Exam 1 Study Question Answers

Exam 1 Study Question Answers - EXAM ONE Study Questions...

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EXAM ONE Study Questions MCB 410 Spring 2011 Lecture 2 1. What are the three main branches of life? - Bacteria (eubacteria). - Archaea (archaebacteria). - Eucaryotes. 2. Name six organelles in the cell and describe their primary function. 1. Chloroplast ( plastid ): photosynthesis. 2. Endoplasmic reticulum: translation and folding of new proteins (rough endoplasmic reticulum), expression of lipids (smooth endoplasmic reticulum). 3. Golgi apparatus: sorting and modification of proteins. 4. Mitochondria : energy production. 5. Vacuole : storage, helps maintain homeostasis . 6. Nucleus : DNA maintenance, RNA transcription . 3. What is the evidence that mitochondria and chloroplasts were separate organisms at one time? - Where did eucaryotes come from? The eucaryotic, bacterial, and archaean lineages diverged from one another very early in the evolution of life on Earth. Some time later, eucaryotes are thought to have acquired mitochondria; later still, a subset of eucaryotes acquired chloroplasts. Mitochondria are essentially the same in plants, animals, and fungi, and therefore were presumably acquired before these lines diverged. 4. Describe a cellular process or an organelle that is best seen with A light microscope: The internal structures of a living cell can be seen with a light microscope. A cell taken from human skin and grown in tissue culture was photographed through a light microscope using interference-contrast optics. The nucleus is especially prominent. A pigment cell from a frog, stained with fluorescent dyes and viewed with a confocal microscope. The nucleus is shown in blue, the pigment granules in red, and the microtubules—a class of filaments built from protein molecules in the cytoplasm—in green. An electron microscope: Mitochondria are among the most conspicuous organelles in the cytoplasm. These organelles have a very distinctive structure when seen with an electron microscope: each mitochondrion appears sausage- or wormshaped, from one to many micrometers long; and each is enclosed in two separate membranes. The inner membrane is formed into folds that project into the interior of the mitochondrion. Scanning electron micrograph of the stereocilia projecting from a hair cell in the inner ear. A scanning electron microscope: S catters electrons off the surface of the sample and so is used to look at the surface detail of cells and other structures.
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A fluorescence microscope : Dividing nuclei in a fly embryo seen with a fluorescence microscope after staining with specific fluorescent dyes. A confocal microscope: A confocal microscope is a specialized type of fluorescence microscope that builds up an image by scanning the specimen with a laser beam. An intact insect embryo is shown stained with a fluorescent probe for actin (a filamentous protein). 5. What is the difference between resolution and contrast?
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This note was uploaded on 03/10/2011 for the course MCB 410 taught by Professor Ward during the Spring '08 term at University of Arizona- Tucson.

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Exam 1 Study Question Answers - EXAM ONE Study Questions...

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