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Grade 7
Life Science
Unit 2 REVIEW packet answer key
Life Processes
  1. Find sunlight, shelter, find a mate, find food and water, Escape danger (predators, etc.)
  2. Stimulus (something which an organism must respond to)
  3. Increase size or make more cells, develop, become more complex
  4. Metabolism- breaking down materials into usable energy
    1. Ingest – take in food and water
    2. Digest – break down food
    3. Respire – to use energy from food
    4. Excrete – removal of waste
Chemistry of Living Things
  1. Matter – anything that takes up space and has mass, the “stuff” that makes up everything
  2. water transports materials in all organisms, is a part of the photosynthesis reaction, most chemical reactions occur in water, makes up about 70% of human body
    1. Carbohydrates  – gives organisms energy
    2. Lipids – gives energy to organisms when there’s no carbohydrates available
    3. Proteins – repairs, builds cells
    4. Nucleic Acids – copies stores and delivers genetic information
    1. Electron (negative charge)
    2. Proton (positive charge)
    3. Neutron (no charge or neutral charge)

  1.  Simple (magnifying glass)  uses one lens at a time
           Compound- uses more than one lens at a time
  1. You multiply the eyepiece magnification by the objective lens magnification= 400X
  1. As magnification increases the field of view decreases and the amount of detail increases.  As magnification decreases the field of view increases and the amount of detail decreases
           13 a.  Eyepiece                          j. diaphragm
           b. Body tube                         k. light or mirror
           c. Coarse adjustment knob
           d.    Arm
           e. Fine adjustment knob
           L. base
           f. Revolving nose piece
  1. Objective lenses
  2. Stage clips
  3. Stage
Cell Structures
  1. Chloroplast, mitochondria, nucleus, vacuole, chromosomes
15. Animal cells have centrioles, plants do not
Animal cells have lysosomes, plants rarely do
Plant cells have cell walls while animal cells do not
Plants have chloroplasts, animals do not
Plants have a larger vacuole
Plant cells are more box-like, animal cells are more round-ish
Cell Processes:
  1. Passive transport- diffusion of molecules not using energy
Diffusion- spreading of molecules from high concentration to low concentration,
Osmosis- diffusion of water across a semi-permeable membrane
  1. Active Transport- the movement of materials across a membrane with the use of energy
  1.  Respiration:
C6H12O6 + 6O2 => 6CO2 + 6H2O + energy (ATP)
  1. Interphase – organelles duplicate, DNA is copied, chromosomes duplicate, centrioles appear
Prophase – Nuclear membrane disappears – chromosomes appear
Metaphase – Chromosomes line-up in the middle
Anaphase – Chromosomes pull apart
Telophase – Cytoplasm starts to pinch, chromosomes are at opposite ends, nuclear membrane reappears
End result - identical daughter cells
  1.  Diffusion across a membrane:
    1. has to be dissolved
    2. has to be a difference in concentration – high area to low area movement of substance
  2.  small diagram:
    1. into the cell
    2. into the cell
    3. won’t move (it is not dissolved)
    4. out of the cell
    5. active transport
  1. will move into the cell
  2. will move out of the cell




Kenneth G. Slentz, Superintendent
45 East Elizabeth Street
Skaneateles, NY 13152
Phone: 315-291-2221

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