Laboratory Experiment Rapid Review for AP Biology

By — McGraw-Hill Professional
Updated on Oct 24, 2011

For a more thorough review of the laboratory experiments below, refer to these concepts:

Experiments 1–12 are summarized.

Experiment 1: diffusion and osmosis

  • Water flows from hypotonic (low solute) to hypertonic (high solute).
  • To measure diffusion and osmosis, take dialysis bags containing solutes of varying concentrations, place them into beakers containing solutions of various concentrations, and record the direction of flow during each experiment.

Experiment 2: enzyme catalysis

  • Enzyme reaction rate is affected by pH, temperature, substrate concentration, and enzyme concentration.
  • To test the rate of reactivity of an enzyme and the difference it makes compared to the speed of the normal reaction, run the reaction without an enzyme, then run it with your enzyme, and compare.
  • To determine the ideal pH (or temperature) for an enzyme, run the reaction at varying pH values (or temperatures) and compare.

Experiment 3: mitosis and meiosis

  • To determine experimentally the percentage of cells in a particular stage of the cell cycle, examine an onion root slide and count the number of cells per stage. Divide the number in each stage by the total number of cells to determine the relative percentages.
  • To determine how far a gene for an ascomycete fungus is from its centromere, cross a wild-type strain with a mutant and examine the patterns among the ascospores. Ratios 4 : 4 (no crossover), 2 : 2 : 2 : 2, or 2 : 4 : 2 (crossover). Total number of crossover divided by total number of offspring = percent crossover. Divide this by 2 to get distance from the centromere.

Experiment 4: plant pigments and photosynthesis

  • To experimentally determine the photosynthetic rate of various plants in various environments, replace NADP+ with DPIP (a compound that changes to a clear color when reduced), and measure the rate of photosynthesis with a spectrophotometer, which determines how much light can pass through a sample. Expose different plants to different environmental conditions, measure how much photosynthesis occurs, and then compare.

Experiment 5: cell respiration

  • To experimentally determine the rate of respiration in peas, use a respirometer to calculate the change in volume that occurs around the peas. Set up (1) a control group of nongerminating peas that will have a lower baseline respiration rate, (2) a control group that measures the change in oxygen due to pressure and temperature changes, and (3) an experimental group that contains the group whose respiration rate you want to measure.
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