CELLS The Building Blocks of Life What is a Cell? Small units that carry out all of an organisms life activities. Plant, Animal and Bacterial Cells Eukaryotic plant & animal Nucleus (protects DNA) Prokaryotic bacteria No nucleus (DNA floating inside cell) Eukaryotic (plant & animal cells) Prokaryotic (bacterial cells) Cytology The branch of life science, which deals with the study of cells in terms of structure, function and chemistry. Cytopathology: the study of cellular disease and the use of cellular changes for the diagnosis of disease. Cell Biology: the study of (normal) cellular anatomy, function and chemistry. Important Contributions Hooke Leeuwenhoek Virchow Schleiden Schwann Who Did What? Robert Hooke Anton van Leeuwenhoek Mathias Schleiden Theodor Schwann Rudolph Virchow Discovered cells when he looked at cork. Discovered bacteria and protists. Studied plants and plant cells. Studied animals and animal cells. Discovered that living cells only come from other living cells. The Cell Theory All organisms are composed of one or more CELLS. The cell is the basic unit of LIFE in all living things. All cells come from EXISTING cells. Cells... The Building Blocks of Life. Levels of Biological Organization The Cell Bacteria Somatic Cells Skin Bone Muscle Red blood White blood Cheek Leaf Sex Cells Egg Sperm The Cell Unicellular Made of a single cell. Multicellular Made of many cells. Organelles Tiny Organs Structures within a cell that help it live, grow and reproduce. All cells have a cell membrane, cytoplasm and DNA (nuclear material). Tissues & Organs Tissues Several cells working together. Cells working in teams. Ex. muscle, nerve xylem, phloem Organs Several tissues working together. Ex. stomach, heart, leaf, roots, stem Organ Systems & Organisms Organ Systems Organs working together. Ex. digestive, respiratory, nervous, excretory, cardiovascular, leaf & root system Organisms Independent living; any living thing. Ex. animal, plant, fungi, protists, bacteria Think Big... Population Community Ecosystem Biome Biosphere Organisms of the same kind living in the same area; deer in a forest, fungi growing on a rotting log. Two or more populations living in the same area; foxes, oak trees, lizards & flowers in a forest. Communities of living organisms and abiotic factors in an area; rivers, lakes, small forests, prairies, your own backyard. Ecosystems co-existing in a large geographical area; deciduous forest, tundra, desert, marine. The Earth and surrounding atmosphere supporting all life.