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Ch 3, Sec 1 Discovering Cells Cells - basic units of structure & function in living things - form the parts of an organism & carry out all organisms processes - structure - structure of living things determined by the way cells are put together - function
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Ch 3, Sec 1 Discovering Cells Cells - basic units of structure & function in living things - form the parts of an organism & carry out all organisms processes - structure - structure of living things determined by the way cells are put together - function - cells are involved in functions of getting food & oxygen, ridding of waste, & growing
- size - super small, measured in micrometers (μm) - only visible with microscope - 1 cm2 of skin has >100,000 cells First Observation of Cells - didn’t happen until late 1600’s, after invention of microscope - Robert Hooke (1663) - one of the first to see cells after he built own compound microscope (2 lenses, single view) - looking at cork, noted tiny rectangular rooms, called them “cells” (small rooms)
- Anton van Leeuwenhoek (1674) - built a simple microscope (1 lense) - noted tiny organisms moving in water - called them “animalcules” (little animals) Development of Cell Theory (these 3 scientists) - Matthias Schleiden (1838) - stated that all plants were made of cells - Theodor Schwann (1839) - stated that all animals were made of cells - Rudolf Virchow (1855) - stated that all cells come from cells
- Cell Theory - widely accepted explanation of the relationship between cells & living things 1. All living things are composed of cells 2. Cells are the basic units of structure & function in living things 3. All cells are produced from other cells Unicellular - single celled organism (bacteria) Multicellular - organism composed of many cells
Organization of cells (Important!!!) - cell - tissue - group of SIMILAR cells working together to perform specific functions (ex: nervous tissue in brain made of nerve cells) - organ - group of different tissues that work together (ex: brain) - organ system - group of organs that work together to perform major functions (ex: nervous system)