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Chapter 8: Life’s structure and Classification. Living Things. What are living things like?. Organism: Any living thing Can vary in size (bacteria---gigantic oak tree----humans) Have different behaviors and food requirements. Similarities between all living things. They are organized
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Chapter 8: Life’s structure and Classification Living Things
What are living things like? • Organism: Any living thing • Can vary in size (bacteria---gigantic oak tree----humans) • Have different behaviors and food requirements
Similarities between all living things • They are organized • All organisms are made up of cells (the smallest unit of an organism that carries on the function of life) • They grow and develop • Infant—adult • Organisms change as they grow (development) • They respond • Living things must interact with their environment • Stimulus: Anything that causes some change in an organism. • Response: the reaction to a stimulus-Results in movement
Similarities between all living things (continued..) • They maintain homeostasis • Ability of an organism to maintain proper internal conditions despite changes in the environment. • They use energy • All organisms require energy for everyday life functions (staying organized, carrying on activities-finding/making food) • They reproduce • Making their own kind • Living things need to replace those individuals that die
What do living things need? • A place to live • Suited to their unique needs (temperature, sunlight, space etc..) • Water • Important functions: transporting materials within a cell and between cells. • We are made up of 60-70% of water! • Food sources • Take in substances (protein, fats, sugars) from other animals • Plants and some bacteria make their own food
Cell Structure What are cells? What are the functions of each part of a cell? - What is the difference between unicellular and multi-cellular organisms?
A little history • 1600’s : Leeuwenhoek made a simple microscopeled to types of microscopes we use today • Discovered cells under microscope • Robert Hooke looked at a cork and saw many empty little boxes—named them cells • 1800’s: Schleiden(plant cell) and Schwann (animal cell): all living things are made up of cells • Virchow: main contributor to the cell theory
The Cell Theory • All organisms are made up of one or more cell • The cell is the basic unit of organization in organisms • Basic unit of structure and function • All cells come from cells • Divide to form new, identical cells
Prokaryotic: only found in ONE-celled organisms Cells without membrane-bound structures Ex: Bacteria Eukaryotic: More complex internal structure Cells with membrane bound structures Ex: protists, fungi, plants and animals Prokaryotic vs Eukaryotic Cell
Cellular organization - Main structures Organelle: parts of the cell
Cell structure Description/function • Cell Membrane • Protective layer surrounding every cell • Regulates interactions (what goes in and out) between the cell and its environment • Nutrients move in, waste moves out • Cytoplasm • Gelatin like substance which cells are filled with • Where the cells organelles are located • Most of cells life processes occur here • Nucleus • contains a membrane, nucleolus, and hereditary material (DNA) • Control center(all cellular activities are directed here)
Image Bank Eukaryotic Cell Membrane
Cell structure Description/function continued • Mitochondria • Powerhouse of the cell-releases energy that is needed by the cell • Golgi bodies • Stacked flattened membranes • Package material for release to the outside of the cell • Vacuole • Membrane-bound spaces • Temporary storage of materials (stores water, waste products, food etc.)
Cell structure Description/function continued • Endoplasmic reticulum (ER) • Series of folded membranes • Transport materials inside cell • Ribosomes • Make proteinsProteins: part of cell membranes and needed for chemical reactions that take place in the cytoplasm • Chloroplasts (plant only) • Contains chlorophyllUse light to make sugar-food and energy for plants
Cell structure/function • Lysosome • Break down & Recycle! • Contain digestive chemicals that break down food molecules, cell wastes, worn out cell parts and viruses and bacteria that enter cell • When cell dies, release chemicals to breakdown cell contents
Unicellular vs Multicellular organisms • Unicellular organism: • one celled organism (perform all life functions on their own) • Multicellular organisms: • many celled organisms (cells cannot function alone) • Celltissueorganorgan systemsorganism
Image Bank Many-Celled Organism