Bacteria/Virus test
"Bacteria are unicellular, prokaryotic organisms," describe what this statement means.
This statement means that bacteria are single celled organisms, that have no nucleus.
"Viruses are specific," what does this statement mean?
This statement means that viruses have a specific host that they infect. A cactus virus will only infect one certain type of cactus. The virus will not infect any other organism. In rare matters, the virus will have 2 hosts that it infects.
How does a virus recognize the correct host or cell to infect?
Through the process of recognition, marker proteins identify the correct host to infect.
List 2 structures (organelles) found in a eukaryotic cell that are not present in a bacteria?
Two structures found in a eukaryotic cell that are not present in a bacteria are a nucleus and mitochondria.
What is a vaccine? In general, how do vaccines work? Explain why a vaccine has been made for measles but not HIV.
Vaccines are used as prevention against viruses. Vaccinations are only useful against viruses that do not evolve rapidly. Vaccines are meant to prevent viruses by putting a little of the virus inside of you so your immune system can fight it off. A vaccine has been made for measles but not HIV because unlike measles, HIV mutates rapidly and is hard to be identified.
Discuss in a few sentences why viruses are not classified as living organisms.
Viruses are not living organisms because they do not have the all of the 5 characteristics of life. They do not have cells because their particles cannot make proteins. They do not have metabolism because they are too simple to obtain/make energy; they only need it to reproduce and they steal it from the cells they infect. They do reproduce, but only inside the host. They also have heredity (DNA or RNA). Although they do not have homeostasis because they have no method for controlling their internal environment.
Define virus
A virus is a microscopic particle (microbe) that invades the cells of living organisms. All viruses are pathogens.
Explain the basic structure of all viruses.
All viruses are made up of two basic parts: core-nucleic acid (DNA or RNA) capsid- protein coat that surrounds core.
What is antibiotic resistance? What is the major contributing factor of antibiotic resistance by humans?
Antibiotic resistance refers to bacteria that are no longer killed by antibiotic treatment. Major contributing factors are people don't finish prescriptions, and overuse/misuse antibiotics
Contrast antiseptics and disinfectants in terms of their uses. Give an example of an antiseptic and a disinfectant.
Antiseptics-chemicals that kill bacteria on living tissue. Ex) Bactine Disinfectants-chemicals that kill bacteria on non-living substances. Ex) 409
List 2 kingdoms to which bacteria belong. Contrast these two kingdoms.
Archaebacteria: Ancient live in extreme environment cell wall lacks peptidoglycan Eubacteria: common bacteria live everywhere else cell wall contains peptidoglycan
Describe the three main shapes of bacteria- state the scientific term and meaning for each,
Bacilli- rod shaped bacteria Cocci- is sphere or circular shaped bacteria Spirilla- sphere shaped bacteria
What characteristic separates bacteria from all other living organisms?
Bacteria are prokaryotes and unicellular.
Compare and contrast the general structure of a bacterial cell and a virus.
Bacteria cell- Cell Nucleus Cell wall and cell membrane Virus- Particle No nucleus Core and capsid Both have DNA or RNA
How do bacteria reproduce? Name the process and list the basic steps involved?
Bacteria reproduce though the process of Binary fission. First the cell grows, then the DNA is copied, and then it splits into 2 cells.
List 5 bacterial diseases and 5 viral diseases.
Bacterial- Lyme disease Botulism Tuberculosis E. coli Salmonella Viral- .Ebola Flu virus Measles virus Polio HIV
List and explain the 4 methods bacteria have for obtaining energy and organic compounds.
Chemoheterotrophs- take in food for both energy and organic compounds, Photoheterotrophs- use sunlight for energy and obtain food for a source of organic compound, Photoautotrophs- use sunlight to make energy and organic compounds (glucose), Chemoautotrophs- Do not use light. Instead, use chemicals in their environment to make food and organic compounds.
List 4 major symptoms of shingles.
First, you get a tingling, itchy feeling or stabbing pain in the skin. Second, after a few days a rash appears as a band or patch of raised dots. Third, the rash turns into fluid-filled blisters. When the rash is at its peak, it can cause mild itching or even up to extreme and intense pain.
What is gram staining? What are the possible results when bacteria is gram stained? How does gram staining help a doctor prescribe a treatment for a bacterial infection? Be specific.
Gram staining is a method that identifies eubacteria by the makeup of their cell walls. It uses a dye to show doctors if the bacteria is Gram negative or gram positive. Gram negative means you have a thin cell wall of peptidoglycan, an additional layer of bacteria, blocks out many antibiotics, is not easily treated, and turns pink. This means it needs a heavier prescription. Gram positive means you have a thick cell wall of peptidoglycan, it's easily treated with antibiotics, and turns purple. This means the doctor would prescribe a lighter and more common prescription.
List 5 ways bacteria are beneficial to humans.
Help with digestion, make foods, make medicines, make paper, and helps with a process in the nitrogen cycle (nitrogen fixers)
What causes the virus to "reawaken" in people?
It is reactivated by people who have had the chickenpox virus before.
Would shingles be classified as following the lytic infection cycle or the lysogenic infection cycle? Explain.
It would be classified as the lysogenic infection cycle because it doesn't affect you right away. It becomes dormant and may or may not become active again.
Contrast the lytic reproduction cycle in viruses with the lysogenic reproduction cycle.
Lytic reproduction cycle: Examples- Common cold, flu Replicates immediately and kills the host cell. You get sick right away Lysogenic reproduction cycle: Examples- HIV, shingles Does not kill host immediately Viral DNA injected into host cell then fuses with host cell DNA You DO NOT get sick right away.
List and explain the 4 major roles bacteria play in the nitrogen cycle.
Nitrogen fixation- the first process and the nitrogen fixation bacteria changes nitrogen gas to ammonia. Nitrification- Then the ammonia that is not being used is turned into nitrate. Ammonification- this bacteria breaks down dead organisms and returning unused ammonia to the ground Denitrification- lastly, this bacteria converts ammonia that is not being used into nitrogen gas.
What organic compounds are found in a virus? Explain.
Nucleic acid and protein. Nucleic acid is found in the core and protein surrounds the core.
Difference between the following terms: Obligate aerobes, obligate anaerobes, facultative anaerobes.
Obligate aerobes- bacteria that require a constant supply of oxygen. Obligate anaerobes- bacteria that do not require oxygen. Facultative anaerobes- bacteria that can survive with or without oxygen.
State which characteristics or properties viruses have in common with living organisms.
The characteristics that viruses have common with living organisms are reproduction and heredity. They can only reproduce inside the host cell and they do have DNA or RNA.
What was the first antibiotic discovered and who discovered it?
The first antibiotic discovered was Penicillin and by Alexander Fleming.
What is the only organelle that bacteria have? Why do they have it?
The only organelle bacteria has are ribosomes. They have it because they need it to make protein.
What type of organisms can viruses infect? Why do viruses infect living things?
Viruses can infect any living organism. (Animals, plants, fungi, protists, and bacteria). Viruses infect living things because they need a source of energy to reproduce since they are not living themselves.
Explain how the outcome of binary fission differs from conjugation.
When binary fission is completed, it results in clones of the original copy. Bacteria also need a way to gain variation so that's why they use conjugation. In conjugation, the cells exchange DNA to obtain new traits=antibiotic resistance sometimes called transformation.
Hundreds of people get the "flu shot" each year. Yet many of them still get the flu. Why?
When people get the flu shot, it is treating one or two types of flu that scientists believe are most dominant for the current year. So, if people get the flu after their shot, it is most likely because that type of flu was not in the vaccine. Also, viruses are always changing and could disguise themselves as a different type of virus that the vaccine does not recognize.
What is the connection between chickenpox, shingles, and your nerve fibers?
You first get chickenpox, and it may later in your life get shingles. You can only get shingles if you have had chickenpox before. Most of the chickenpox virus will disappear, but some can survive, and travel up the nerve fibers along the spine where they lie dormant. It is possible to never get the shingles after getting chickenpox, but you're more prone to get it then a person who has never had chickenpox and has 0% chance of getting shingles.
