<p> Name: ______Hr: ___ Viruses (19-2)</p><p>1. Label the picture below. Read the section “What is a Virus?” on page 478 to do this.</p><p>Head DNA Capsid</p><p>Tail Fibers Surface Proteins Membrane envelope</p><p>2. What is a virus made of? Core of DNA or RNA and a protein coat called a “capsid”; surface proteins</p><p>3. What does the word virus mean? “poison”</p><p>4. Viruses that infect bacteria are called __bacteriophages______.</p><p>5. Study the incorrect statements below. Change the underlined word(s) to make each sentence correct. Write the correct new word(s) on the line. a. Viruses are in the kingdom Archeabateria. _not alive or not in a kingdom_</p><p> b. Viruses are made of cells. _DNA/RNA and Capsid_</p><p> c. Viruses can be seen with a light microscope. _an electron_</p><p> d. Viruses can cause damage only in humans. _all kinds of organisms_</p><p> e. Each kind of virus infects several hosts. _certain types of hosts_</p><p> f. Viruses are always larger than the cells </p><p> they infect. __smaller___</p><p> g. Viruses reproduce outside of living cells. __inside______</p><p> h. Viruses do not harm the cells in which they live. __kill_____ 6. Using the section on lytic infection on page 480, put the following pictures in the correct order. Also, describe what is happening at each stage.</p><p>Order 4 1 5 2 3</p><p>1 virus attaches 2 virus 3 virus parts 4 virus 5 cell gets so What is itself to a injects its are made parts are full of viruses happening? specific cell DNA/RNA assembled it errupts</p><p>7. What is the difference between a lytic and lysogenic infection? Lytic: virus enters cell, makes copies of itself, and causes cell to burst Lysogenic: virus intergrates its DNA into the DNA of host cell, and viral genetic info replicates along with the host cell’s DNA. Lysogenic infection can stay inactive for a period of time and then enter the lytic stage (causing cell to burst)</p><p>8. Viruses are sometimes confusing to scientist because they show signs of acting both alive and not alive. List three things they have in common with living things (cells). a. Have a genetic code (DNA or RNA)</p><p> b. Change over time</p><p> c. Reproduce (but require a host cell)</p><p>9. List three reasons why scientists do not believe viruses are alive. a. no growth and development</p><p> b. don’t obtain and use energy</p><p> b. Don’t respond to environment</p><p>10. Read the section on Preventing Bacterial Disease, page 486. </p><p>Some bacterial and viral diseases can be prevented using a __vaccine______. </p><p>What type of infection are antibiotics used for? _bacterial only, viruses will not respond to antibiotics______</p>