20 1 Worksheet Bell
Name Class Date
20.1 Viruses
Lesson Objectives
Explain how viruses reproduce.
Explain how viruses cause infection.
The Discovery of Viruses
1. What is a bacteriophage? Kind of virus that infects bacteria.
2. What are viruses? Particle made of proteins, nucleic acid and sometimes lipids that can only replicate by infecting other cells.
3. What is a capsid?
Protein coat surrounding a virus
4. How does a typical virus get inside a cell? Capside proteins
5. What occurs when viruses get inside cells?
Virus genes are expressed
6. Identify the parts of the virus as seen in the picture below.
A. B. C.
Viral Infections
7. VISUAL
In the visual analogy, why is the outlaw locking up the sheriff, instead of the other wa
The diagram below shows the lytic cycle of a viral infection. Label the bacterial DNA, host bacterium, viral DNA, and virus. Then, circle the step that shows lysis of the host cell.
9. In a lysogenic infection, how can one virus infect many cells?
It inserts itself into the hosts dna
10. How is the common cold like the HIV virus?
11. Why are viruses considered NONLIVING? Give at least 2 examples. Refer to the learning module for this.
12. What are the steps of the lytic cycle?
13. What are the steps of the lysogenic cycle?
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
Figure 20–4
____ 1. In Figure 20–4, the structure labeled D is called a tail fiber. _________________________
____ 2. In Figure 20–4, the structure labeled C is protein. _________________________
Completion
Complete each statement.
3. Every virus is a nonliving particle made up of ____________________ and ____________________.
Figure 20–4
4. In Figure 20–4, the structure labeled B is a(an) ____________________.
20.1 Viruses
Lesson Objectives
Explain how viruses reproduce.
Explain how viruses cause infection.
The Discovery of Viruses
1. What is a bacteriophage? Kind of virus that infects bacteria.
2. What are viruses? Particle made of proteins, nucleic acid and sometimes lipids that can only replicate by infecting other cells.
3. What is a capsid?
Protein coat surrounding a virus
4. How does a typical virus get inside a cell? Capside proteins
5. What occurs when viruses get inside cells?
Virus genes are expressed
6. Identify the parts of the virus as seen in the picture below.
A. B. C.
Viral Infections
7. VISUAL
In the visual analogy, why is the outlaw locking up the sheriff, instead of the other wa
The diagram below shows the lytic cycle of a viral infection. Label the bacterial DNA, host bacterium, viral DNA, and virus. Then, circle the step that shows lysis of the host cell.
9. In a lysogenic infection, how can one virus infect many cells?
It inserts itself into the hosts dna
10. How is the common cold like the HIV virus?
11. Why are viruses considered NONLIVING? Give at least 2 examples. Refer to the learning module for this.
12. What are the steps of the lytic cycle?
13. What are the steps of the lysogenic cycle?
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
Figure 20–4
____ 1. In Figure 20–4, the structure labeled D is called a tail fiber. _________________________
____ 2. In Figure 20–4, the structure labeled C is protein. _________________________
Completion
Complete each statement.
3. Every virus is a nonliving particle made up of ____________________ and ____________________.
Figure 20–4
4. In Figure 20–4, the structure labeled B is a(an) ____________________.