Virus Explorer Worksheet

INTRODUCTION What do the flu, HIV, and coronaviruses have in common, and how are they different? You’ll learn more about these and other viruses in the Virus Explorer Click & Learn. In the Click & Learn, you can explore the structures and biology of 10 different viruses, as well as how these viruses impact humans and other organisms. PROCEDURE Follow the instructions as you proceed through the Click & Learn, and answer the questions in the spaces provided. 1. Open the Virus Explorer Click & Learn and click on the “About” tab at the bottom. Use the information in this tab to answer the following questions. a. List four ways in which viruses can differ from each other. Viruses differ and can be categorized by structure, genome type, host type, and the transmission mechanism. b. In the table below, describe what each abbreviation in this Click & Learn means. Abbreviation Description nm nanometer bp base pairs ss single-stranded ds double-stranded 2. Close the “About” tab and return to the main page. Find the “i” icon next to each viral characteristic across the top. Click on each icon to learn more about that characteristic, then answer the associated question below. a. Envelope: The envelope is an outer layer that some, but not all, viruses have. How does an envelope form? An envelope forms by exiting the host cell by budding from the cell membrane or another similar surface, and in the process part of the membrane wraps around the virus, forming the envelope. b. Host(s): From the virus’s perspective, why is the host important? Virus Explorer The host is essential because it is how the virus replicates. Without hosts there is no possible place for viruses to replicate. c. Genome Type: What are four characteristics of viral genomes that may vary among viruses? The four characteristics are split into two main categories, the first being the type of nucleic acid. This is either DNA or RNA (which is further classified by + or - ). Then they vary by the number of strands, making them either double or single stranded. d. Transmission: Define the terms “vector” and “zoonotic.” A vector is an organism that acts as an intermediate transmitter for the virus, which it utilizes to hop from one host to another one. Zoonotic means that said virus was transmitted from an animal to humans. e. Vaccine Availability: What is one advantage of being vaccinated against a particular virus? Being vaccinated allows for your body to be prepared to properly battle against a virus when it enters your body, preventing you from experiencing symptoms, and having the virus use you as a host. 3. Click the viral characteristics across the top of the main page to classify and learn more about the viruses. Use what you learn to answer the following questions. a. What is one difference between the rabies virus and the influenza A virus? One difference between these two is how the Rabies virus is unable to infect and use birds as a host while Influenza A can utilize them as a host. b. Of the 10 viruses shown, which is the only one that infects plants? TMV or the Tobacco Mosaic Virus is the only plant that is able to infect plants. c. List three characteristics that adenoviruses, T7 virus, and papillomaviruses have in common. All three are naked, meaning they do not have an envelope, they all have double-stranded DNA, and they all are similar in their relative sizes. d. As of 2020, a new coronavirus called SARS-CoV-2 has been in the news. There have been many efforts to develop a vaccine for this coronavirus. Why is this virus of particular concern? This virus is of a particular concern because it spread extremely easily and quickly to those with no immunity. e. Which two viruses infect all the vertebrates included in the Click & Learn? The adenovirus and the Papillomavirus are the only two to infect all vertebrates. Virus Explorer f. Of the 10 viruses shown, which is the only one that infects bacteria? The T7 virus is the only one that infects bacteria. g. List four specific characteristics that human immunodeficiency virus (HIV) and Ebola virus have in common. Both are enveloped, infect humans as hosts, are transmitted from human-to-human, and both have similar replication cycles. h. List four specific characteristics that HIV and Ebola virus do not share. They are of vastly different sizes as Ebola is twice the size of HIV, HIV only can infect humans, while Ebola can infect all mammals. They have different genome types, Ebola has -ssRNA while HIV has +ssRNA. 4. Find the + icon next to each virus’s name. Click on each icon to learn more about that virus, then answer its associated question(s) below. a. Rabies: People often think that you get the rabies virus from dogs. Why is this understanding incomplete? This is incomplete because the rabies virus is transmitted not only by infected dogs but by foxes, racoons, skunks, and bats. b. Influenza A: Influenza viruses have a segmented genome. Why is having a segmented genome an advantage for these viruses? This separation helps then because it can create a new virus subtype during replication as two or more of the viruses can combine segments that are brand new. c. HIV: HIV infects cells in the immune system. Why is this a disadvantage for the infected person? This harms the infected person because they are losing cells that help them fight against disease, so if they get infected they won’t be able to fight it off. d. Ebola: What animal is associated with Ebola virus outbreaks? Bats are commonly associated with the outbreaks we have seen. e. Tobacco mosaic virus (TMV): Name one characteristic of TMV that none of the other viruses in the Click & Learn have. This virus has the ability to infect plants and transmits itself from one plant to another. Virus Explorer f. Adenovirus: What are three of the many conditions that adenoviruses can cause in humans? They can cause the common cold, bronchitis, and pink eye. g. T7 virus: The replication cycle of T7 virus has several things that none of the other virus replication cycles include. What is one of these things? They inject their DNA into the host cell rather than having the entire viral structure be engulfed by the cell. h. Papillomavirus: What is the common name for papillomas? They are commonly known as warts. i. Zika: Why is Zika virus of great concern to pregnant women? Zika is especially concerning for pregnant women because it can lead to microcephaly and neurological defections in their children. j. Coronavirus: What are the names of two coronaviruses that caused outbreaks in humans before 2020? The two coronaviruses that caused outbreaks before 2020 were the SARS-CoV-1 in 2002 and the MERS-CoV in 2012.