Biology 2e
2nd Edition
ISBN: 9781947172517
Author: Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher: OpenStax
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Chapter 21, Problem 22CTQ
The first electron micrograph of a virus (tobacco mosaic virus) was produced in 1939. Before that time, how did scientists know that viruses existed if they could not see them? (Hint: Early scientists called viruses “filterable agents.”)
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Students have asked these similar questions
Which of the following highly contagious viruses is a single-stranded ribonucleic acid (RNA) virus with a helical capsid and envelope and is transmitted by coming in contact with respiratory secretions?
"This is a highly contagious respiratory illness transmitted when an infected person coughs or sneezes virus particles into the air," the health department said in a written statement. "It's so contagious that if one person is sick and spreading measles, nine out of 10 people around them who aren't immune will get it, too."
Group of answer choices
a. Measles
b. Parvovirus
c. Coxsackie virus A
d. Rhinovirus
Researchers have recently discovered giant viruses that are 1 μm in length, the same size as some bacterial cells. The genomes of these viruses contain over 2 million base pairs of DNA, which is more DNA than is found in many bacterial genomes, and their genomes contain hundreds—in some cases, thousands—of genes. Given these observations and what you know about viruses, should viruses be considered living or nonliving? Give arguments for and against considering viruses as living organisms.
Select all the following statements that are TRUE regarding viruses:
□ All viruses are potentially dangerous to humans because any virus can infect any host.
□ Viruses are fastidious pathogens that require complex growth media.
□ Viruses are noncellular particles that take over the metabolism of a cell to generate more virus particles.
□ Viruses are genomes made of RNA and DNA that lack many protein.
□ Viruses can infect all other known life forms on earth, from Archaea to humans.
Chapter 21 Solutions
Biology 2e
Ch. 21 - Figure 21.5 Which of the following statements...Ch. 21 - Figure 21.8 Influenza virus is packaged in a viral...Ch. 21 - Figure 21.10 Which of the following statements is...Ch. 21 - Which statement is true? A virion contains DNA and...Ch. 21 - The viral______play(s) a role in attaching a...Ch. 21 - Viruses. all have a round shape cannot have a long...Ch. 21 - The observation that the bacteria genus Chlamydia...Ch. 21 - A scientist discovers a new virus with a linear,...Ch. 21 - Which statement is not true of viral replication?...Ch. 21 - Which statement is true of viral replication? In...
Ch. 21 - Which statement is true of reverse transcriptase?...Ch. 21 - Oncogenic virus cores can be. RNA DNA neither RNA...Ch. 21 - Which is true of DNA viruses? They use the host...Ch. 21 - A bacteriophage can infect the lungs viruses...Ch. 21 - People with the CCR5?32 mutation of a T-cell...Ch. 21 - An apple grower notices that several of his apple...Ch. 21 - Which of the following is NOT used to treat active...Ch. 21 - Vaccines. are similar to viroids are only needed...Ch. 21 - A patient presents at the clinic with an acute...Ch. 21 - Which of the following is not associated with...Ch. 21 - Which statement is true of viroids? They are...Ch. 21 - The first electron micrograph of a virus (tobacco...Ch. 21 - Varicella-zoster virus is a double-stranded DNA...Ch. 21 - Classify the Rabies virus (a rhabdovirus family...Ch. 21 - Why can’t dogs catch the measles?Ch. 21 - One of the first and most important targets for...Ch. 21 - In this section, you were introduced to different...Ch. 21 - Although plant viruses cannot infect humans, what...Ch. 21 - A bacteriophage with a lytic life cycle develops a...Ch. 21 - Why is immunization after being bitten by a rabid...Ch. 21 - The vaccine Gardasil that targets human papilloma...Ch. 21 - Prions are responsible for variant Creutzfeldt...Ch. 21 - How are viroids like viruses?Ch. 21 - A botanist notices that a tomato plant looks...
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- As a general rule, viruses are not considered to be alive based on several reasons. One such reason is that some viruses use RNA as their genetic material instead of DNA. Which of the five biological themes does this violate? Briefly explain why.arrow_forwardStudent J and K were arguing about viruses and bacteria. Student K said that it would be easy to tell viruses and bacteria apart by just growing them in a lab and looking at them under a microscope. Student J said there were major flaws in that idea. What are the flaws in Student K’s idea?arrow_forwardA new virus has recently been discovered that infects human lymphocytes. The virus can be grown in the laboratory using cultured lymphocytes as host cells. Design an experiment using a radioactive label that would tell you if the virus contains DNA or RNA.arrow_forward
- A particular animal virus requires the use of DNA polymerase from its host, since it does not possess its own DNA polymerase enzyme. Which of the following assumptions in A-D would likely be correct regarding this virus? A) O This virus could not be a retrovirus type. B) OIt could be a (-) ss RNA virus. C) O It could be a (+) ss RNA virus. D) O The vVirus life cycle very likely includes going to the host cell nucleus. E) O All ofA-D are correct assumptions.arrow_forwardDiscuss the following statement: “Viruses exist in the twilight zone of life: outside cells they are simply dead assemblies of molecules; inside cells, however, they are alive.”arrow_forwardWhich of the following statements about viruses is true?a) They contain DNAb) They contain RNAc) They contain proteind) They are susceptible to lipid solventsarrow_forward
- Your biology lab instructor gives you a petri dish of agar covered with visible colonies. Your lab partner says the colonies are viruses, but you disagree. How do you know the colonies are bacteria?arrow_forwardWhen Wimmer and coworkers announced that they had synthesized the poliovirus, they created considerable controversy. Some people feared that deadly and highly contagious viruses might be synthesized by bioterrorists. The researchers responded that they were merely applying current knowledge and techniques to demonstrate the principle that viruses are basically chemical entities that can be synthesized in the laboratory. Do you think scientists should synthesize viruses or other agents that can cause infectious disease? What are the implications of forbidding such research?arrow_forwardAnswer the following regarding the varicella-zoster virus: a) the biology of the virus ( type: DNA/RNA type: single or double stranded) b) how it replicates c) life cycle of the virus (binding, fusion, reverse transcription, integration, replication, and assembly)arrow_forward
- Assume you isolate a single stranded (+) RNA virus. When you examine the proteins in the virus, you find that it does NOT contain replicase enzymes within its capsid. Which of the following is true? This virus must have a gene that encodes replicase. This virus will not be able to enter a host cell. Its genome cannot be translated (the process of translation) by the host cell ribosomes. A DNA copy of the viral genome has to be made before viral genes are expressed. This virus must lack surface antigens.arrow_forwardThe genome of which of the following types of animal virus can act directly as MRNA and be utilized by ribosomes without prior processing? O 1) retroviruses O 2) SSDNA viruses 3) -SSRNA viruses O 4) +SSRNA viruses 5) dsDNA virusesarrow_forwardViruses are host-specific, meaning they can only infect specific types of host organisms. For examble, the adenovirus is responsible for the common cold in humans but your dog can't catch a cold from you. Why is this? The proteins on the virus surface can only bind with proteins on the correct host surface. It is an enveloped or non-enveloped virus. The enzymes carried by the virus are compatible with the host. The genome of the virus is made of DNA or RNA.arrow_forward
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What Is A Virus ? ; Author: Peekaboo Kidz;https://www.youtube.com/watch?v=YS7vsBgWszI;License: Standard YouTube License, CC-BY