Paper 2 practicals

• What is the aim of the ruler drop test?

  Investigate the effect of practice on reaction time
• What equipment is required for the ruler drop test?

  Metre ruler, chair, table
• What are the steps to perform the ruler drop test?

  1. Sit on a chair with forearm on table.
  2. Partner holds ruler between fingers.
  3. Remove fingers from ruler.
  4. Partner aligns ruler with thumb.
  5. Partner drops ruler unexpectedly.
  6. Catch the ruler and record measurement.
  7. Repeat at least 5 times.
  8. Swap roles and repeat.
  9. Convert ruler measurements to reaction times.
• How should participants position their forearm during the test?

  Forearm on the table with hand hanging
• Why should the partner hold the ruler in line with the thumb?

  To ensure accurate measurement of reaction time
• How many times should the test be repeated?

  At least 5 times
• What should participants do after catching the ruler?

  Record the number level with the thumb
• What is a potential source of error in the ruler drop test?

  Participants may have different prior experiences
• Why might the sample size affect the validity of the conclusion?

  A small sample may not represent the population
• What is needed to find reaction times after the test?

  A conversion table for ruler measurements
• What are the steps to record the results of the ruler drop test?

  • Record ruler measurements in cm.
  • Calculate reaction times in seconds.
  • Use a table to organize data.
• What is the aim of the investigation?

  Investigate light or gravity effects on seedlings
• What equipment is needed for the investigation?

  • White mustard seeds
  • Petri dishes
  • Cotton wool
  • Ruler
  • Water
  • Window with light exposure
  • Dark cupboard
• What is the first step in the method?

  Pour a fixed volume of water into petri dishes
• How many seeds should be placed in each petri dish?

  10 seeds
• Where should the petri dishes be placed during germination?

  In a warm location, like an incubator
• What should be done if not all seeds germinate?

  Remove excess seedlings for uniformity
• What are the environmental conditions for the experiment?

  • Full sunlight
  • Partial sunlight
  • Darkness
• How should the height of seedlings be measured?

  Using a ruler every day for a week
• What should be recorded in a table?

  Height of each seedling daily
• What is the next step after measuring seedling height?

  Find the mean height of seedlings each day
• What should be plotted on a graph?

  Mean height of seedlings against day
• What are the sources of error in the experiment?

  • Unequal sunlight exposure in petri dishes
  • Small sample size for each condition
  • Temperature variations affecting growth
• What is a risk associated with handling seeds?

  Seeds may be a biohazard
• What precaution should be taken after handling seeds?

  Wash hands
• What is the aim of the field investigation?

  Estimate plant population size and distribution
• What is the purpose of random sampling in this investigation?

  To estimate the population size of a plant species
• What does continuous sampling with a transect line investigate?

  The effect of variation in a factor on plant distribution
• What equipment is needed for the field investigation?

  • Frame quadrat (25 cm by 25 cm)
  • Tape measures
  • Clipboard
  • Pen
  • Paper
• How do you obtain coordinates for placing the quadrat in part A?

  Use a random number generator
• What should you do after placing the quadrat at the coordinates?

  Count and record the number of required plants
• How many samples should be taken in part A?

  Ten samples
• What formula is used to estimate the population size in part A?

  Area sampled / total area x number of plants counted
• What should be written down before starting part B?

  A hypothesis about an abiotic factor's effect
• Where should the tape measure be laid in part B?

  From the base of a tree to an open area
• How should the quadrat be placed along the tape measure?

  With one corner touching the '0' mark
• What should be done after counting the plants in the quadrat?

  Record the count in a table
• How often should the quadrat be moved along the tape measure?

  Every 5 meters
• What should be done with the data collected from the class?

  Find the mean number of plants at each point
• What type of graph should be plotted with the data collected?

  Number of plants against the ecological gradient