The History of Life. Before You Read. Science Journal

Transcription

1 The History of Life Before You Read Use the What I Know column to list the things you know about the history of life. Then list the questions you have about the history of life in the What I Want to Find Out column. K W L What I Know What I Want to Find Out What I Learned Science Journal Think about early life on Earth. Describe the physical conditions that needed to be present in order for life to begin to form. The History of Life 141

2 The History of Life Section 14.1 Fossil Evidence of Change Skim Section 1 of the chapter. Write two questions that come to mind from reading the headings and the illustration captions Review extinction Use your book or dictionary to define extinction. New Cambrian explosion era fossil geologic time scale half-life K-T boundary law of superposition paleontologist period plate tectonics radiometric dating relative dating Use the terms in the left column to complete the paragraph below. Scientists measure Earth s geological and biological events using the, which is divided into and. The is the name of a period of rapid change during which the ancestors of most animal groups emerged. A layer of soot found between rock layers worldwide, known as the, might indicate that a large meteorite collided with Earth. The theory of describes Earth s surface as large plates that move over Earth s thick, liquid interior. These plates are made up of various types of rocks. are scientists who study. They determine the relative age of rocks using, which compares the sequence of rock layers. The states that younger rock layers are deposited on top of older rock layers. Another method of determining the age of rocks is, which measures the decay of radioactive isotopes. The rate of decay can be measured using, the amount of time required for half of a radioactive isotope to decay. 142 The History of Life

3 Section 14.1 Fossil Evidence of Change (continued) Earth s Early History Sequence the organizer below by listing the order of events that led to the formation of life in the oceans. The last step has been done for you. Volcanoes erupted, giving off gases and forming the early atmosphere. Clues in Rocks Identify three types of materials in which fossils are found Compare relative and radiometric dating using the table below. Provide three facts for each type of dating. Relative Dating Radiometric Dating The History of Life 143

4 Section 14.1 Fossil Evidence of Change (continued) The Geologic Time Scale Summarize the four eras of the geologic time scale using the table below. Geologic Era Major Biological Events Cambrian explosion at beginning of Paleozoic, mass extinction at end Organisms that Appeared unicellular life, eukaryotic cells, small marine animals dinosaurs, small mammals, flowering plants, birds Other Facts includes Earth s formation, almost 90% of Earth s entire history following extinction of dinosaurs, mammals diversify Rephrase the current theory on the cause of the mass extinction at the end of the Mesozoic era. SUMMARIZE Discuss how palentologists use relative and radiometric dating to support the geologic timescale. 144 The History of Life

5 The History of Life Section 14.2 The Origin of Life Scan Section 2 of the chapter. Use the checklist as a guide. Read all section titles. Read all boldfaced words. Look at all pictures and read the captions. Think about what you already know about the history of life. Write three facts you discovered about the origin of life Review amino acid New endosymbiont theory spontaneous generation theory of biogenesis Academic mechanism Use your book or dictionary to define amino acid. Use the term in a sentence to show its scientific meaning. Use your book or dictionary to define each term. Define mechanism to show its scientific meaning. The History of Life 145

6 Section 14.2 The Origin of Life (continued) Origins: Early Ideas Create a cartoon that illustrates how Redi s experiment was used to disprove spontaneous generation. Compare spontaneous generation and biogenesis. Spontaneous Both Biogenesis Origins: Modern Ideas Model Oparin s primordial soup hypothesis for the formation of simple organic molecules by filling in the graphic organizer below. started chemical reactions of gases in the early atmosphere Identify four requirements for life using the concept map below. Requirements for Life 146 The History of Life

7 Section 14.2 The Origin of Life (continued) Cellular Evolution Sequence how oxygen accumulated in the atmosphere and the effect it had on life by completing the flowchart below. little oxygen in atmosphere; all living things are anaerobic ozone layer forms Identify three properties that mitochondria and chloroplasts share with prokaryotes SUMMARIZE scientists. Analyze the endosymbiont theory of the evolution of plant cells by completing the sequence chart. bacteria evolved into mitochondria Analyze how the four requirements for life were identified by The History of Life 147

8 Tie It Together Write an analogy to explain the difference between radiometric and relative dating. Develop a second analogy to explain the endosymbiont theory. Analogy of dating methods used by palentologists: SUMMARIZE Analogy of endosymbiont theory: 148 The History of Life