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BIOD 171 MODULE 6/ Portage Learning BIOD 171
Module 6 /Pathophysiology - BIOD 331 - Module 1
BIOD 151 Module 6 Expert-Reviewed Questions and
Answers
True or False. Because the genome is contained within an enclosed space (much like the nucleus of a cell), viruses are classified as eukaryotic. - -CORRECT ANS- -False True or False. Although viruses may contain their genome within an enclosed space (much like the nucleus of a cell), it is considered neither eukaryotic nor prokaryotic. - -CORRECT ANS- -True Describe the two basic components of a virus. - -CORRECT ANS- -A virus has genomic material made up of either DNA or RNA and a capsid which is a protective structure that contains genetic material True or False. You would expect to see a viral envelope on a virus infecting a bacterial cell. - - CORRECT ANS- -False The overwhelming majority of animal viruses are enveloped whereas the majority of plant or bacteria-infecting viruses are not. The envelope surrounds the _________ of some viruses. - -CORRECT ANS- -Capsid The ________ surrounds the capsid of some viruses. - -CORRECT ANS- -envelope Rank the following viruses based on their size from largest to smallest: Paramyxovirus Poliovirus
Smallpox virus - -CORRECT ANS- -Smallpox, Paramyxovirus, Poliovirus Rank the following viruses based on their size from largest to smallest: Orthomyxovirus Poliovirus Variolavirus - -CORRECT ANS- -Variolavirus Orthomyxovirus Poliovirus True or False: Highly infectious viruses undergo genome replication prior to viral attachment and entry. - -CORRECT ANS- -False 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: - -CORRECT ANS- -3- Uncoating: the viral capsid disassembles 5-Release: New virus particles are produced and leave the cell 4-Replication: the viral genome is the 'blueprint' to make copies of itself 1-Attachment: viral receptors bind to host proteins on the surface of the cell 2-Entry: the virus fuses with the host membrane and enters the cell 6-New infection: newly produced viruses that left the host cell now go on to infect new cells.
Based on the following image, would you expect the viral titer to be high or low? Why? - - CORRECT ANS- -Low, since the amount of intact bacterial cells in the media determines its turbidity, the amount of virus present in the tube has to be minimal. The amount of virus in the image is low. As the lytic cycle continues, more bacteria cells will be destroyed and the media will be cleared. Which of the following can be spread via airborne particles: Measles Mumps Rubella A and B All the above - -CORRECT ANS- -All the above True or False. A patient infected with rubella is only considered infectious when the trademark rash is visible. - -CORRECT ANS- -False A patient diagnosed with German measles may additionally experience what disease? Select all that apply.
- Impetigo
- Conjunctivitis
- Rheumatic fever
- Infleunza-like symptoms - -CORRECT ANS- -- Conjunctivitis
- Influenza-like symptoms Which of the following diseases does a linear, single-stranded RNA virus cause?
Measles Mumps Rubella B and C All the Above - -CORRECT ANS- -All the above What disease is best characterized by painful swelling of the paratoid? - -CORRECT ANS- -Mumps 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? - -CORRECT ANS- -You should keep a distance especially if your friend is coughing or sneezing because chickenpox can be transmitted through air-borne droplets. You should also avoid direct contact with the blisters of an infected individual. True or False. The development of shingles is most often seen in an older adult population (> 60 years old). - -CORRECT ANS- -True True or False. Unlike chickenpox, the blisters that appear with shingles are localized and limited to small areas. - -CORRECT ANS- -True True or False. Similar to chickenpox, the blisters that appear with shingles can cover the entire body. - -CORRECT ANS- -False 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. - -CORRECT ANS- -The person won't develop shingles, but will develop chickenpox. Unvaccinated and unexposed individuals have to develop chickenpox first because shingles is the reactivation of the dormant VZV virus from the chickenpox infection.
the flu? - -CORRECT ANS- -The flu shot is based upon the latest flu strains that circulate each year. You could come in contact with a viral strain that was not included in the flu vaccine that you received. True or False. The viral capsid of HIV is dumbbell shaped and contains ~2,000 copies of the viral protein p24. - -CORRECT ANS- -False True or False. The viral capsid of HIV is cone shaped and contains ~2,000 copies of the viral protein p24. - -CORRECT ANS- -True The HIV surface glycoprotein gp120 binds what host cellular receptor? CD CXCR CCR CD4 - -CORRECT ANS- -CD An individual infected with HIV is placed on anti-retroviral medication. What is the general purpose of this medication? - -CORRECT ANS- -the general purpose of anti-retroviral is to block the production of new viruses by preventing its integration and replication. True or False: The overwhelming majority of animal viruses are enveloped whereas the majority of plant or bacteria-infecting viruses are not. - -CORRECT ANS- -True True or False: viruses can be classified as prokaryotic or eukaryotic - -CORRECT ANS- -False. Viruses are neither prokaryotic or eukaryotic What is an obligate intracellular parasite? - -CORRECT ANS- -viruses cannot replicate unless inside a living host cell. As a parasite, a virus depends on its living host to provide the framework (proteins, etc) to replicate—to make additional copies of itself.
What is a viral capsid? - -CORRECT ANS- -a membrane-like protective structure that contains genetic material similar to nucleus of eukaryotic cells. What is the viral envelope, and what does the presence (or absence) of it tell you about the type of virus? - -CORRECT ANS- -The envelope surrounds the viral capsid, is derived from the host cell membrane and serves as an additional barrier to the external environment. The overwhelming majority of animal viruses are enveloped whereas the majority of plant or bacteria-infecting viruses are not. What type of microscope would be used to study the shape of a viral capsid? - -CORRECT ANS- - Due to its size (~30-150 nm) most viral capsids must be visualized via electron microscopy. How does the viral envelope both aid in cell entry as well as hide it from being detected by the immune system? - -CORRECT ANS- -The viral envelope contains the necessary proteins required for interaction with host cells. As the envelope is derived from the host cell membrane, this camouflages the virus and lowers the likelihood of immune detection by making it appear similar to the normal biological host cell. What must happen before viral replication of its genome can occur? - -CORRECT ANS- -For all viruses, the genome is replicated following attachment and entry, never before. Describe the basic steps of the viral life cycle. - -CORRECT ANS- -1. Attachment: Viral receptors bind to host proteins on the surface of the cell.2. Entry: The virus fuses with the host membrane and enters the cell3. Uncoating: (where applicable) the viral capsid disassembles4. Replication: The viral genome provides the 'blueprint' to make copies of itself5. Exit: New viruses are produced and leave the cell6. New infection: Newly produced viruses leave the host cell and go on to infect new cells. The process outlined above now restarts. What is a bacteriophage? - -CORRECT ANS- -A virus that infects bacteria
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. What are the two key glycoproteins found in the influenza virus? - -CORRECT ANS- -The viral envelope contains two key glycoproteins, hemagglutinins (HA) and neuraminidase (N). Hemagglutinins are heavily involved in the entry of the viral particle into a host cell, while neuraminidase proteins are involved in the budding and release of new viral particles from the host cell. Describe the composition of HIV. - -CORRECT ANS- -HIV contains two copies of single-stranded, linear RNA that is enclosed by a capsid. The conical capsid surrounds the two RNA strands and is comprised of ~2,000 copies of the viral protein p24. A viral envelope derived from the cell host membrane then surrounds the viral capsid. Within this envelope are two key glycoproteins, gp120 and gp41, which are essential for viral binding and entry into the host cell. What are the 2 basic components of a virus? - -CORRECT ANS- -1)genomic material comprised of DNA or RNA 2)capsid membrane-like protective structure that contains genetic material similar to nucleus of eukaryotic cells. Smallpox virus - -CORRECT ANS- -(variola virus) enveloped, 200nm long, dumbell shaped viral capsid Polio virus - -CORRECT ANS- -non-enveloped and 30 nm in diameter Paramyxovirus - -CORRECT ANS- -enveloped, spherical, single stranded, linear, and 100-150 nm in diameter, causative agent of measles and mumps, fuse with host cell membrane to initiate entry and viral replication. Orthomyxovirus - -CORRECT ANS- -causative agent of influenza, contains 8 segments of RNA and enters the host cell via endocytosis.
Virion - -CORRECT ANS- -a single virus particle and has a capsid and genetic material Why is the structure of a virion important? - -CORRECT ANS- -It dictates the host cell that the virion can infect. What are the 3 shapes of viral capsids? - -CORRECT ANS- -Helical, Icosahedral, Complex What are viral spikes? - -CORRECT ANS- -glycoprotein extensions on the capsid or envelop of a virion and helps identify and bind to a host cell, How do RNA vaccines work? - -CORRECT ANS- -They produce spike proteins so the immune system learns to identify the virus before patient gets sick. DNA viral genomes - -CORRECT ANS- --circular or linear -often double stranded -may also be single stranded RNA viral genomes - -CORRECT ANS- --linear or segmented -often single stranded -may also be double stranded Central Dogma of Molecular Biology - -CORRECT ANS- -DNA-transcription-RNA-translation- protein ssRNA (+) - -CORRECT ANS- -RNA is similar to host cells RNA so can be translated right into viral protein (polio, rubella, West Nile)
structure of bacteriophage - -CORRECT ANS- -icosahedral capsid head with genome, collar-helps sense the environment, sheath- contractile protein that produces a tube to move nucleic acides from the capsid to the host cell, base plate- important for interaction with the host cell, tail fibers- initiate binding to receptors on target cell 2 pathways for bacteriophage replication - -CORRECT ANS- -1) lytic 2) lysogenic lytic replication - -CORRECT ANS- -Replication cycle usually results in death and lysis of host cell, replicate all viral proteins needed for the assembly of new virus particles lysogenic replication - -CORRECT ANS- -used by temperate phages, integrated, cell division, lytic cycle, primarily exist in a non-replicative state that does not kill the host cell. genomes are integrated into the host genome but production of viral proteins is suppressed. How do you culture bacteriophages? - -CORRECT ANS- -Need bacterial cultures and bacteriophages, done in liquid or solid media viral titer - -CORRECT ANS- -quantity of virus present in a given volume of sample Turbidity - -CORRECT ANS- -cloudiness of water, when a virus and bacteria are intially combined in media the turbidity will be high because the bacteria cells have not been lysed yet, but as the virus lyses the bacterial cells, the solution will become clearer due to the lower amount of bacterial cells present. When do you measure turbidity? - -CORRECT ANS- -Before and after you add the bacteriophage in. Epidemiology - -CORRECT ANS- -number of infections in a population or area where infection attends to occur
Transmissability - -CORRECT ANS- -ability to be transmitted from one host to another Skin manifestations of viruses - -CORRECT ANS- -1) primary- one associated with a specific disease 2) secondary lesion rash - -CORRECT ANS- -widespread outbreak of lesions Vesicular rash - -CORRECT ANS- -Vesicles; fluid filled blisters (e.g. herpes, chicken pox) Maculopapular rash - -CORRECT ANS- -rash with a flat red area that also has raised bumps (rubella and measles) Rubella - -CORRECT ANS- -German measles (togaviridae virus) a viral infection characterized by a low-grade fever, swollen glands, inflamed eyes, and a fine, pink rash, transmitted bu aerosols, treatment: MMR vaccine Rubeola - -CORRECT ANS- -measles, virus: paramyxoviridae, transmitted via respiratory droplets, fever sore throat, Koplik's spots, maculopapular rash, treatment: MMR vaccine epidemic parotitis - -CORRECT ANS- -mumps, affects digestive system, enveloped linear single stranded RNA paramyxovirus, transmitted by respiratory droplets and salive, MMR vaccine Chickenpox (Varicella) - -CORRECT ANS- -enters through respiratory tract and migrates to blood, liver, spleen, lymph nodes, then moves from blood to skin producing lesions What happens when latent particles of chicken pox reactivate? - -CORRECT ANS- -shingles develop
Neuraminidase - -CORRECT ANS- -One of the enzymes found on the surface of the Influenza virus. 9 subtypes Hemagluttin - -CORRECT ANS- -on virus. binds to receptors on epithelial cells and causes endocytosis of virus 16 subtypes antigenic drift vs antigenic shift - -CORRECT ANS- -drift: mutations in HA and N proteins that occur during replication shift: every 10 years or so major changes seem to occur in antigens and creates epidemic, when strains jump species and are able to infect humans Coronavirus Associated Infections - -CORRECT ANS- -SARS, MERS, SARS-CoV-2 (Covid 19) prevention: recombinant vector vaccine or mRNA vaccine Recombinant vector vaccines - -CORRECT ANS- -a gene for a pathogens antigens is inserted into a love but non-pathogenic viral vector mRNA vaccine - -CORRECT ANS- -mRNA encoding for the viral protein is inserted into a liposome which fuses with cells near the injection site (COVID 19 vaccine contains antigen coronavirus spike protein) AIDS (acquired immune deficiency syndrome) - -CORRECT ANS- -Immune system disease caused by the Human Immunodeficiency Virus (HIV) which over a period of years weakens the capacity of the immune system to fight off infection so that weight loss and weakness set in and other afflictions such as cancer or pneumonia may hasten an infected person's demise What is the definition of "pathophysiology"? - -CORRECT ANS- -Pathophysiology is defined as not only the cellular and organ changes that occur with disease, but also the effects that these changes have on total body function. Name the 5 etiologic factors and give an example if listed. - -CORRECT ANS- -Etiologic factors are the causes of a disease.
- Physical forces: trauma, burns, etc
- Chemical agents: poisons, alcohol
- Biological agents: bacteria, viruses
- Genetic predisposition: inherent genes from both parents but you don't necessarily develop the disease but are predispositioned to it
- Nutritional excess or deficiencies: Iodine deficiency can lead to hypothyroidism. Nutritional excess in carbohydrates can lead to irritable bowel syndrome. What are the 2 types of risk factors? - -CORRECT ANS- -Congenital: present at birth Acquired: occur after birth What is the difference between morphology and histology? - -CORRECT ANS- -Morphology is defined as the fundamental structure or form of cells or tissues. Histology is the study of the cells and extracellular matrix of body tissues. Describe the difference between signs and symptoms and give an example of each. - -CORRECT ANS- -These both relate to manifestations of a disease. Signs is an objective manifestation while symptoms are a subjective complaint. Signs are apparent to the physician, symptoms are apparent to the patient. What are 3 important processes when coming to a diagnosis? - -CORRECT ANS- -Patient history, diagnostic testing, and a physical examination. Explain validity, reliability, sensitivity, and specificity. - -CORRECT ANS- -Validity: how a tool measures what it is intended to measure i.e. the correct tool to do the job, such as using a blood pressure cuff to measure blood pressure Reliability: likelihood of yielding the same result of a test, usually dependent on someone's experience and skill level Sensitivity: proportion of people with a disease who test positive Specificity: people without the disease who test negative for it
Name 3 structures within the nucleus. - -CORRECT ANS- -Chromatin, nucleolus, and nuclear envelope What are the roles of the ribosomes, rough ER, and smooth ER? - -CORRECT ANS- -Ribosomes synthesize proteins. Rough ER carries ribosomes and synthesizes lysosomal enzymes. Smooth ER NO RIBOSOMES. Creates lipids, lipoproteins, and steroid hormones. What is the function of the lysosomes, peroxisomes, and mitochondria? - -CORRECT ANS- - Lysosomes break down proteins. Peroxisomes break down free radicals through the secretion of an enzyme that breaks down peroxides. Mitochondria are the power house of the cell. They transform organic compounds into cellular energy. What is contained in the cytoskeleton and what is its function? - -CORRECT ANS- -The cytoskeleton contains a network of microtubules, microfilaments, intermediate filaments, and thick filaments. They control cell shape and movement. Explain microtubules. - -CORRECT ANS- -Microtubules can disassemble at one location and reassemble at another, aiding in the maintenance of cell form, intracellular transport, and the formation of cellular structures. Explain centrioles. - -CORRECT ANS- -Centrioles are made of microtubules and aid during cell division by forming the mitotic spindle and helping to separate and move the chromosomes. Explain cilia. - -CORRECT ANS- -The cilia are also made of microtubules and function in cell motility.
Give examples of where cilia and flagella are found in the human body. - -CORRECT ANS- -Cilia are found in epithelial lining such as nasal passages. Flagella are only found in sperm. What are the 4 functions of the cell membrane? - -CORRECT ANS- -The cell membrane separates the contents of a cell from its outside environment. It regulates the materials coming into and going from the cell, it aids in cell division and growth, and contains hormone receptors that facilitate the conduction of electrical currents in nerve receptors. Why do cells need to communicate with one another? - -CORRECT ANS- -Cells need to communicate to sense and respond to changes in their environment, this cannot be done without communication. Name the 4 types of signaling. - -CORRECT ANS- -Endocrine, paracrine, autocrine, and synaptic signaling What is endocrine signaling? - -CORRECT ANS- -hormones in the bloodstream signal for cells to act on the body What is paracrine signaling? - -CORRECT ANS- -enzymes metabolize chemical mediators and leads to cell acting on a nearby cell What is autocrine signaling? - -CORRECT ANS- -cell releases chemical into extracellular fluid that affects its own self What is synaptic signaling? - -CORRECT ANS- -occurs in nervous system. Neurotransmitters act on adjacent nerve cells through synapses, or small gaps between nerve cells What is up regulation? - -CORRECT ANS- -Up regulation is when a cell increases its response to a substance or signal from outside the cell to carry out a specific function. A cell may increase the number or activity of protein receptors or other molecules on its surface to make it more sensitive to a hormone or drug.
