MODULE 1

• Which of the following questions would be best addressed through manipulative experiments?

  1. What is the effect on variable Y of manipulating variable X?
  2. Can we establish a cause-and-effect relationship between factors A and B?
  3. What patterns and relationships exist in this ecosystem without interventions?
  4. How can we control for confounding variables in an experiment?

  Can we establish a cause-and-effect relationship between factors A and B?
• True or false

  It is difficult to directly infer causality in mensurative experiments due to the high potential of confounding factors.

  True
• True or false

  Mensurative experiments are purely observational studies where the experimenter controls the environmental variable/s.

  False
• True or false

  Mensurative experiments are comparative studies that involve two or more treatments

  False
• True or false

  Mensurative experiments are more difficlt to conduct at both large and small spatial scales than manipulation experiments.

  False
• Which of the the key advantage of manipulative experiments in ecological research?

  Establishing causal relationships between variables.
• In manipulative experiments, what is the emphasis when selecting study sites or subjects?

  Ensuring homogeneity to control for confounding variables.
• What distinguishes manipulative experiments from mensurative experiments?

  The ability to manipulate and control variables.
• True or false

  Science makes progress by disproving most of the alternative explanations. What is not disproven is, in effect, indirectly proven.

  True
• In mensurative experiments, what is the role of researchers in relation to the variables being studied?

  Manipulate variables to observe their effects.
• What is the significance of refined and revised hypotheses during follow-up experiments?

  It allows for adaptation based on emerging data and observations.
• Situation: Hydrangeas in container 1 have pink blossoms, while container 2 have blue blossoms. All of them were grown from the same seed variety and same soil type. However, the soil in container 1 has a pH of 6 whereas container 2 has a pH of 5. Which question is best suited in this situation?

  • What type of soil will produce a hydrangea with both pink and blue blossoms?
  • How does chemistry of the soil afect the color od hydrangea blossoms?
  • Do varying degrees of light affect hydrangea blossoms?
  • What role do genetic factrs play in hydrangea color?
• Situation: Hydrangeas in container 1 have pink blossoms, while container 2 have blue blossoms. All of them were grown from the same seed variety and same soil type. However, the soil in container 1 has a pH of 6 whereas container 2 has a pH of 5. Which bullet point is best suited in this situation?

  • What type of soil will produce a hydrangea with both pink and blue blossoms?
  • How does chemistry of the soil afect the color od hydrangea blossoms?
  • Do varying degrees of light affect hydrangea blossoms?
  • What role do genetic factrs play in hydrangea color?

  Right answer: Second bullet point
• Which of the following is an example of a well-formulated null hypothesis?

  1. Soil pH has a positive correlation with insect diversity.
  2. Predator presence has a negative impact on prey survival.
  3. More exposure to full sunlight will lead to higher plant growth.
  4. There is no difference in bird population densities between the two habitats.

  There is no difference in bird population densities between the two habitats.