<span>The influenza pandemic of 1918-1919 killed more people
than the Great War, known today as World War I (WWI), at somewhere between
20 and
40 million people. It has been cited as the most devastating epidemic in
recorded world history. More people
died of influenza in a single year than in four-years of the Black Death
Bubonic Plague from 1347 to 1351. Known as "Spanish Flu" or "La
Grippe" the influenza of 1918-1919 was a global disaster. </span>
Answer:
Bacteria cells have no nucleus.
Answer:
False
Explanation:
Eukaryotes include animal cells which do not have chloroplasts
Group IV of the Periodic Table of the Elements contains carbon (C), silicon (Si) and several heavy metals. Carbon, of course, is the building block of life as we know it. So is it possible that a planet exists in some other solar system where silicon substitutes for carbon? Several science fiction stories feature silicon-based life-forms--sentient crystals, gruesome golden grains of sand and even a creature whose spoor or scat was bricks of silica left behind. The novellas are good reading, but there are a few problems with the chemistry.
<span>
CRYSTALLINE CREATURES? Silicon can grow into a number of lifelike structures, but its chemistry makes it unlikely that it could be the basis for alien life-forms.</span>
Indeed, carbon and silicon share many characteristics. Each has a so-called valence of four--meaning that individual atoms make four bonds with other elements in forming chemical compounds. Each element bonds to oxygen. Each forms long chains, called polymers, in which it alternates with oxygen. In the simplest case, carbon yields a polymer called poly-acetal, a plastic used in synthetic fibers and equipment. Silicon yields polymeric silicones, which we use to waterproof cloth or lubricate metal and plastic parts.
