JFK History essays

JFK History essays John Fitzgerald Kennedy, was the 35th president of the United States. He was the youngest man and the first Roman Catholic ever elected to the presidency. Rich, handsome, elegant, and articulate, he aroused great admiration at home and abroad. His term of office as president was too short, however, to say what his place in history might have been Kennedy was born in Brookline, Massachusetts, on May 29, 1917. His father, Joseph P. Kennedy was a businessman who became a multimillionaire, head of the Securities and Exchange Commission, and ambassador to Great Britain. Kennedy graduated from Choate School in Wallingford, Connecticut. He then briefly attended Princeton University, and then entered Harvard University in 1936. At Harvard he wrote an honors thesis on British foreign policies in the 1930s. It was published in 1940, the year he graduated, under the title Why In 1941, shortly before the United States entered World War II, Kennedy joined the U.S. Navy. He attended a school to learn about the Patrol Torpedo boat. Kennedy was sent to the islands of the South Pacific Ocean where he was in charge of a Torpedo boat, everybody called him Skipper John Kennedy, the boat was called PT 109. The boat had been in battle and and it was dirty. The engines were in need of repair. J.F.K went to work, and soon the PT 109 was ready for war. J.F.K said, "the torpedos would sink any ship on the sea". Near an old pier the PT boats waited every day. When night came, they were ready for war. They drifted out into the ocean and listened for the sound of engines of enemy ships, for three or more nights they did that but they didn't find anything. One night in early autumm four enemy ships had been spotted near an island. The PT boats waited for dark so they wouldn't be seen. Slowly the PT 109 rode the black waves and every man of the crew listened. The crew could here the sou ...

Cartilaginous Fish - Chondrichthyes - Profile

Cartilaginous Fish - Chondrichthyes - Profile Cartilaginous fishes (Chondrichthyes) are a group of vertebrates that includes sharks, rays, skates and chimaeras. Members of this group include the largest and most formidable marine predators alive today such as the great white shark and the tiger shark as well as large filter feeders such as the manta ray, whale shark and basking shark. Cartilaginous fishes have a skeleton that consists  of cartilage (in contrast to their cousins the bony fish, whose skeletons are made up of true bone). Cartilage is both tough and flexible and it  provides sufficient  structural support to enable cartilaginous fishes to grow to considerable size. The largest living cartilaginous fish is the  whale shark  (about 30 feet long and 10 tons). The largest known cartilaginous fish ever to have lived is  Megalodon  (about 70 feet long and 50-100 tons). Other large cartilaginous fish include the manta ray (about 30 feet long) and the basking shark (about 40 feet long and 19 tons). Small cartilaginous fishes include the short-nose electric ray (about 4 inches long and weighs 1 pound), the starry skate (about 30 inches long), the pale catshark (about 8 inches long) and the dwarf lantern shark (about 7 inches long). Cartilaginous fishes is that they have jaws, paired fins, paired nostrils and a two-chambered heart. They also  have tough skin that is covered with small  tooth-like scales called denticles. Denticles are similar to teeth in many ways. The core of a denticle consists of a  pulp cavity that receives blood flow for nourishment. The pulp cavity is capped with a cone-shaped layer of dentine. The denticle sits on top of a basal plate which overlies the dermis. Each denticle is covered with an enamel-like substance. Most cartilaginous fishes live in marine habitats all their lives, but a few species of sharks and rays live in freshwater during all or part of their lives. Cartilaginous fishes are carnivorous and most species feed on live prey. There are some species that feed on the remains of dead animals and still others that are filter feeders. Cartilaginous fishes first appear in the fossil record about 420 million years ago during the Devonian Period.  The earliest known cartilaginous fishes were ancient sharks that were descended from bony-skeleton placoderms. These primitive sharks are older than the dinosaurs. They swam in the world’s oceans 420 million years ago, 200 million years before the first dinosaurs appeared on land. Fossil evidence for sharks is plentiful but consists mostly of tiny remnants of the former fish- teeth, scales, fin spines, bits of calcified vertebra, fragments of cranium. Extensive skeletal remains of sharks are missing- cartilage does not fossilize like true bone. By piecing together the shark remains that do exist, scientists have uncovered a diverse and deep ancestry. Sharks of the past include ancient creatures such as Cladoselache and Ctenacanths. These early sharks were followed by Stethacanthus and Falcatus, creatures that lived during the Carboniferous Period, in a window of time referred to as the â€Å"Golden Age of Sharks†, when shark diversity blossomed to include 45 families. During the Jurassic Period, there was Hybodus, Mcmurdodus, Paleospinax and eventually the Neoselachians. The Jurassic Period also saw the emergence of the first batoids: the skates and rays. Later came the filter feeding sharks and rays, the hammerhead sharks, and the lamnoid sharks (great white shark, megamouth shark, basking shark, sandtiger, and others). Classification Cartilaginous fishes are classified within the following taxonomic hierarchy: Animals Chordates Vertebrates Cartilaginous Fishes Cartilaginous fishes are divided into the following basic groups: Sharks, rays, and skates (Elasmobranchii) - There are about 800 species of sharks, rays, and skates alive today. Members of this group are known as elasmobranchs.Chimaeras (Chimaeriformes) - There are about 50 species of chimaeras alive today. Members of this group are also known as ghost sharks, spooksharks, or rabbit fish.