1010 1

• Biology is


  the scientific study of life.
• Cells are


  the basic units of life.
• Every organism, or living individual, consists of

  one or more cells
• Cells use DNA to

  produce proteins.
• All life shares five characteristics:

  Organization

  Energy use

  Maintenance of internal constancy (Homeostasis)

  Reproduction, growth, and development

  Evolution
• An atom is


  The smallest chemical

  unit of a type of pure

  substance (element) and the smallest portion of an element
• ORGANISM is


  A single living individual.

  Example: One acacia tree
• Homeostasis is


  the process by which a cell or organism maintains equilibrium. Example: Thermostat
• Reproduction is either


  asexual or sexual
• Offspring of asexually reproducing organisms are

  identical to their single parent. Example Strawberry Plants
• Offspring of sexually reproducing organisms receive


  genetic material from two parents.
• Three Domains of Life

  Archaea, Bacteria, Eukarya
• Taxonomy


  The biological science of naming and classifying organisms.
• Domain Bacteria and Domain Archaea are

  prokaryotic and unicellular.
• Organisms in Domain Eukarya have

  cells with nuclei.
• Matter is


  any material that takes up space
• Elements are


  Substances that cannot be broken down into other substances
• Bulk Elements are


  elements which make up the majority of cells (C,H,O,N, +)
• Trace Elements are


  elements required in small amounts (Fe, ZN)
• Protons are


  positively charged particles; located in nucleus (center) of the atom
• Neutrons are


  uncharged particles; located in the nucleus of the atom
• Electrons are


  negatively charged particles; located in energy levels outside nucleus
• Atomic Number is the

  number of protons in nucleus
• In a neutral atom the # of electrons ______ the # of protons

  equal
• How many electrons can all three energy shells hold?

  1st (closest) can hold 2 electrons

  2nd can hold 8 electrons

  3rd can hold 8 electrons

  =18
• The Valence shell is


  an atom's outer-most energy shell
• A Molecule is


  two or more atoms covalently bonded together
• A Compound is


  two or more elemental materials united in a definite ratio
• Electronegativity is


  an atom's ability to attract electrons
• An Ion is


  charged atoms; have unequal numbers of electrons and protons
• An Isotope is


  atom with same number of protons but different number of neutrons
• A Covalent Bond is

  2 or more atoms share pairs of electrons to form molecules
• An Ionic Bond is

  attraction between oppositely charged ions
• Polarity is


  partial charges on molecules due to unequal sharing of electrons
• A Polar Covalent Bond is when


  atoms share electrons unequally
• A Hydrogen Bond is what

  forms when partial positive regions of one polar molecule are attracted to the partial negative regions of another polar molecule
• The 7 Properties of Water:

  cohesion

  adhesion

  high surface tension

  resists temperature change

  water expands when frozen - solid (ice) less dense than liquid

  evaporative cooling

  solvent for many molecules, atoms, and ions
• Cohesion is


  the sticking together of particles of the same substance.
• Adhesion


  the action or process of adhering to a surface or object.
• Solvent


  able to dissolve other substances.