Do Not Destroy!

1. Learning how the smallpox virus evades the human immune system will provide clues on how to combat HIV. Both Variola and HIV seem to infect only humans, and in many cases they defeat the human immune system.

2. Knowing the DNA sequence of a virus is not sufficient to understand how it causes symptoms and evades the immune system.

3. Viral infections reemerge. Should a new virus evolve to fit the niche that Variola occupied, or an existing virus (such as monkeypox) expand and change to affect humans, the lack of supplies of smallpox virus could hamper research.

4. Smallpox could reappear even if we destroy the frozen samples. Variola may have been stored in other laboratories, and smallpox victims buried in Soviet permafrost could some day thaw and release active virus.

A final note is more philosophical. Even though a virus is not technically alive, do we have the right to destroy it? In the words of one researcher, "It's taken millions of years for nature to make the Variola virus, and why should 10 guys sitting around a table say: 'Let's destroy it'?"

Discussion

1. What is smallpox?

2. When did mankind free itself from the scourge?

3. Is it safe to store a virus like that in laboratories?

4. What is your answer to the question: “Should we destroy the last smallpox virus?”?

VI. Solve the following crossword puzzle using the clues below

Across:

1 a kingdom of unicellular, colonial, or multicellular organisms usually including the protozoans and most algae; 3 a preparation of killed microorganisms, living attenuated organisms, or living fully virulent organisms that is administered to produce or artificially increase immunity to a particular disease; 4 a kingdom of prokaryotic unicellular round, spiral, or rod-shaped single-celled microorganisms that are often aggregated into colonies or motile by means of flagella, that live in soil, water, organic matter, or the bodies of plants and animals; 6 a category of taxonomic classification ranking above the family and below the class; 9 a category of biological classification ranking between the family and the species, comprising structurally or phylogenetically related species; 12 a major category in biological taxonomy ranking above the order and below the phylum or division; 13 a group that constitutes one of the usually primary divisions of the animal kingdom; 14 an organism that lives in the absence of free oxygen; 15 an organism capable of performing life functions only in the presence of oxygen; 16 a group of related plants or animals forming a category ranking above a genus and below an order and usually comprising several to many genera; 17 a category of biological classification ranking immediately below the genus or subgenus, comprising related organisms or populations potentially capable of interbreeding.

Down:

1 a protein particle that lacks nucleic acid and is believed to be the cause of various infectious diseases of the nervous system; 2 an organism living together with another dissimilar organism in a mutually beneficial relationship; 3 a complete virus particle that consists of an RNA or DNA core with a protein coat sometimes with external envelopes and that is the extracellular infective form of a virus; 5 any of a major group of saprophytic and parasitic spore-producing organisms usually classified as plants that lack chlorophyll and include molds, rusts, mildews, smuts, mushrooms, and yeasts; 7 an organism living in, with, or on another organism and obtaining benefits from the host which it usually injures; 8 the DNA-containing area of a prokaryotic cell; 10 an organism living on dead or decaying organic matter; 11 any of various enzymes that promote hydrolysis of nucleic acids.

1					2				3
					4
			5
									6						7
8			9				10
											11
12							13
		14
										15
		16
		17