BIOD 171 Portage Learning Final EXAM Questions and Answers 100%Correct/Exam 1-7 2023/2024 Update

BIOD 171 Portage Learning Final EXAM Questions and Answers 100%Correct/Exam 1-7 2023/2024 UpdatePortage Learning BIOD 171 Final EXAM Questions and Answers 100%Correct/Exam 1-7 2023/2024 Update True or False: A virus is considered a microorganism. False. Viruses are not living and as such are not considered microorganisms. Viruses can, however, be classified as microbes, a more general term that includes microorganisms and viruses. 1. What is the smallest biological unit of life? A cell. 2. At a generalized level, all cells are comprised of what? Macromolecules* *A student may also answer: Proteins, Lipids, Nucleic acids and Polysaccharides but they must answer with all four to be fully correct. 1. Which of the following microorganisms are considered to be Eukarya? Select all that apply. A. Animalia B. Plantae C. Fungi D. Protista A,B,C,D 2. True of False: All multicellular microorganisms classified as Animalia are heterotrophic. True 3. Microorganisms classified as Plantae obtain most of their energy by converting energy into energy. Light (sunlight); chemical (sugars) 1. Define catabolism. Catabolism is the process of breaking down larger molecules into useful energy sources. 2. Upon cellular injury, which metabolic process is involved during the growth and repair phases of the cell? The anabolic process would be active as it (by definition) is involved in the building up of small complexes into larger complexes. 1. In phosphorylation, the light reactions always occur where? The process of converting light energy into chemical energy (photophosphorylation) always occurs in the membrane. 2. True or False: The Calvin cycle must occur in the absence of light. False. The term ‘dark reactions’ (also known as the Calvin Cycle) simply denotes the second stage in photosynthesis—dark reactions do not actually require darkness in order to occur. 1. Assuming a constant (non-adjustable) light source power, identify the part of the microscope you would adjust to limit the amount of light entering the microscope. Select all that apply. A. Objective B. Condenser C. Iris diaphragm D. Eye piece C. The iris controls the amount of light that passes through the sample and into the objective lens. Thus, it can be adjusted (opened or closed) to alter the amount of light. 2. What is the total magnification (relative to your eye) of a sample imaged with a 60x objective and a 10x eyepiece? Show your math. 60 x 10 = 600x magnification 1. Identify what type of electron microscope was used to capture the following image and explain your choice. The image was captured using a Scanning Electron Microscope (SEM). The above image shows the trademark ‘shell’ image (no subcellular organelles are visible) reminiscent of SEM. Only TEM is capable of visualizing subcellular substrucutres. 1. True or False: LB agar is classified as a selective, non-differential media. False. LB agar is the most basic type of agar and like LB media supports the growth of virtually all microbes without restriction. 2. What is agar used for in microbiology? Agar is used to create a solid, smooth surface on which microbes can grow. 1. True or False. When performing a dilution streak a new (or sterilized) loop is not required for each phase as long as the bacterial culture is pure. False. 2. The number of phases (3 vs. 4) and/or the number of times a loop passes through a previous phase (once vs. multiple times) is acceptable provided what happens? Either deviation is acceptable in practice provided the resulting gradient contains within it the growth of individual colonies—if not, the experiment must be repeated. 3. True or False. Pathogenic strains of bacteria tend to grow slower than normal non-pathogenic bacterial strains. False. 1. Match the following symptoms with their respective diseases: 1. Folliculitis D 2. Scalded-skin syndrome E 3. Impetigo A 4. Conjunctivitis B A. Childhood skin disease near mouth/ nose B. Infection of thin, transparent scleral tissue C. Infection occurs at time of birth D. Pus-filled lesions on skin or hair 5. Ophthalmia Neonatorum C E. Ruptured pustules; treated with Penicillin 2. True or False. The causative agent of conjunctivitis can be either bacterial or viral. True. 1. True or False. There are currently no cures for tetanus. True. 2. Identify the medical condition characterized by robust carbohydrate fermentation under anaerobic conditions, swelling of the infected areas and fever. Gas gangrene. The key identifier here is the robust carbohydrate fermentation, which manifests as intense gas production and swelling—both trademark conditions of gas gangrene. 3. The alpha-toxin perfringolysin is associated with which medical condition caused by Gram-positive anaerobic bacteria? A. Tetanus B. Botulism C. Gas gangrene D. Leprosy C. Gas gangrene. The bacterium that produces the alpha toxin perfringolysin is aptly named Clostridium perfringens. 1. The envelope surrounds the of some viruses. Capsid. 2. True or False. You would expect to see a viral envelope on a virus infecting a bacterial cell. False 3. Rank the following viruses based on their size from largest to smallest: Paramyxovirus Poliovirus Smallpox virus Smallpox (~200nm) Paramyxovirus (100-150nm) Poliovirus (~30nm) 1. What linear, double-stranded, enveloped DNA virus is the first virus (as of Oct. 26, 1977) to be officially declared eradicated? Smallpox (Variola virus). Although once a major cause of death in the world, a smallpox vaccine was developed in 1796 by Edward Jenner. Global vaccination efforts have prevented smallpox from appearing in humans since October 26, 1977, making smallpox the first infectious disease ever to be eradicated. 2. What small (~30nm) single-stranded, non-enveloped RNA virus targets the CNS (central nervous system), causing potentially catastrophic damage to motor neurons? Polio, also known as poliomyelitis. 3. By whom and where was the first Polio vaccine developed? Jonas Salk and his research team developed the polio vaccine at the University of Pittsburgh in 1955. 4. Which subtype of Influenza is the most virulent? Influenza A. Module 1 Exam Exam Page 1 1. True or False: A virus is classified as a microbe. True 2. True or False: The smallest biological unit of life is the molecule. false 3. What are the 4 main types of macromolecules found in cells? Proteins, nucleic acids, polysaccharides, and lipids Exam Page 2 1. How many different types of amino acids are available from which to make proteins? There are 20 different types of amino acids. 2. Define an essential amino acid. Amino acids are known as the primary structure of protein. 9 out of 20 of the amino acids are considered essential amino acids and cannot be produced by the human body but is found in the environment in other ways, such as the foods you consume. Exam Page 3 1. Where can the two major types of nucleic acids be found in the cell and what are their roles? DNA- contains a lot of hereditary information which is responsible for the characteristics of living organisms that can be inherited. It is found in the nucleus but cannot leave the nucleus. RNA- deciphers the hereditary information in DNA which is used to synthesize proteins. It is found in the nucleus but can also leave the nucleus. Exam Page 4 1. Complete the following DNA strand and indicate how many bonds are formed for each complementary pair: 3’ GGTCATCG 5’ 5’ CC AGC 3’ AGT. A-T pairings results in 2 hydrogen bonds. C-G pairings results in 3 hydrogen bonds. Exam Page 5 1. The plasma membrane (select all that are true): A. Only restricts movement of materials into the cell B. Is often a bilayer comprised of lipids C. Cannot prevent essential nutrients from escaping D. Contains hydrophobic tails pointing inward 2. Carbon, Hydrogen and Oxygen atoms come together to form what primary macromolecule? Give an example. They come together to form polysaccharides. An example would be sucrose. 1. True of False: Eukaryotic cells do not have a nucleus False. Eukaryotic cells do have a nucleus (prokaryotic cells do not). 2. True or False: Prokaryotic cells can be subdivided into Bacteria and Archaea. True 3. Describe the 4 basic bacterial morphologies. Coccus (round/spherical), bacillus (rod), vibrio (curved rod) or spirillum (spiral/corkscrew). 4. True or False: Archaea, a eukaryotic class of microorganisms, are capable of surviving harsh environments. False. Exam Page 7 1. Which of the following microorganisms are considered to be Eukarya? Select all that apply. A. Animalia B. Plantae C. Fungi D. Protista 2. True of False: All multicellular microorganisms classified as Animalia are heterotrophic. True 3. Microorganisms classified as Plantae obtain most of their energy by converting energy into energy. light energy (sunlight), chemical energy (sugars) Exam Page 8 1. A defining characteristic of fungi is the presence of chitin in the cell walls. Which of following also contain chitin? Select all that apply. A. Mushrooms B. Bacteria C. Yeast D. Molds 2. True or False: A defining characteristic of Protista is the inability of colonies to form tissue layers. true Exam Page 9 1. Cell walls are found in which of the following (select all that apply): A. Plants B. Fungi C. Bacteria D. Mammalian cells E. Algae 2. The function of the ribosome is (select all that apply): A. Lipid synthesis B. Protein synthesis C. To produce energy (ATP) D. Protein modification and distribution E. Waste disposal via hydrolytic enzymes Exam Page 10 1. Identify the following cellular components by matching the number with the description. A. Rough endoplasmic reticulum B. Golgi apparatus C. Nucleus D. Cell wall E. Plasma membrane F. Centriole G. Lysosome 1C 2G 3E 4B 5A Module 2 Exam 1. True or False: Metabolism is a controlled set of biochemical reactions that occur in living organisms in order to maintain life. True. 2. True or False: Enzymes are polysaccharides that catalyze chemical reactions. False. Enzymes are proteins that catalyze chemical reactions. 3. What are usually metal ions known to assists enzyme during the catalysis reaction? Cofactors are usually metal ions and assist enzyme during the catalysis reaction. 1. Define catabolism. It is a process that allows larger molecules to be broken down into useful energy sources. 2. Upon cellular injury, which metabolic process is involved during the growth and repair phases of the cell? The anabolic process because it is involved with building up small complexes into larger complexes. Exam Page 3 1. Describe the energy transfer process relative to both ATP and ADP. ATP gives energy whereas ADP accepts energy to become ATP. During the donation of energy, ATP transfers energy from the breakdown reactions which is used for building up. This fuels cells to carry out necessary biochemical reactions for survival. 2. From what source do chemotrophs acquire energy? From chemicals that already exist in the environment. 3. An organism that obtains its source of carbon from inorganic molecules such as carbon dioxide is referred to as a ? autotrophs 4. This phosphorylation process occurs in the mitochondria of chemotropic eukaryotes. A. Photophosphorylation B. Substrate-level phosphorylation C. Oxidative phosphorylation 1. Identify the products of the following chemical equation: Glucose + 2NAD+ → 2 NADH + 2 Pyruvate + 2 ATP Glycolysis produces pyruvate molecules, NADH molecules and ATP. 2. What are the main two roles of glucose-6-phosphate in the cell? prevention of glucose from diffusing out of the cell is the signal molecule to the cell that glycolysis is going to begin soon. 3. True or False: During fermentation one means of eliminating pyruvate is by converting it into lactic acid. true 1. What is the primary byproduct of the TCA cycle? Select all that apply. A. NAD+ B. FAD C. NADH D. FADH2 c & d 2. True or False. The reactants of the TCA cycle directly enter and fuel the electron transport system. false 1. In the absence of glucose, which of the following can be used as alternative energy sources? Select all that apply. A. Lactose B. Nucleic acids C. Carbohydrates D. Lipids A, C, D can all be used as alternative energy sources. 2. For the catabolism of proteins and lipids, which of the following enzymes are used? Select all that apply. A. Ligases B. Proteases C. Transferases D. Lipases B and D. Proteases breakdown proteins while lipases breakdown lipids. 3. True or False. The β-oxidation pathway catabolizes the fatty acid chains of lipids. True 1. Describe the relationship between chloroplasts and chlorophyll. Chloroplasts are double membrane enclosed organelles that are specified for algae and plants. It also houses chlorophyll, which is the photosynthetic pigment. 2. True or False: Chloroplasts are specific to algae and plants. true 3. The process of photophosphorylation produces which of the following: select all that apply. A. ATP B. Glyceraldehyde-3-phosphate C. CO2 D. NADPH E. H2O a & D 1. In phosphorylation, the light reactions always occur where? In the membrane 2. True or False: The Calvin cycle must occur in the absence of light. False 1. How many turns (or repititions) of the Calvin Cycle are required to generate one molecule of glucose? 6 2. Complete the following equation by placing the appropriate numbers where indicated. CO2 + ATP + NADPH + H20 → C6H12O6 + ADP + NADP+ 6CO2+ 18ATP+ 12NADPH+ 12H2O → C6H12O6+18ADP + 12NADP+ 1. Match the following reactions to its corresponding enzyme: 1. A + B → A-B 2. A-B → A + B 3. A¯ + B →A + B¯ 4. Ab + C → A + Cb A- Lyases B- Transferases C- Oxioreductaces D- Hydrolases E- Ligases F- Isomerases 1E 2A 3C 4B Module 3 Exam 1. A micrometer is defined as A. 10-3 B. 10-6 C.10-9 D. 10-12 B 2. True or False: A nanometer is longer than a micrometer. False 1. Resolution and contrast are two critical factors that influence your ability to see an object. Explain each. • Resolution: refers to the distance between 2 objects where the objects can still be seen separately. The closer 2 objects are to one another, you'll need higher resolution to continue viewing the objects separately. • contrast: the difference of how light is absorbed between 2 objects. The lower the contrast between an object and it's background, the harder it'll be to see it. 1. Assuming a constant (non-adjustable) light source power, identify the part of the microscope you would adjust to limit the amount of light entering the microscope. Select all that apply. A. Objective B. Condenser C. Iris diaphragm D. Eye piece c 2. What is the total magnification (relative to your eye) of a sample imaged with a 60x objective and a 10x eyepiece? Show your math. 60x* 10x= 600X 1. True or False: A cell that is adherent, flat (thin) and unstained is easily identified using bright field microscopy. false 2. Which of the following could be seen clearly by the unaided eye? Select all that apply. A. Bacteria with diameter of 24 µm B. Protozoa with diameter of 150 µm C. Virus with a diameter of 0.2 µm D. Skin cell with diameter of 1500 µm b & d 1. Label the following unmarked microscope components (numbered arrows) by matching it with the components provided (letters). A. Stage B. Fine Adjustment Knob C. Iris Diaphragm D. Neck E. Condenser Lens F. Eyepiece G. Objective H. Base I. Coaxial Controls 1F 2D 3B 4G 5A 6H 1. For each of the following questions select from the list below the single best answer: Phase-Contrast Dark Field Fluorescence Confocal This type of microscope is best suited for visualizing GFP, RFP and YFP proteins. Fluorescence 2. This type of microscope can provide detailed images of live cells without staining. phase contrast 3. This type of microscope is used to greatly increase the contrast between samples and background by reflecting light off of the specimen. dark field 4. This type of microscope is capable of capturing images in multiple focal planes, rendering a specimen in 3D confocal 1. Identify what type of electron microscope was used to capture the following image and explain your choice. Transmission electron microscope, this is because it can shows the nanoparticle as a 2D image. There isn't as much detail as would be shown in a scanning electron microscope. 1. Gram-Positive cells appear in color due to a peptidoglycan layer in the cell wall. purple, thick 2. Gram-Negative cells appear in color due to a peptidoglycan layer in the cell wall. pink, thin 1. True or False: The distinguishing characteristic of Gram-Negative bacteria is the presence of LPS in the outer membrane. true 2. True or False: If you wish to study the motility of an organism you cannot heat fix, but you can chemically fix the specimen. false 1. You want to observe the size and shape of a cell. What is the easiest staining technique that you could perform? Name at least one dye you would use during this process. Simple staining- the dyes that could be used are methylene blue, crystal violet, safranin, or fuschin. 2. You suspect a patient may have TB. Once a sample has been obtained it is sent off to the lab for an acid- fast stain. If the patient were infected with TB, describe what you would expect to see on the stained slide. I would expect to see the causative agent of TB to show up in red, which is when the carbolfuchsin dye is retained. 3. True or False: A Giemsa stain can be used to determine the presence of pathogenic bacteria. true Module 4 Exam 1. True or False: Differential media is best suited for distinguishing between two similar species of bacteria. True. Growth media does not contain restrictive factors, while selective media is best used to encourage the growth of one microbe while simultaneously discouraging the growth of the other. Since two similar species of microbes are being studied they must be differentiated under similar but just slightly different conditions (differential media). 2. A researcher is asked to determine if a sample contains Neisseria meningitides. Knowing Neisseria meningitides is slow growing and other foreign microbes may also be present in the culture, which type of media would be best suited: A. Growth media B. Differential media C. Selective media D. Selective and Differential media 1. True or False: LB agar is classified as a non-selective, non-differential media. True. LB agar is the most basic type of agar and like LB media supports the growth of virtually all microbes without restriction. 2. The polysaccharide-based hardening agent added to LB media to produce LB agar is derived from what? Seaweed (algae) extract. 3. Blood agar is which type of medium? A. Differential B. Selective C. Enriched D. Selective and Differential A. and C. Blood agar can be used to differential between species based on its hemolytic activity. It is enriched with red blood cells. 1. Match the following hemolytic class with its description of activity. 1. Alpha hemolysis b A. No hemolytic activity 2. Beta hemolysis c B. Incomplete hemolytic activity 3. Gamma hemolysis a C. Complete hemolytic activity 1. Columbia CNA agar is used to isolate: A. Gram-Negative B. Gram-Positive C. Mycobacteria D. Gram-Positive and Gram-Negative 2. True or False: Chocolate (cocoa) is not a component of Chocolate agar plates. True. The name is derived simply based on the color that actually comes from the presence of ‘cooked’ (lysed) red blood cells in the media. 3. An unknown microbe is streaked onto a MacConkey agar plate. After an overnight incubation at 37C, growth is observed. Would a Gram stain be necessary? Why or why not? No. A Gram stain would not be necessary, as only Gram-Negative microbes will grow on MacConkey agar. 1. In an attempt to detect the presence of the pathogenic strain of E. coli O157:H7, a researcher spread a culture onto a MacConkey agar with failed results. What type of agar should they (correctly) try next? Why? Sorbitol-MacConkey because it contains lactose and sorbitol. E coli isn't able to ferm sorbitol which is why you'll be able to differentiate non- pathogenic strains of the E. Coli. 1. In Eosin Methylene Blue (EMB) agar, what color indicates the presence of E. coli? green 2. Which type of agar media is best suited to support the growth of Staphylococcus? A. MacConkey agar B. Blood agar C. Columbia CNA agar D. Mannitol salt agar E. Chocolate agar. 1. What is the process of spreading a bacterial culture onto a petri dish? It is called plating. 2. In order to visual individual colonies of bacteria would you culture your sample in a liquid media or on a solid (agar) media? Why? Solid because as they grow the microbes form colonies which will take on the appearance of individual isolated dots. 3. True or False? The visualization of colonies on a petri dish represents bacterial cells that have often multiplied a million times over. true 1. True or False. The purpose of a quadrant streak is to produce individual colonies of a bacterial population. true 2. A dilution gradient is formed when carrying out what generalize plating strategy? quadrant streak 3. In what phase of a dilution streak would you expect to find the highest concentration of bacteria, P2 or P4? P2 1. True or False. When performing a dilution streak a new (or sterilized) loop is not required for each phase as long as the bacterial culture is pure. false 2. The number of phases (3 vs. 4) and/or the number of times a loop passes through a previous phase (once vs. multiple times) is acceptable provided what happens? Either is acceptable as long as the result of the gradient contains a growth of individual colonies. If this doesn't occur the experiment has to be repeated. 3. True or False. Pathogenic strains of bacteria tend to grow slower than normal non-pathogenic bacterial strains. false When given an unknown bacterial sample the first step is to expand the current bacterial population. Which form of media best suites this need? Why? A. MSA agar B. LB media containing ampicillin and neomycin C. MacConkey agar D. Blood agar D. Blood agar. All other options (A, B and C) are all forms of selective media, meaning they may potentially inhibit the growth of the unknown sample. Although blood agar is considered a differential media, it is, most importantly, a non-selective media. Given the alternatives, this is the best option. Module 5 Exam 1. Define the concept of universal precautions. This means that any and all samples, whether they are known or unknown, must be treated as potentially hazardous or pathogenic materials. 2. List at least 3 observations a researcher would be sure to note while assessing an unknown microbial sample. 1. morphological characteristics, size & shape 2. if there are any observable motility when view under the microscope 3. to capture images of any characteristics above or manually draw the observations, if possible. 1. While observing an unknown sample of limited amounts, a researcher must determine the following observations: (1) the presence of any motility and (2) its Gram status using the same sample—the liquid sample cannot be divided. Which would you determine first and why? The presence of any motility would be determined fist because the sample cannot be divided. 2. A facultative anaerobe is a microorganism capable of growth under what conditions? Under both aerobic and anaerobic conditions, with and without oxygen. 1. As Streptococcus is catalase negative would it thrive or die in the presence of peroxides? Why? It would die because it is catalase negative. Strep cannot breakdown peroxides. 2. Streptococcus is most often streaked onto A. Chocolate agar B. EMB agar C. Blood agar D. Spirit Blue agar 3. True or False. The Lancefield groups are used to subdivide antigenic groups of gamma-hemolytic Streptococcus. false 4. Greater than 90% of all human streptococcal infections belong to: A. Group B B. Group D C. Group A D. Group C 5. Left untreated, strep throat can progress to , which displays hemolytic activity. A. Strep. Pharyngitis; beta B. Strep. Septicemia; gamma C. Rheumatic fever; beta D. Strep. Pharyngitis; alpha 1. True or False. Under most circumstances, staphylococcus can be found in ~80% of human population where it remains non-symptomatic. false 2. Define commensal bacteria. There is so affect to its host- it neither harms nor benefits from the host that it gets its nutrients from. If the immune system is compromised, the amount of colonized staphylococcus can quickly expand which can lead to serve illness. 3. How can Staphylococcus be differentially tested? The species are capable of growth when bile salts are present. 1. Match the following symptoms with their respective diseases: 1. Childhood skin disease near mouth/nose C A. Folliculitis 2. Infection of thin, transparent scleral tissue D B. Scalded-skin syndrome 3. Infection occurs at time of birth E C. Impetigo 4. Pus-filled lesions on skin or hair A D. Conjunctivitis 5. Ruptured pustules; treated with Penicillin B E. Ophthalmia Neonatorum 2. True or False. Staphylococcus is the only causative agent of conjunctivitis. False. There are bacterial (staph) and viral forms of conjunctivitis, both resulting in the inflammation of the conjunctiva and ‘pink eye.’ 1. True or False. An acid-fast stain is best suited to identify Tuberculosis (as opposed to a Gram stain). true 2. True or False. Although TB must be inhaled and reside in the lung in order to cause infection, TB can also spread to the brain, spine and kidneys. true 1. Only directly ingesting the pre-formed Clostridium toxin (neither the bacteria nor its spores) will cause disease in adults. True. The mature (adult) microbiota is capable of killing the bacteria/spores. 2. While visiting his grandparents, a 10-year-old child has green beans for dinner that were harvested from his grandparents’ garden and canned the previous year. Severe illness sets in and the child is taken to the hospital. Botulism is suspected, but what form? Explain your answer. Foodborne botulism. The child is too old ( 6 months) to be considered for infant botulism and wounds were not present. The green beans were likely improperly canned and under the low-acidic, anaerobic conditions, bacterial growth was encouraged. 1. True or False. Although there is no cure for tetanus, it can be prevented through vaccination. true 2. Describe the symptoms and treatment regimen for someone infected with Clostridium perfringens. Perfringolysin is an alpha-toxin produced by perfringes, and it is an induced toxicity characterized by muscle necrosis, swelling of infected areas, fever and intense gas production. 3. Why does the alpha toxin (perfringolysin) produced during an infection of gas gangrene cause cell death? It causes cell death because the production of gas leads to further cell damage, also known as necrosis, which leads to an even bigger invasion of the pathogenic bacteria. Treatment involves removal of all infected tissue, which can often result in amputation of the affected areas. 1. You develop a fever, chills and pneumonia after recently using a warm midst vaporizer in an attempt to open your sinuses. What bacterial disease would a doctor suspect is causing your symptoms? Would the doctor suspect you contracted it from touching (potentially) contaminated doorknobs? Legionaire's disease. No, it would be cause by contaminated man made water systems, like the warm midst vaporizer. 2. True or False. Bubonic plague is often characterized by painfully swollen lymph nodes. true 3. Which form of the plague is highly virulent? What does it target? Pneumonic. It targets the respiratory system/lungs. 1. Identify the following disease: A. Tetanus B. Scalded-skin syndrome C. Lyme disease D. Gas gangrene 2. Syphilis is caused by: A. Diplococcic bacteria B. Staphylococcus bacteria C. Gram-Negative spirochete D. RNA virus 3. True or False. Chlamydia is an obligate parasite and as such can be grown on agar plates alone. false 4. Match the following diseases with their respective symptoms if left untreated: Gonorrhea c Syphilis a Chlamydia e A. Paralysis, blindness and dementia B. Painfully swollen lymph nodes C. Cardiac and neurological complications D. Respiratory failure associated with lock-jaw E. Infertility and pelvic inflammatory disease. F. Sore throat, ocular discharge and fever Module 6 Exam 1. True or False. Because the genome is contained within an enclosed space, (much like the nucleus of a cell) viruses are classified as eukaryotic. false 2. Describe the two basic components of a virus. 1. Genomic material that's made up of either DNA or RNA 2. Capsid, a membrane-like protective structure that holds the genetic material 1. The surrounds the capsid of some viruses. Envelope 2. True or False. You would expect to see a viral envelope on a virus infecting a plant cell. False. The overwhelming majority of animal viruses are enveloped whereas the majority of plant or bacteria-infecting viruses are not. 3. Rank the following viruses based on their size from largest to smallest: Orthomyxovirus Poliovirus Variolavirus Variolavirus (~200nm) Orthomyxovirus (100-150nm) Poliovirus (~30nm) 1 . True or False: Highly infectious viruses undergo genome replication prior to viral attachment and entry. false 2. Place the following viral life cycle steps in order beginning with viral attachment and provide a description of each step. Uncoating: Release: Replication: Attachment: Entry: New infection: 1. attachment: viral receptos bind/adhere to host proteins that are on the exterior of the cell. 2. entry: the virus joins with the host membrane and enters the cell 3. uncoating: the viral capsid dismantles, where applicable 4. replication: the viral genome gives something similar to a blueprint in order to make copies of itself 5. new infection: produced using the host cellular parts- which includes enzymes, proteins, etc., which then come together to assemble new viral particles 6. release: viruses that are newly released then exit the cell. 1. A virus that infects bacteria is called a and contains a -side polygon capsid. bacteriophage, 20-sided 2. True or False. Structurally, bacteriophages are distinct from viruses that infect plant or animal cells. true 3. Identify the following components of a bacteriophage. 1-Capsid (or Head) 2-Collar 3-Tail (sheath) 4-Base plate 5-Tail fibers 1. Describe the main differences between lytic and temperate phages. Lytic bacteriophages replicate within the host bacteria until it ruptures, whereas temporate (or lysogenic) phages primarily exist in a non-replicative state that does not kill the host cell. Lytic phages replicate all viral proteins needed for the assembly of new virus particles whereas lysogenic phage genomes are integrated into the host genome but production of viral proteins is suppressed. Lytic phages replicates within their host bacteria until it breaks where it then destroys its host cell. Temperate phages can exist where it doesn't replicate and it viral genome will integrate into the host genome. 2. Based on the following image, would you expect the viral titer to be high or low? Why? Low. As turbidity is a function of the number of intact bacterial cells present in the media, the amount of virus contained within the above tube must be low. As the lytic cycle continues more and more bacterial cells will be destroyed, effectively clearing the media. 1. Which of the following cannot be spread via airborne particles: A. Measles B. Mumps C. Rubella D. A and B E. None of the above 2. True or False. A patient infected with Rubella is considered infectious one week before and after the appearance of the trademark rash. true 3. Which of the following diseases does a linear, double-stranded DNA virus cause? A. Measles B. Mumps C. Rubella D. B and C E. None of the above 4. What disease displays as a secondary characteristic swelling of the testes/ovaries and pancreas? mumps 5. A patient diagnosed with German measles may additionally experience what disease? Select all that apply. A. Impetigo B. Conjunctivitis C. Rheumatic fever D. Influenza-like symptoms 1. You go to visit a friend who has chickenpox. While visiting what are 2 things you will be sure to avoid so that you don’t also become infected? Visit after the the rash appears and the formation of scabs are over the blisters. Because it can be transmitted through sneezing and coughing wearing a mask could be beneficial. 2. True or False. Someone who had chickenpox as a child is likely to develop shingles while in college, where the median age of college students is 18-22 years old. false 3. True or False. Similar to chickenpox, the blisters that appear with Shingles can cover the entire body. false 4. A person who has neither previously had chickenpox nor been administered the VZV vaccine is exposed to someone with an active VZV (shingles) outbreak and becomes infected. Explain why (or why not) the person will only develop shingles. No, the person would NOT develop shingles, they would develop chickenpox because once the small blisters that are formed from the red patches it is possible to infect some that hadn't already been exposed to VZV. 1. While traveling abroad, should you be worried about coming into contact with either the Variola major or Variola minor viruses? No, vaccinations have prevented smallpox from showing up in humans since 1977. 2. What small (~30nm) single-stranded, non-enveloped RNA virus causes temporary or permanent paralysis by infiltrating (infecting) motor neurons within the spinal cord, brain stem or motor cortex? Polio 3. Described the main underlining differences between the Salk and Sabin polio vaccine. Salk's vaccine was given as an injection and Sabin were drops, which made Sabin the preferred choice. 4. Which subtype of Influenza is the most virulent? Influenza A virus 1. A drug company is trying to develop a new drug that will inhibit the release of newly produced viral particles. Would the drug company target hemagglutinin proteins or neuraminidase proteins? Why? Neuraminidase proteins because they are involves with the the release of new viral particles that come from the host cell. 2. Explain why the flu shot given each year may not be 100% effective at preventing the flu? The flu shot is unlikely to be 100% effective because there are a high number of variants the flu vaccine isn't ablate vaccinate against all subtypes. Medical researchers predict and then distribute the flu vaccines based on the strains that are most common. 1. True or False. The viral capsid of HIV is dumbbell shaped and contains ~2,000 copies of the viral protein p24. false 2. The HIV surface glycoprotein gp120 binds what host cellular receptor? A. CD3 B. CXCR4 C. CCR5 D. CD4 3. An individual infected with HIV is placed on anti-retroviral medication. Describe how the medication will affect the virus. This medication will affect the virus by fighting off its ability to reproduce. If it goes untreated the chances are high that the infection will become AIDS.