MICR 2420 Complete Study Exam Questions With Correct Detailed Answers.

Three domains of life - correct answer Eukarya, Bacteria, Archaea Which kingdoms contain unicellular organisms? - correct answer Bacteria and Archaea Which kingdoms contain multicellular organisms? - correct answer Plants and Animals (including fungi) Robert Hooke - correct answer - Built the first compound microscope - 30x power - Observed and drew nematoes, mites, and mold sporangia - Coined the term cell Antoine Van Leeuwenhoek - correct answer - Experimented with grinding v powerful lenses - 500x magnification - First person to observe single celled organisms - Called them animalcules Edward Jenner - correct answer Introduced vaccination against smallpox with cowpox scabs Lazzaro Spallanzani - correct answer Displayed that broth sterilized by boiling failed to grow microbes. People argued it was due to lack of oxygen Louis Pasteur - correct answer - Chirality - Fermentative metabolism - Used swan necked flasks to disprove spontaneous generation - Flame under flask, heat sterilization can prevent microbial growth - Microbes arise from pre existing microbes - Developed first vaccine based on attenuated strains of microbial pathogens Florence Nightingale - correct answer - Founder of medical epidemiology - Demonstrated that infection caused more morbidity than any other condition during the Crimean war - Persuaded more hygienic conditions Robert Koch - correct answer - Specific microbes cause specific diseases - Started with anthrax to determine chain of infection What are Koch's 4 postulates and what are they used for? - correct answer Koch's 4 Postulates: Defining the causative agent of disease 1) Microbe is found in cases of disease; not in healthy people 2) Microbe is isolated from diseased host and grown in a pure culture 3) When microbe introduced in a healthy host, disease ensues 4) Same strain obtained from newly diseased host Defining the causative agent of disease. Ignaz Semmelweis - correct answer Hand washing an important process for physicians Joseph Lister - correct answer Clean (free from microbes) operating areas for his patients Alexander Fleming - correct answer - Discovered Penicillin Howard Florey & Ernst Chain - correct answer - Purified penicillin - Inhibits formation of bacterial cell wall Dimitry Ivanovsky - correct answer Causative agent of TMD is smaller than known microbes Martinus Beijernick - correct answer Agent of disease could not be bacterial cells Wendell Stanley - correct answer Processed 4000 kg of tobacco leaves and purified infection virus by crystallography What are the four aspects of a microbe? - correct answer - Requires a microscope to be seen - 0.2 micrometer to mm - Unicellular - Contains in genome capacity to reproduce its own kind What are the three exceptions to the microbial definition? - correct answer 1) Some bacteria can be seen with the naked eye 2) Some bacteria live in complex communities - are they still considered unicellular? 3) Viruses are non cellular particles containing genetic material Fred Sanger - correct answer Developed DNA sequencing method Metagenome - correct answer Environmental collection of sequences, microbes isolated from natural environment, computational strategy Microbial ecologists - correct answer Studying microbes in their natural habitat What were 3 of Sergei Winogradsky's contributions? - correct answer Among the first to study bacteria in their natural habitat 1) Lithotrophs 2) Enrichment cultures 3) Winogradsky column Lithotrophs - correct answer Microbes that metabolize inorganic minerals instead of organic nutrients like the microbes isolated by koch Earnest Haeckel - correct answer Microscopic organisms constitute a third group, neither animal nor plant Monera Herbert copeland - correct answer Monera divided into two groups - Eukaryotic protists (protozoa and algae - Prokaryotic bacteria Lynn Margulis - correct answer Endosymbiosis Carl Woese - correct answer - Discovered archaea using 16s RNA subunit - Molecular clock Frederick Griffith - correct answer Transformation Oswald Avery + Team - correct answer Genetic material for transformation is DNA Light microscopy - correct answer Resolves images by their absorption of light Electron microscopy - correct answer Uses beams of electrons to resolve Atomic force microscopy - correct answer Uses intermolecular forces between a probe and object to map 3D topography of a cell or cell parts X-ray Crystallography - correct answer Detects interference pattern of X-ray entering the crystal lattice of a molecule Chemical imaging microscopy - correct answer Applies mass spectroscopy to a microscopic object. Eg microbe is bombarded with beam of ions that vaporizes organic molecules from the objects surface, fragments identified through mass analysis. Bright-Field microscope - correct answer Produces a dark image against a brighter background How many objective lens/lenses does a bright field microscope have and how of you calculate total magnification? - correct answer Several objective lenses Ocular X Objective = Total Magnification Compound microscope - correct answer Composed of objective lens system (short focal distance) and ocular of eyepiece system (longer focal distance-lower magnification) Lenses - correct answer - Focus light rays at focal point What is the strength of the lens related to? - correct answer Focal length. Shorter focal length means higher magnification. Microscope resolution. What is a big factor in this and what is the relationship? - correct answer Ability of lens to separate or distinguish small objects that are close together. Wavelength is a great factor, smaller wavelength higher resolution. Three steps to observing specimen under comp