The infinite variety: the beginning of life
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- Cnidarians and the Fossil Record
- BUILDING BODIES: INVERTEBRATES OF THE OCEANS Great Barrier Reef - Australia
Assignments IN YOUR OWN WORDS WRITE A ONE TO TWO PAGE ESSAY ON THE FOLLOWING TOPICS Discuss the structure and significance of DNA to life as we know it. Describe the process of fossilization and its significance in the interpretation of evolutionary events. Describe how cells have become specialized to perform different functions in a multicellular organism. Cnidarians and the Fossil Record Although Cnidarians are relatively simple organisms and appeared fairly early in the history of life, fossil evidence for them was only recently found (1940's) in the Flinders Range, southern Australia in rock strata that has been dated at about 650 million years. Not all Cnidarians are soft-bodied, and some produce skeletons of limestone in a similar way to the sea sponges and are better known as corals. These animals secrete their skeletons from their base. Each polyp is connected with its neighbours by strands that extend laterally. As the colony develops new polyps form, leaving a limestone skeleton that is riddled with tiny cells were polyps once existed. Live polyps are restricted to a thin surface layer. The size of these colonial polyps are enormous and create entire coral islands such as the Great Barrier Reef running parallel to the east coast of Australia. This coral reef extends for over a sixteen hundred kilometres and is the greatest animal construction prior to man's artifacts. Assignments IN YOUR OWN WORDS WRITE A ONE TO TWO PAGE ESSAY ON THE FOLLOWING TOPICS Discuss the structure and significance of DNA to life as we know it. Describe the process of fossilization and its significance in the interpretation of evolutionary events. Describe how cells have become specialized to perform different functions in a multicellular organism. BUILDING BODIES: INVERTEBRATES OF THE OCEANS Great Barrier Reef - Australia Living in association with the Great Barrier Reef is a multitude of higher animals which include shelled animals of the phylum Mollusca (clams, cowries, mussels and sea-snails), radially symmetrical creatures of the phylum Echinodermata and includes sea urchins and starfish, elongated animals with segmented bodies occurring in the phylums Annelida and Arthropoda which includes bristle worms, shrimps and crabs as well as the vertebrates (phylum Chordata) which includes cartilaginous and bony fishes and marine mammals such as dolphins and seals. 
The giant clam Tridacna gigas and a Parrot Fish. The Download 2.01 Mb. Share with your friends:
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