exam 1

• What are the 7 characteristics of life?

  1. Homeostasis
  2. Organization
  3. unicellular vs multicellular
  4. Living things are made of units - cells
  5. Metabolism
  6. breaking down large molecules into ATP (energy)
  7. Growth and development
  8. growth = unicellular
  9. development = multicellular
  10. Adaptation
  11. Living things have the capacity to evolve
  12. Responses to stimuli
  13. stimulus: a signal to which an organism responds
  14. Reproduction
  15. asexual vs. sexual
  16. Universal genetic code
  17. genetic code is basically the same for all organisms on Earth
  18. Cytosine, Adenine, Thymine, Gaunine
• describe the major structural levels of organization of the human body.

  subatomic particles (chemical) --> atom (chemical) --> molecule (chemical) --> macromolecule (chemical) --> cell --> tissue --> organ --> organ system --> organism
• muscle tissue - movement

  nervous tissue - signal

  connective tissue - support

  epithelial tissue - cover
• two or more tissues make up an organ and two or more organs make up an organ system
• integumentary system: skin, hair, and nails protect underlying tissue
• muscular system: skeletal muscles move your bones
• cardiovascular system: heart pumps blood through all your blood vessels
• urinary system: removes wastes from the blood and regulates the body's fluids
• respiratory system: lungs absorb oxygen and release carbon dioxide
• nervous system: receives and sends electrical messages throughout body
• lymphatic system: returns leaked fluids to blood vessels and get rid of germs
• digestive system: breaks down the food you eat into nutrients that can be absorbed into your body
• endocrine system: glands regulate body functions by sending out chemical messengers. The ovaries, in females, and testes, in males, are part of this system
• homeostasis: the process where the body keeps internal conditions relatively constant despite changes in external conditions
• physiological variables for homeostasis:

  1. temperature
  2. pH
  3. blood glucose
  4. osmotic balance
  5. blood O2/CO2
  6. calcium
• sensor: detects changes and sends signals to control center
• control center: sets the range of values within which a variable should be maintained, sends signals to to effector
• effectors: responds to signals from a control center to effect change in a variable
• negative feedback loops: return back to "normal" range
• positive feedback loops: increase/reinforce initial stimulus
• How are structure and function related?


  form of structure follows function at all levels of organization; form follows function
• gradient: present any time more of something exists in one area than another, where two areas are connected
• gradients drive many physiological processes
• cells in body must work together to maintain homeostasis of entire organism via chemical messengers or electrical signals
• atomic number: number of protons
• mass number= # of protons + # of neutrons
• # protons = # electrons
• electron shells: regions surrounding atomic nucleus where electrons exist
• element: simplest form of matter to have unique chemical properties
• atoms: consist of protons, neutrons, electrons
• 4 major elements found in the body:

  1. hydrogen
  2. nitrogen
  3. oxygen
  4. carbon
• isotopes: atoms that differ only in different # of neutrons
• radioisotopes: an isotope in nature that are very unstable and contain high levels of nuclear energy that form nuclear radiation and undergo radioactive decay
• nuclear medicine:

  1. cancer radiation therapy
  2. radiotracers: injections into patient; detected by camera; image analyzed by computer; shows size, shape and activity of organs and cells
  3. treatment of thyroid disorders: high doses of iodine-131 treat overactive or cancerous thyroid tissue
• solutions: mixtures of liquids, gases, or solids; evenly distributed particles

  • solute: substance dissolved
  • solvent: substance that dissolves solute
• suspension: unevenly distributed particles; will settle out when left undisturbed
• if octet rule is not satisfied the atom is reactive
• if octet rule is satisfied the atom is inert
• valence electrons: electrons in the outermost shell that is used for chemical bonding
• duet rule: atom is most stable when valence electron shell holds 2 electrons