Environmental Microbiology Test 1 PDF - Carlos Beardall

# Environmental Microbiology Test 1 ## Carlos Beardall **Date:** 16/09/24 **Max. 60pts** **56/60** **93%** ## Section 1: Matching Match the word(s) in **Column A** with the appropriate answer in **Column B**. Write the letter in the **Answer** column. (15pts) | Answer | Column A...

# Environmental Microbiology Test 1 ## Carlos Beardall **Date:** 16/09/24 **Max. 60pts** **56/60** **93%** ## Section 1: Matching Match the word(s) in **Column A** with the appropriate answer in **Column B**. Write the letter in the **Answer** column. (15pts) | Answer | Column A | Column B | | :------- | :--------------------------------- | :--------------------------------------------- | | K | no cell wall | A. gram positive | | E | movement in eukaryotes | B. pili | | I | cell identification | C. lytic | | L | amoebas | D. mastigophora | | L | pseudopeptidoglycan | E. cilia | | 0 | chytrids | F. penicillium | | M | prophage | G. gram negative | | ✓ | ascomycota | H. Pilobolus | | J | thin periplasmic space | I. glycoproteins | | L | basidiomycota | J. lysogenic | | F | zygomycetes | K. mycoplasmas | | 妈 | cell destruction | L. sarcodina | | A | thin peptidoglycan | M. water molds | | N | euglenas | W. rust and smuts | | H | conjugation | Ø. archaea | ## Section 2: True and False (10pts) 1. Spherical bacteria arranged in chains are all streptococci. **True** 2. During the death phase of the bacteria growth cycle bacteria is reproducing. **True** 3. During the LOG phase of the bacteria growth cycle the bacteria stores nutrients for when conditions are not favorable. **False** 4. The LAG phase can be extended by adding more nutrients to the culture. **False** 5. Plasmodial slime molds survive in the environment by forming a multicellular structure that differentiates into a spore producing structure. **True** 6. The plasmodium that causes malaria is an example of a sporozoan. **True** 7. Edward Jenner was the scientist who discovered antibiotics. **False** 8. The pili of the bacteria aids in microbial attachment. **False** 9. Bacteria produces excretory substances that plays a significant role in soil formation. **True** 10. Natural Attenuation speeds up the process by which bacteria biodegrades organic matter. **False** ## Section 3: Fill in the Blanks (14pts) 1. Two Spherical shape bacteria join together is called a **diplo cocci** 2. Bacteria whose glycocalyx is not fixed and firmly attached to the cell wall outer most layer is called a **slime layer**. 3. Peptidoglycan is made up of the disaccharides **NAG** and **NAM** 4. The process by which bacteria feeds on dead bacteria is called **endogenous metabolism** 5. The two major class of chytrids are the **water molds** and **slime molds**. 6. The fusion of the cytoplasm during the sexual life cycle of the fungi is called **plasmogamy** while the fusion of the nucleus is called **karyogamy** 7. Antibiotics are made from fungi belonging to the phylum **Ascomycota** 8. Symbiotic relationship between a fungi and the roots of leguminous plants is called a **mycorrhizae** 9. Bacillus anthraces is studied in modern microbiology under the field called **bacteriology** 10. Gram negative bacteria has a **pink** color after the gram staining test is carried out while gram positive has a **purple** color. ## Section 4: Multiple Choice (9pts) 1. What are normal flora? * a. bacteria that normally cause disease * **b. microbes that live on and in your body that don't normally cause you harm** * c. bacteria that can be grown in lab in bacterial cultures * d. bacteria that is normal in shape and size 2. Spontaneous generation is associated with which of the following: * a. aseptic techniques * **b. life from life (pre-existing cells)** * c. germ theory of disease * d. life from non-living materials 3. Louis Pasteur: * a. was the first person to view microorganisms with a hand-held lens and became the Father of Microbiology * **b. developed antiseptic surgery techniques** * c. developed the postulates that explained how to prove the "germ" theory of disease for most infectious agents * d. was able to eliminate contamination of wine in France by a process now called pasteurization 4. Joseph Lister: * a. was the first person to view microorganisms with a hand-held lens and became the Father of Microbiology * **b. developed antiseptic surgery techniques** * c. developed the postulates that explained how to prove the "germ" theory of disease for most infectious agents * d. was able to eliminate contamination of wine in France by a process now called pasteurization 5. Which of the following is an example of bioremediation? * a. use of Saccharomyces cerevisiae to make wine * b. use of cowpox virus to vaccinate against smallpox * **c. use of Pseudomonas to remove uranium from soil at weapons depots** * d. use of Bacillus thuringiensis to kill crop-eating insects 6. All the following are characteristics of gram positive bacteria EXCEPT: * a. Thick peptidoglycan layer * **b. outer membrane** * c. Thin periplasm * d. Teichoic acid 7. Association of fungi with roots of plants are called * a. lichen * **b. mycorrhizae** * c. Nodule * d. mycelium 8. A wildlife pathologist is examining some skin tissue from a dead frog. She notes the presence of a fungus. Upon culturing the fungal cells she notices that some of the cells are flagellated. She concludes that the frog has a fungal disease caused by * a. An ascomycete * b. a zygomycete * c. a basidiomycete * **d. a chytrid** 9. You are walking in the woods and see a fungus that is unfamiliar to you. You remove a reproductive structure, and take it home to examine further. When you look at it under the microscope, you find sac-like structure with 8 spores. Based on this information alone, this fungus is a(n) * **a. ascomycete** * b. zygomycete * c. basidiomycete * d. chytrid ## Section 5: Short Answers (6pts) 1. Give 2 ways in which bacteria/fungi/protist are structurally adapted to survival in the environment. (BE SPECIFIC) * **Bacteria:** - Can form a relationship with a virus that benefits both. While the bacteria acts as a host for the virus, the virus forms a bacteriophage which protects the bacteria from being consumed by protists. - Bacteria has structures that enables them to adhere or attach to a surface, preventing them from being carried away. For instance the sticky glycocalyx as well as the cilia. They also have a cell membrane (semi-permeable) phospholipid layer that controls what goes in and out of the cell. * **Fungi:** - Fungi have an extensive root system that allows them to form a symbiotic relationship with the roots of other plants, with both benefiting from nutrients. - The spores they produced are somewhat toxic/harmful. This helps to keep predators away from them. These spores also allow for a quick and efficient reproduction process. * ****Protist:** - Some protists are equipped with flagella that allows them to move from one place to another (move away from danger or towards food). Others have false feet and move by means of pseudopodia. - Euglenas have what is called a red eye spot, which aids in the process of photosynthesis (obtain/make their own food) 2. Differentiate between the lytic and lysogenic cycle * **Lytic cycle:** Begins when the virus attaches itself to the host cell. Following attachment, the virus will inject its genetic material whether DNA or RNA into the host cell, hijacking its entire machinery. After hijacking, the virus will then begin to replicate and assemble. When the conditions are right, the newly formed viruses will be released into the environment. * **Lysogenic cycle:** The lysogenic cycle begins when the virus attaches itself to the host cell and inject its genetic material into the host cell. The key difference is that the viral genetic material does not hijack the host cell's machinery (it forms a bacteriophage). When the host cell divides, the genetic material of it and the virus will replicate, however, no new viruses will form. The viral replicates can remain dormant for a long period of time, and when the conditions are right, they are triggered to enter the lytic cycle. - **Lytic:** - Cell machinery destroyed - **Lysogenic:** - Prophage formed (cell machinery intact) - **Bacteriophages** ## Section 6: True and False (10pts) 1. Microbial flocs reduces the challenges of disease like early mortality syndrome (EMS). **True** 2. In general water probiotics does not reduce chances of disease, as well as limit the duration of existing disease outbreaks. **False** 3. Water probiotics incorporate bacteria strains in the feed pellet using many types of binders, such as egg white and fish oil, for more efficient application. **False** 4. Under intensive culture, variations in salinity may break homeostasis and lead to significant stress, slow growth, low survival rate, and thus, high economic loss in penaeid shrimp. **True** 5. Maintaining DO is important to reduce the occurrence and/or minimize the impacts of disease outbreaks. **True** 6. Overstocking decreases stress among the stock of shrimp, having the common visible adverse impact to be retarded growth. **False** 7. Most aquatic organisms prefer a neutral pH range of 7.5-9.5. **False** 8. Nonpoint-source pollution can decrease the amount of dissolved oxygen in water, which can be harmful to fish and other aquatic organisms. **True** 9. High concentration of nitrates decrease algae growth and cause a decrease in dissolved oxygen which impacts aquatic life. **False** 10. Open Oceans have relatively low primary productivity because of low levels of essential nutrients nitrogen and phosphorus except when water from bottom brings up nutrients with currents. **True** ## Section 7: Definitions (10pts) 1. A **microbiome** is a collection of microbes that form a unique ecology within a distinct habitat - usually an individual animal or fish. 2. **Gut probiotics** are live microbial feed supplements which provide beneficial effects for the intestinal balance of the host animal. 3. **Competitive exclusion** is the process where probiotic bacteria can multiply and proliferate in the water, making it difficult for the pathogenic bacteria to compete for resources, which reduces the levels of pathogens in the water. 4. **Symbiotics** combining probiotics with the traditional technique of prebiotics. 5. **Turbidity** is a measure of the clarity of a water body and is related to erosion and sedimentation which impacts streams and lakes. 6. Two bioindicators used to determine the quality of freshwater are **aquatic macro-invertebrates and algae.** 7. **Benthic habitat** is a transition zone between the water column and the mineral surface where the organic material that settles from the water column is or that is deposited from the terrestrial environment is collected. Characterized by high microbial concentration. 8. **Microbial mats** is an interfacial aquatic habitat in which many microbial groups are laterally compressed into a thin mat of biological activity. 9. **Biofilm** is a layer of organic matter and microorganisms formed by the attachment and proliferation of bacteria on the surface of an object. 10. **Microbial loop** is a term used to describe a trophic pathway in aquatic environments where dissolved organic carbon (DOC) is reintroduced to the food web through the incorporation of bacteria.