathogenic bacteria can be treated with antibiotics. Antibiotics kill the bacteria by destroying the cell wall. Bacteria that are resistant to antibiotics can survive and reproduce by natural selection. This means that new antibiotics must continually be developed. Bacteria Fill It In … Identify 3 ways that bacteria are beneficial: 1. 2. 3. Importance to Humans Decomposers- will break down dead organisms Clean sewage Eat dead tissue Nitrogen fixation Will take N2gas and make NH3 a compound plants and animals can use Human useIn stomach- help make vitamins (biotin and Vit K) Are all bacteria “bad”? Some bacteria are pathogenic (cause disease). One example is the bacterium Mycobacterium tuberculosis, which causes tuberculosis or TB. Are all bacteria “bad”? The disease usually attacks the lungs and causes coughing, chest pain, fatigue and fever it can be fatal if not treated. This bacterium causes disease because it destroys cells. The cells are broken down by the bacteria as a source of food/nutrition. Are all bacteria “bad”? Other bacteria harm the host by releasing toxins such as the bacterium that causes food poisoning. Check Yourself! 1. Which two kingdoms include bacteria? 2. How do bacteria reproduce? 3. Name two ways that bacteria cause illness. Check Yourself! 1. Which two kingdoms include bacteria? EUBACTERIA & ARCHEABACTERIA 2. How do bacteria reproduce? 3. Name two ways that bacteria cause illness. Check Yourself! 1. Which two kingdoms include bacteria? EUBACTERIA & ARCHEABACTERIA 2. How do bacteria reproduce? BINARY FISSION & CONJUGATION 3. Name two ways that bacteria cause illness. Check Yourself! 1. Which two kingdoms include bacteria? EUBACTERIA & ARCHEABACTERIA 2. How do bacteria reproduce? BINARY FISSION & CONJUGATION 3. Name two ways that bacteria cause illness. -DESTROY CELLS FOR FOOD -RELEASE TOXINS What is a protist? Protista is a diverse kingdom of organisms that is divided into 3 main groups: Algae (plant-like) Protozoa (animallike) Slime molds (fungus-like) What is a protist? Algae are important aquatic producers (the base of aquatic food webs) and produce most of earth’s oxygen. They may be unicellular or multicellular. What is a protist? Protozoa are unicellular, aquatic protists that are similar to animals. Protozoa have adaptations that allow them to accomplish life functions: What is a protist? Adaptations for movement include a whiplike tail called a flagellum, tiny hairlike projections called cilia, or extensions of the cell membrane called pseudopodia. What is a protist? An adaptation for water balance is the contractile vacuole. This vacuole pumps excess water out of the cell, since these aquatic organisms may take in more water than necessary by osmosis. What is a protist? An adaptation for response to stimuli is the eyespot. This structure allows or responses to light (movement toward or away). Fill It In … Draw a simple diagram of a paramecium. Label the cilia, contractile vacuole, and eyespot. What is a protist? In protozoa, reproduction is asexual through binary fission. Some protists may exchange DNA through conjugation. What is a protist? Some protists are pathogenic. Malaria is a disease caused by parasitic protists called plasmodia. Malaria is transmitted by a mosquito. Any organism which transmits/carries a disease without being affected by the disease is called a vector. Malaria in human Malaria in a mosquito What is a protist? The symptoms of malaria include headache, shaking, chills, and fever. Some forms of malaria lead to comas, convulsions, or even death. http://www.youtu be.com/watch?v =a4aZE5FQ284 Transport: moves using CILIA (tiny hair like projections). CILIA can also help them grab food. Excretion: uses its contractile vacuoles to excrete water/waste. Respiration: uses diffusion to get oxygen (aerobic) Nutrition: Heterotrophic (eats bacteria, algae) Engulfs food using its cilia which enter through the oral groove. The food is packed into a vacuole and enzymes break it down. Waste leaves via anal pore. Reproduction: Sexual via conjugation OR Asexual using budding Growth and development: none really they can “grow” by uptaking excess water/food CAN USE CHEMOTAXIS/PHOTOTAXIS TO ORIENT IN THEIR ENVIRONMENT I. Paramecium http://www.youtube.com/watch? v=fI7nEWUjk3A III. Euglena Transport: moves using a FLAGELLA. Excretion: uses its contractile vacuole Respiration: uses diffusion to get oxygen (aerobic) Nutrition: Mainly photosynthetic (BECAUSE IT HAS EATEN ALGAE) using chloroplast but can engulf food, if needed Reproduction: Asexual using Mitosis Growth and development: none really they can “grow” by uptaking excess water/food CAN USE PHOTOTAXIS TO ORIENT IN THEIR ENVIRONMENT II. Amoeba http://www.youtube.com/watch? v=7pR7TNzJ_pA Transport: moves using PSEUDOPODS which can also help them grab food. Excretion: uses its contractile vacuoles to excrete water/waste. Respiration: uses diffusion to get oxygen (aerobic) Nutrition: Heterotrophic Engulfs food using its pseudopods which break fold inward to create a vacuole. Enzymes break it down. Waste leaves via diffusion. Reproduction: Asexual using mitosis Growth and development: none really; they can “grow” by uptaking excess water/food CAN USE CHEMOTAXIS/PHOTOTAXIS TO ORIENT IN THEIR ENVIRONMENT Check Yourself! 1. What are the 3 groups of protists? 2. Name 2 reasons that algae are important. 3. What protist causes the disease malaria? Check Yourself! 1. What are the 3 groups of protists? ALGAE (PLANT-LIKE) PROTOZOA (ANIMAL-LIKE) SLIME MOLD (FUNGUS-LIKE) 2. Name 2 reasons that algae are important. 3. What protist causes the disease malaria? Check Yourself! 1. What are the 3 groups of protists? ALGAE (PLANT-LIKE) PROTOZOA (ANIMAL-LIKE) SLIME MOLD (FUNGUS-LIKE) 2. Name 2 reasons that algae are important. BASE OF AQUATIC FOOD WEBS & PRODUCE MOST OF EARTH’S OXYGEN 3. What protist causes the disease malaria? Check Yourself! 1. What are the 3 groups of protists? ALGAE (PLANT-LIKE) PROTOZOA (ANIMAL-LIKE) SLIME MOLD (FUNGUS-LIKE) 2. Name 2 reasons that algae are important. BASE OF AQUATIC FOOD WEBS & PRODUCE MOST OF EARTH’S OXYGEN 3. What protist causes the disease malaria? PLASMODIA How are fungi different from plants? Fungi are eukaryotic organisms that may be unicellular or multicellular. How are fungi different from plants? Fungi are heterotrophic. They obtain food through extracellular digestion, secreting digestive chemicals and absorbing nutrients across the cell wall. How are fungi different from plants? Fungi may reproduce asexually, such as budding in yeast or spore production in mushrooms. Spores can also be used in sexual reproduction. Fill It In … List 2 ways that fungi can reproduce: 1. 2. How are fungi different from plants? Some fungi are pathogenic. Candida is a yeast (fungus) that is one of the normal inhabitants of moist human epithelial tissue, such as the throat and vagina. How are fungi different from plants? Certain circumstances (such as change in pH or sudden decrease in helpful bacteria) can cause Candida to become pathogenic by growing too rapidly and releasing harmful substances. The condition caused by this growth is called candidiasis. Candidiasis leads to oral thrush, yeast infections, and/or kidney infections. Check Yourself! 1. How do fungi obtain food? 2. What reproductive structure can be used for sexual or asexual reproduction? 3. What is the name of the fungus that causes thrush? Check Yourself! 1. How do fungi obtain food? EXTRACELLULAR DIGESTION 2. What reproductive structure can be used for sexual or asexual reproduction? 3. What is the name of the fungus that causes thrush? Check Yourself! 1. How do fungi obtain food? EXTRACELLULAR DIGESTION 2. What reproductive structure can be used for sexual or asexual reproduction? SPORES 3. What is the name of the fungus that causes thrush? Check Yourself! 1. How do fungi obtain food? EXTRACELLULAR DIGESTION 2. What reproductive structure can be used for sexual or asexual reproduction? SPORES 3. What is the name of the fungus that causes thrush? CANDIDA