Download ACADEMIC BIOLOGY: READING GUIDE for Ch

ACADEMIC BIOLOGY: READING GUIDE for Ch. 18, Section 1
Name:
18.1: VIRUSES
1. What are the two objectives of this section according to the section preview on pg 475?
2. Define the following words:
a. nucleic acid
b. virus
c. host cell
d. bacteriophage
e. capsid
f. lytic cycle
g. lysogenic cycle
h. provirus
i. retrovirus
j. reverse transcriptase
1
WHAT IS A VIRUS?
3. What are four reasons that viruses are considered to be non living? (pg. 475)
4. “Seven similar-looking viruses that infect the common intestinal bacteria, Escherichia coli, have the
code numbers _____ through _____. T stands for ________.” (pg. 475)
VIRAL STRUCTURE
5. After reading the 2 paragraphs in this section, describe in your own words 2 ways that all viruses
are alike and 2 ways that viruses may differ. (pg. 476).
ATTACHMENT TO A HOST CELL
6. Read the second paragraph in this section and explain in your own words how is the attachment of
a virus to its host cell like two pieces of a jigsaw puzzle fitting together? (pg. 476)
ATTACHMENT IS A SPECIFIC PROCESS
7. Most viruses are ‘species specific’ meaning they can only attach to a few kinds of cell. Which kind
of virus is easier to control, species specific viruses, or one that is not species specific? Describe the
evidence in this section to support your answer. (pg 477-478)
VIRAL REPLICATION CYCLES
8. Viruses have 2 ways of getting into a cell. The virus may inject its nucleic acid into the host cell, like
a _____________. An enveloped virus enters the host cell in a different way. After attachment, the
plasma membrane of the host cell _____________ the virus and produces a virus-filled
_____________. Then the virus bursts out of the vacuole and releases its _______________ ________
into the cell. (pg. 478)
LYTIC CYCLE
9. Read about the lytic cycle on page 479. In this type of viral replication, the host cell uses its own
_______________, ______ _________________, and ____________ to make copies of viral genes that
2
along with viral proteins are assembled into new viruses, which _________ from the host cell,
_____________ it.
LYSOGENIC CYCLE
10. The lysogenic cycle like the lytic cycle in the way it begins. The virus _______________ to the host
cell’s plasma membrane and its ___________ ______ enters the cell. (pg 479)
11. In your own words, explain how the lysogenic cycle is different from the lytic cycle (pg. 479):
DISEASE SYMPTOMS OF PROVIRUSES
12. What are 3 examples of disease-causing viruses that undergo the lysogenic cycle? (pg. 480)
RETROVIRUSES
13. The type of genetic material that a retrovirus, such as HIV has is _________? (page 481)
HIV: AN INFECTION OF WHITE BLOOD CELLS
14. After reading the first paragraph in this section, explain in your own words why an individual with
HIV can transmit the virus, even when not appearing sick? (page 482)
3