biology 1.1

• Living things consist of cells
• Living things


  Distinguishable from non-living things
• Characteristics of living things

  • Made up of one or more cells
  • Cells are the structural and functional units of living things
  • Cells come from pre-existing cells
  • Cells contain hereditary material
  • Cells are the smallest independent unit of life
• Cell membrane


  Defines a cell and separates it from its surroundings
• Cell types


  • Multicellular organisms
  • Red blood cells
• Biodiversity


  The vast diversity of living things that inhabit the planet
• Living thing


  Something that carries out fundamental life processes
• Fundamental life processes


  • Maintaining a stable internal environment
  • Controlled exchange of materials
  • Response to stimuli
  • Obtaining energy and chemical elements
  • Transport of materials
  • Removal of waste
  • Cell division
  • Growth and development
  • Independent movement
  • Reproduction
• Organism


  The name given to a living thing, can be unicellular or multicellular
• It has been estimated that there are about 37 trillion cells in an adult human being
• Cell


  The fundamental or basic unit of life, the unit of structure and function of organisms
• Endocrine disorders can result from abnormalities in the production, secretion, or action of hormones.
• Red blood cells
• Living things cost of cells
• Cells consist of large numbers of organelles
• Structures are not visible to the naked eye
• Different cell types including red blood cells, neurons only
• Cells are the building blocks of life
• The cell theory states that all organisms consist of cells or the products of cells, all cells come from pre-existing cells by the process of cell division, and cells are the building blocks of life
• Cells


  Membrane-enclosed organelles that have specific functions; e.g. a nucleus that controls the cell's activities
• Cells


  • Contain cytoplasm and some insoluble proteins
  • Found in animal and plant cells
• Unicellular organisms


  Living things that consist of one cell only
• Cells and DNA


  • Cells contain the chemical DNA (deoxyribonucleic acid) found in special coiled chromosomes
  • DNA enables cells to make important molecules like proteins for cellular function
  • DNA allows cells to divide and reproduce
• Heredity


  The passing on of characteristics genetically from one generation to the next
• Chromosomes


  • DNA is found in the nucleus of cells of multicellular organisms
  • DNA is a very long macromolecule associated with histone proteins
  • DNA can be packed into structures called chromosomes
• Cell membrane


  • A structure found in all cells that defines the cell and separates it from its surroundings
  • Controls the entry and exit of materials in and out of the cell
  • A thin layer 100nm thick consisting of two layers of phospholipid molecules with embedded proteins
• Fluid-mosaic model


  • Describes the structure and function of the cell membrane
  • Fluid: Lipids and proteins can move sideways in the membrane
  • Mosaic: Protein molecules are embedded in a pattern in the membrane
• Light microscope


  • An instrument used to produce a magnified image of a specimen
  • Can magnify up to 1500x
• Microscopes


  • Light microscope
  • Electron microscope
• Cell theory states that all living organisms are made up of cells and the products of cells, and that cells come from pre-existing cells
• Cells are the unit of structure and function in all living organisms
• Cells contain DNA which is the molecule of heredity
• All organisms are either unicellular or multicellular
• All cells have a cell membrane which defines them