The Quaternary Period and Other Periods - 681 Words

Cambrian: †¢ This period started 540 million years ago and ended 500 million years ago. †¢ There was a very mild climate. The supercontinent Rodinia began to break into smaller parts, or continents. Lots of glaciation occurred so many animal families went extinct. †¢ All phyla develop during this time period. Many marine animals, shell-fish, echinoderms, and some of the earliest fish appear. †¢ Lots of glaciation occurred wiping out many animal families marking the end of the Cambrian period. Ordovician: †¢ This period started 505 million years ago and ended 438 million years ago. †¢ Many primitive plants appeared on land and some of the first corals. Primitive fish and fungi also make an appearance. High sea levels occur at fist but lower as global cooling, glaciation and volcanism increase. †¢ Plants, fungi and primitive fish are on land during this time period. †¢ Glaciation marked the end of the Ordovician period. Silurian: †¢ This period started 438 million years ago and ended 408 million years ago. †¢ The first vascular plants appear on land (plants with water-conducting tissue). High seas spread worldwide, brachiopods, crinoids and corals also make an appearance. †¢ The first fish with jaws appeared during this time period along with insects, centipedes and millipedes. †¢ Glaciation marked the end of the Silurian period. Devonian: †¢ This period started 410 million years ago and ended 360 million years ago. †¢ Swampy forests on land and fish and landShow MoreRelatedEssay On The Antibacterial Effects Of Microorganisms924 Words   |  4 PagesThe main for the purpose of this study was to find out about the tolerance of Listeria monocytogenes towards quaternary ammonium compounds (QAC). The antibacterial effects of disinfectants are crucial for the control of Listeria monocytogenes in food processing environments. Tolerance of L. monocytogenes to sub lethal levels of disinfectants based on QAC is conferred by the resistant determinants qacH and bcrABC. The QAC based disinfectants which are in common use in many food industries are foundRead MoreThe Effects Of Using Biological Evidence For Environmental Reconstruction Of The Climate During The Quaternary Period Essay2034 Words   |  9 Pagesevidence for environmental reconstruction of the climate in the Quaternary period. Introduction The Quaternary period refers to our current geological time period, it spans over two epochs, the Pleistocene and Holocene, during this geological period, the world has experience incredible climatic changes that have shaped the world we live in today. The Quaternary period has been characterised by numerous periods of glaciation, due to these periods of glaciation there were fluctuating changes in climate andRead MoreThe Appearance Of Homo Sapiens And The Disappearance Of Various Species Of Large Mammals1514 Words   |  7 Pagesdisappearance of various species of large mammals† –these words, I believe, demonstrate the theme of Paul S. Martin’s famed hypothesis. Martin’s theory, also known as the Overkill hypothesis, considers that humans were the sole contributors to the Late Quaternary extinction of megafauna that happened in the last 50,000 years in various continents, mainly in the Americas and Australia. According to Martin, as humans started coloniz ing new areas of the world, they introduced predators, competitors and diseaseRead MoreGlobal Warming: Human Activity vs. Natural Cycles1067 Words   |  5 Pagesto Heat Up Despite Clean Energy Efforts† that any prospect of reversing the continuing increase in the use of coal depended mostly in China, the world’s biggest energy consumer, which burns as much coal every year as the rest of the world combined. Other fossil fuels currently being used in the United States include natural gas, oil, petroleum, and liquefied petroleum gas (LPD). The cycle of the greenhouse effect begins when these greenhouse gases are emitted into the atmosphere. They then form a layerRead MoreBiochemistry of Proteins; Isolation of Ovalbumin and Enumeration of Thiol Groups1652 Words   |  7 Pagesestablish the number of thiol groups in Ovalbumin. This was done so by isolating and purifying ovalbumin protein from a standard egg-white preparation. This is useful in deducing the number of disul phide bonds it contains and therefore the tertiary/quaternary structure of the protein. Method A sample of ovalbumin was purified from an egg-white standard preparation and the number of thiol groups per protein molecule determined. This was achieved by precipitating the ovalbumin out of the egg-whiteRead MoreSummary and Critique1611 Words   |  4 PagesSouth America. Paul Martin of the University of Arizona and others see a subsequent and spontaneous connection between the presence of people and the vanishing of numerous species of large mammals. According to the overkill hypothesis, the spread of humanity correlates to the extinction of mammals at the same precise location they migrated to. The humans got to be big game hunters focusing on mammoths, giant bison, ground sloths, and other species of large size. They supposedly chased many speciesRead MoreGlobalization Healthcare1618 Words   |  7 PagesHealth Care Name: Institution: Healthcare ( (or human services) is the finding, treatment, and avoidance of malady, disease, harm, and other physical and mental weaknesses in individuals. Access to health awareness shifts crosswise over nations, gatherings, and people impacted by social and monetary conditions and, in addition, the wellbeing strategies set up. Nations and wards have distinctive policies and plans in connection with the individual and populace based socialRead MoreThe Issue Of Climate Change1321 Words   |  6 Pagesthat Milankovitch cycles control the pace of Quaternary ice ages... with the 100- [kilo year] eccentricity cycle dominant in early Quaternary...† and that Milankovitch cycles produce variations in the amount of solar radiation received by the earth and the latitudinal and seasonal distribution of this radiation... (12). These cycles act, as stated, on a very large time period and are near impossible to observe on human time scales, unlike some other natural influences to climat e. Unlike MilankovitchRead MoreEnzyme Catalysis Lab1186 Words   |  5 Pagesof methods for performing catalysis. Some provide a micro environment within the active site where some of the side chains are H+ or OH- donors or receivers. Other enzymes work by bringing together substrates that would not normally meet outside the enzyme, or orienting them in a manner in which they would otherwise not occur. Still other enzymes stress the bonds of substrate molecules in order to make them easier to break; some take this a step further by actually forming temporary covalentRead MoreBio Frq1509 Words   |  7 Pagesthe beta sheet, which in turn determines its secondary, tertiary, or quaternary structure. Another type of bonds, the covalent bond, links amino acids together by sharing electrons; this bond is critical to proteins in that it determines the amino acid sequence, and the primary structure of the peptide chain. Lastly, the ionic bond, it is a charged R group that determines whether the protein structure would be tertiary, or quaternary. (b) Discuss how the structure of a protein affects the function