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Published byAubrey Stanley Modified over 9 years ago
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Biology…What is it? Biology is the study of life. SO….What does it mean to be living?
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Characteristics of Life To be considered living, an organism must….. 1. Be based on a universal genetic code. –DNA 2. Grow and develop
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Characteristics of Life 4. Nutrition: To obtain materials to use for building blocks and energy. 3. Be able to R eproduce -Asexually -Sexually
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5.Excretion: Producing and releasing waste materials. 5.Metabolism: all chemical reactions. -Digestion and synthesis Characteristics of Life
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7. Be able to sense and respond to their environment -stimulusresponse Humans: Plants:
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Characteristics of Life 8. Maintain stable internal environment -Homeostasis
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Characteristics of Life 9. Change over time, as a group. -Evolution 10. Made of units called Cells -Unicellular -Multicellular
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Levels of Organization LevelFunctionExample OrganismSingle living thing Organ SystemDifferent organs function together OrganDifferent tissues function together TissuesSimilar cells function together CellsSmallest unit of life Molecules Smallest unit of a substance with the same properties AtomSmallest unit of matter Nervous System Brain Nervous Tissue Nerve Cell Protein Carbon Human
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Viruses…Living or not? Now that we know what makes something living, let’s look at a virus. Viruses come in many different shapes and they cause many different diseases but, they all have something in common….
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Viruses and Living Cells CharacteristicVirusCell StructureGenetic material surrounded by a protein capsid Cell membrane, cytoplasm; genetic material, ribosomes ReproductionOnly within a host cellYes, sexually and asexually Genetic CodeDNA or RNADNA Growth and Development NoYes MetabolismNoYes Sense and Respond NoYes EvolveYes HomeostasisNoYes
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Life Cycle of a virus Lytic Cycle
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Life Cycle of a virus Lysogenic cycle
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What about viruses? https://www.youtube.com/watch?v =PHp6iYDi9ko https://www.youtube.com/watch?v =Rpj0emEGShQ
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