RP10

• How can a choice chamber be used to measure the favourable environment of a small organism?

  By setting up chambers in different quadrants with different environmental conditions: dark + dry, dark + damp, light + dry, light + damp Organisms will move to the quadrant they find favourable
• What factors must be controlled when repeating the experiment?

  Number of animals

  Environmental conditions

  Time allowed for animals to choose
• Which statistical test is used to analyse the

  Chi squared test.

  It compares the expected and observed values, and tests if there is a significant difference.
• What is the conclusion drawn if the calculated value is greater than the critical value?

  Null hypothesis is rejected.

  Less than 5% probability that the difference is due to chance alone.

  There is a statistically significant difference between the expected and observed values.
• What do animals do when they are in unfavourable environments?

  They move faster and change direction more frequently to increase their chances of survival.
• State the hazard and precaution involved in this practical.

  The live organisms used are a biohazard. Wash hands after handling.