Practice Exam Guide (Peekskill)

• Index of Living Environment Units


  • Unit 1: Science and the Living Environment
  • Unit 2: Characteristics of Living Things
  • Unit 3: Homeostasis and the Human Body
  • Unit 4: Reproduction
  • Unit 5: Genetics
  • Unit 6: Evolution
  • Unit 7: Ecology
  • Appendix: State Labs
• Unit 1: Science and the Living Environment

  • Scientific method
  • Controlled experiments
  • Graphing
  • Characteristics of good experiment
• Unit 2: Characteristics of Living Things

  • Chemistry (carbohydrates, lipids, proteins, enzymes, acids and bases)
  • Homeostasis, metabolism, and life processes (including photosynthesis and respiration)
  • Cells
• Unit 3: Homeostasis and the Human Body


  • Organization
  • Human body systems
  • Diseases and disorders
• Unit 4: Reproduction


  • Mitosis and meiosis
  • Asexual and sexual reproduction
  • Human reproduction and development

  
• Unit 5: Genetics


  • Genetic code and protein synthesis
  • Genetic technology
• Unit 6: Evolution


  • Natural selection
  • Speciation
  • Gradualism vs Punctuated Equilibrium
  • Evidence for evolution
  • Classification
• Unit 7: Ecology


  • Interactions between organisms
  • Food chains and food webs
  • Biodiversity
  • Human impact on the environment
• Appendix: State Labs


  • Making Connections (Clothespin Lab)
  • Relationships and Biodiversity (Botana curus lab)
  • Beaks of Finches
  • Diffusion Through a Membrane
• The LE Exam consists of approximately 75 questions worth a total of 85 points. The exam is broken down into 4 parts:
• Parts of the LE Exam

  • Part A: General knowledge multiple choice questions (30 points)
  • Part B: A mix of multiple choice and short answer, dealing with the application of knowledge. So far, Part B has always required students to draw a line graph. (25 points)
  • Part C: Short answer questions dealing with your ability to apply material learned in the course to real world situations. (15 points)
  • Part D: Multiple choice and short answer, pertaining to the 4 NYS labs performed during the school year. (15 points)
• The state requires all answers to be recorded in such a way that they can not be tampered with. As such, all answers on the test must be written in permanent pen, and mistakes may not be "scribbled out."
• Observation


  What is seen or measured
• Inference


  A conclusion based on observation or evidence
• Hypothesis


  A prediction based on available evidence. A good hypothesis states both cause and effect.
• A correct hypothesis can be tested and falsified (proven incorrect) using an experiment.
• Theory


  An explanation of natural events that is supported by strong evidence
• Theories tie together many scientific facts, hypotheses and laws.
• Misconception: "Theories are things that are opinions, or are not proven." This is an incorrect use of the word "theory" in a scientific context. A scientific theory is not a simple guess or conjecture, and is strongly supported by evidence.
• Controlled Experiment


  Compares the results of an experiment between two (or more) groups
• Experimental group


  Group being tested or receiving treatment
• Control group


  "Normal" group. Should be identical to experimental group in every way except one: it does not receive the new treatment
• Placebo


  A sugar pill or other "fake" treatment given to the control group
• Independent Variable


  Variable that is being tested (ex: new drug, new fertilizer)
• The independent variable is always plotted on the X axis.
• Dependent Variable


  Variable that is measured at the end of an experiment; the results
• The dependent variable is always plotted on the Y axis.
• Data tables


  • Used to organize data which will be plotted in a graph
  • First column is for the independent variable
  • Second column is for the dependent variable
  • Each column should be titled, and include units of measurement
  • Data must be arranged in ascending or descending order
• Graphs


  • Both the x and y axis must be labeled or titled, including units of measurement
  • The independent variable is always plotted on the x-axis
  • The dependent variable is always plotted on the y-axis
  • The x and y axis must be numbered, increasing by a uniform increment
  • All graphs drawn on the LE Regents have been line graphs
  • All points plotted must be surrounded by a circle (or sometimes a square or triangle)
• Characteristics of a good experiment

  • Can be repeated the same way and get the same results
  • Have large sample size/many test subjects
  • Are performed for longer periods of time
  • Test only one independent variable. All other characteristics of the tested groups should be the same
  • Are peer reviewed – examined by several scientists to determine its accuracy
  • Must test the hypothesis and show whether it is wrong or right
  • Is objective – the experiment and conclusion are fair and unbiased. Fact and opinion are not mixed
  • Follows established ethical and legal standards
• The most common elements in living things are (in order) Carbon, Hydrogen, Oxygen and Nitrogen (CHON).
• Organic Compounds


  Have Carbon AND Hydrogen
• Organic molecules are larger than inorganic molecules.
• Carbohydrates


  Sugars and starches that supply energy
• Enzymes may break down starches and complex sugars into simple sugars.
• Lipids


  Store energy and include fats, oils and waxes
• Proteins


  Made from amino acids. Proteins make most of the chemicals used to build and run an organism's body.
• It is the SHAPE of proteins and how they fit together with other molecules that determines what proteins can do.
• Four specific jobs of proteins

  • Enzymes
  • Receptor molecules on the cell membrane
  • Antibodies
  • Hormones
• Enzymes


  Catalysts made from protein that affect the rates (speed) of chemical reactions