Microbe Mission Test, Exams of Environmental science

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Whiting

Invitational

Science Olympiad

Div C

Microbe Mission

(Winter, 2023)

Team #__________ Name:_______________________________ Name:_______________________________

Whiting Invitational Microbe Mission Event Division C Winter 2023 Instructions: You may mark on this event testing packet if you would like to do so. You MUST write ALL answers on your answer sheet in order for them to be scored and for you to receive credit.

1. Basic Microscopy - For each type of microscope listed, choose both the correct description (number) and the correct example image (letter). a. Brightfield __________ b. Phase-Contrast ____________ c. Confocal____________ d. Electron ___________ Descriptions: 1. Uses visible light; good for objects no smaller than .2μm; used for simple stains and cell counts.
2. Uses a single photon to illuminate one plane of a specimen at a time; used in biomedical research.
3. Uses a beam of charged particles that either pass through a Specimen or are reflected off of it, depending on type; used to view specimens smaller than .2μm; useful for studying internal structures of cells and viruses.
4. Uses a special condenser, with a diaphragm, along with a diffraction plate; both direct and indirect light are used to an unstained, but clearly detailed, specimen image; used to observe the internal anatomy of unstained specimens. Sample Images: a. b. c. d.

5. Following up from question #4, which chemical is a counterstain? a. Gram’s Iodine b. Safranin c. Crystal Violet d. Alcohol
6. Identify the Gram-negative sample from the following images. a. b.
7. Acid Fast Staining was developed as a method to test for the presence of what specific bacteria? a. Escherichia coli b. Bacillus anthracis c. Mycobacterium tuberculosis d. Treponema pallidum
8. Which dye(s) is/are used in an Acid Fast Stain? a. Methylene Blue b. Carbol Rose c. Crystal Violet d. Carbol Fuchsin e. Gram’s Iodine

9. Bacteria which respond well to Acid Fast Staining contain a high concentration (60% or greater) of what lipid in their cell walls? a. Cholesterol b. Mycolic acid c. Histidine d. Estrogen 10.A fastidious bacteria would be preferentially grown on what type of media? a. Differential Media b. Synthetic Media c. General Purpose Media d. Enriched Media 11.Part of a bacterial growth curve is shown below. Using discipline correct terminology, identify the portion of the curve between 100 and 200 minutes. ________________ 12.3 common bacterial morphologies are shown. Identify each using correct discipline specific terminology. a. _________________

15.Algae are photosynthetic eukaryotes whose cells contain the photosynthetic organelles called chloroplasts. In what part of the chloroplast do we find the enzyme ribulose bisphosphate carboxylase ( Rubis CO)? a. Intermembrane space b. Thylakoid membrane c. Thylakoid space d. Stroma 16.2 common soil bacteria are grown in separate broth cultures. Bacteria “A’s” broth contains carbon, nitrogen, phosphorus, and potassium. Bacteria “B’s” broth contains carbon, nitrogen, and potassium. Replication in these 2 cultures is measured at 5-hour intervals and the resulting growth curve data is shown in table 1. Table 1. Based on the data collected, phosphorus could be considered a _______________________ for Bacteria “B.” 17.Like algae, cyanobacteria make use of chlorophyll a for light absorption to power photosynthetic processes. Green Sulfur Bacteria, by contrast, use pigments called bacteriochlorophylls ( c, d, and e ) for photosynthesis. These molecularly different chlorophyll molecules allow Green Sulfur Bacteria to harvest light energy without releasing _______________ into the environment. a. Glucose b. Oxygen c. Water d. Carbon Dioxide

18.Following from the previous question, what term do we use to describe bacterial photosynthesis that does not use water as an electron donor, and does not release (answer to #17) into the environment? a. Bacterialphototrophic b. Anoxygenic c. Anhydrogenic d. Hydrophototrophic 19.The 2 alternative cycles (Lytic and Lysogenic) for bacteriophage reproduction are shown in Figure 1. Correctly identify the Lysogenic Cycle in this diagram (A or B). Figure 1.

20. Following up from the previous question, identify the Lytic Cycle ( A or B) in Figure 1. __________ 21.The image below (Figure 2) shows a “loop” of bacterial genetic material that is separate from the main bacterial chromosome. This piece of genetic material is readily transferred from 1 bacterium to another, and the R-type of

Figure 3. a. Flagella b. Cilia c. Fimbriae d. Pili 25.Following from question #24, longer versions of these structures are used by prokaryotes to exchange genetic material and are called… a. Flagella b. Cilia c. Fimbriae d. Pili 26.Should nutrients within its environment become depleted, the bacterium in Figure 3 could form a specialized “resting” cell called an ____________. a. cyst b. glycocalyx

c. plasmid d. endospore 27.Members of the Domain Archaea are found in a wide range of habitats across the globe. What they are best known for are their extremophile phyla. Of the extremophile “groups” listed, which would you most likely find inhabiting The Great Salt Lake in Utah, or the Dead Sea (between Israel and Jordan)? a. Halophiles b. Thermophiles c. Methanogens d. Psychrophiles 28.Following up to question #26, which group of extremophiles could you find within the digestive tract of ruminant animals, such as cows? a. Halophiles b. Thermophiles c. Methanogens d. Psychrophiles 29.Cell-to-cell contact between prokaryotic cells that results in the transfer of genes, usually via plasmid DNA, is called ________________. a. Transformation b. Conjugation c. Transduction 30.The transfer of host genes from one cell to another using a virus as the mechanism of transfer is _____________________. a. Transformation b. Conjugation c. Transduction 31.The transfer of bacteria genes from one cell to another using free DNA; this term is also used for the process by which a normal cell becomes a cancer cell. _______________________. a. Transformation b. Conjugation c. Transduction

d. The agar and phosphate buffers used to make the solid growth media generate byproducts that kill many microbes when they are autoclaved separately. 37.Identify the plate inoculation and counting method shown in Figure 4. Figure 4. Method:______________________________ 38.Identify the plate inoculation and counting method shown in Figure 5. Figure 5. Method:__________________________________

39.Using table 2 (below), determine the “index per 100 ml” and the “upper and lower 95% confidence limit values for the sample method results shown in Figure 5 (question #38). Table 2 Index/100ml ________ Upper _________ Lower _________ 40.Which plate counting method involves a petri plate being inoculated with bacteria cultured in a broth medium, followed by the addition of agar that has been maintained in a 50℃ water bath? a. Spread Plate b. Filtration c. Pour Plate d. Turbidity