Essay about Reading guide chapter 19

662 WordsJan 25, 20153 Pages
AP Biology Name Allison Werts Period 2 Chapter 19 guided Reading Assignment 1. What kind of nucleic acids are the viral genomes made of? A singular linear or circular molecule. 2. What is the name for a protein shell enclosing the viral genome? The name of the protein shell that encloses the viral genome is a capsid. 3. What are viral envelopes and what is their function? They are membranes that cloak the capsid that in turn encloses a viral genome. 4. Define host range. It is the limited range of host cells that each type of virus can infect and parasite. 5. List the full steps of the simplified viral reproductive cycle. 1.) Virus enters cell and is uncoated, releasing viral DNA and capsid proteins 2.) Host enzymes replicate the…show more content…
15. Describe the reproductive cycle of HIV, a retrovirus. The virus fuses with the cell’s plasma membrane. The capsid proteins are removed, releasing the viral proteins and RNA. Reverse transcriptase catalyzes the synthesis of a DNA strand complementary to the viral RNA. Reverse transcriptase catalyzes the synthesis of a second DNA strand complementary to the first. The double-stranded DNA is incorporated as a provirus into the cell’s DNA. Proviral genes are transcribed into RNA molecules, which serve as genomes for the next viral generation and as mRNAs for translation into viral proteins. The viral proteins include capsid proteins and reverse transcriptase (made in the cytosol) and envelope glycoproteins (made in the ER). Vesicles transport the glycoproteins from the ER to the cell’s plasma membrane. Capsids are assembled around viral genomes and reverse transcriptase molecules. New viruses bud off from the host cell. 16. What are vaccines? They are harmless variant or derivative of a pathogen that stimulates a host’s immune system to mount defenses against the pathogen 17. What are the three processes that contribute to the emergence of viral diseases? The mutation of existing viruses, the spread of existing viruses from one host species to another, and the dissemination of a viral disease from a small, isolated population that can lead to widespread epidemics. 18. List and explain the two major routes
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