Exam Questions Flashcards
Transgenerational Study—Can It Differentiate Between Transgenerational Effects and Phenotypic Plasticity?
Combined Effect of Acidification and Copper on Tropic Coral (Stylophora pistillata)—Problems with the Paper
What is a multifactorial experimental design, and why is it important in environmental studies?
If there is limited space and not all combinations of factors can be tested, what approach can be taken?
What is pseudoreplication, and how can it affect an experiment’s validity?
Why should the “tank” be included as a random factor in the design?
How many replicates are typically recommended for experiments involving random factors?
At least three replicates per factor level.
How can “time” be included as a factor in an orthogonal design?
(Cryer paper)
What were the main problems with the Cryer paper on corals (Stylophora pistillata)?
What statistical mistake did the Cryer paper make?
(Cryer paper)
Why was the lack of feeding during the experiment problematic?
Starvation weakened the corals, making it difficult to attribute changes to copper and OA stress rather than nutritional deficits.
What is an orthogonal design in an experiment?
An experimental design where all factor levels are crossed, allowing independent and unbiased estimates of the effects of each factor and their interactions.
What happens if space constraints prevent an orthogonal design?
Simplified designs (e.g., collapsing levels into combined future vs. current conditions) can be used, but interpretation is limited since factor interactions may be conflated.
What does it mean for a red stress condition to become the “new ambient” condition?
How can experiments differentiate between transgenerational effects and phenotypic plasticity?
How can the number of tanks in an experiment be reduced without compromising the study’s validity?
What is the hypothesis when polyps lose their coenosarc in response to environmental stress?
The colony may switch from a “colony survival” strategy to a “single-polyp survival” strategy due to resource limitations under stress.
What considerations should be made when selecting sites and depths for field studies?
What did the natural CO₂ vents in Ischia demonstrate about environmental adaptation?
Draw and describe an experiment used to distinguish phenotypic plasticity and transgenerational effects in response to a stressor or combination of stressors.
Describe random and fixed factors and design an experiment with both types of factors.
Describe an experimental design aimed at showing the buffer effects of macroalgae.
Define the experimental problem in Cryer et al.
What were the objectives of the De Marchi et al. paper and how were they demonstrated through the experimental setup and results?
- To investigate the toxic effects of caffeine (CAF) on two bioindicator species: the clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis.
- To determine if these effects were amplified by the presence of dynamic temperature fluctuations, simulating marine heatwaves (MHWs).
Draw and describe an experiment used to distinguish phenotypic plasticity and transgenerational effects in response to a stressor or combination of stressors.
Explain the difference between fixed and random factors with an example from an ecotoxicological context. Design an experiment to test the effects of a fixed factor (e.g., pH) and a random factor on the immune response of a marine bivalve.
Experimental Design: Testing the Effects of a Fixed Factor (pH) and a Random Factor (Sampling Location) on the Immune Response of a Marine Bivalve
Objective:
To investigate how pH (fixed factor) and location (random factor) influence the immune response of a marine bivalve species (e.g., Mytilus galloprovincialis).
Discuss the importance of avoiding pseudoreplication in ecotoxicology studies. Propose a study to test heavy metal toxicity (e.g., copper) on marine invertebrates, ensuring no pseudoreplication occurs.
Propose an experimental design to distinguish between phenotypic plasticity and transgenerational effects of ocean acidification in Pseudocalanus acuspes. Specify the generational treatments and expected outcomes.
Explain how exposure to extreme CO₂ conditions (e.g., 1550 µatm) might irreversibly impact the reproductive output of a zooplankton species.
Describe the use of biomarkers in ecotoxicology. Design a study to evaluate oxidative stress biomarkers in response to exposure to a common pollutant (e.g., copper or caffeine) in Chamelea gallina.
What are lipid peroxidation and antioxidant enzymes? How would you incorporate these as biomarkers to assess the effect of marine heatwaves on the physiological performance of Mytilus galloprovincialis?
Identify three key design flaws in Cryer et al.’s study on coral responses to ocean acidification and copper exposure. Suggest modifications to improve the ecological relevance and statistical robustness of the study.
In a study investigating the combined effects of caffeine and marine heatwaves, the researchers failed to include a control group for heatwaves alone. Discuss the implications of this omission and suggest an improved experimental setup.
Design an experiment to test the hypothesis that Posidonia oceanica buffers the effects of ocean acidification on calcifying organisms. Specify the factors, levels, and dependent variables.
Discuss the ecological importance of canopy-forming macroalgae in mitigating environmental stressors. How could this information guide conservation efforts in the Mediterranean Sea?
Outline a multifactorial experiment to assess the interactive effects of salinity and pH on the immune response of blue crabs (Callinectes sapidus). Include orthogonal factors, levels, and response variables.
Explain the concept of hierarchical designs in experimental ecology. Provide an example where a factor (e.g., habitat type) is nested within another factor (e.g., region) to study variability in biomarker responses.
Evaluate the findings from Teixido et al.’s study on coral phenotypic shifts under different pH levels. What does the transition from colonial forms to solitary polyps indicate about the survivability of calcifying species in low-pH environments?
Discuss how diel changes in oxygen levels in vegetated coastal habitats can enhance the survival of marine ectotherms under warming conditions. Design an experiment to test this phenomenon.
Discuss the appropriateness of using one-way ANOVA in multifactorial designs. Propose a more suitable statistical analysis for a study testing interactions between ocean acidification and temperature on coral growth.
Explain the importance of replication in experimental designs. If space is limited and fewer tanks can be used, how would you modify an experiment to ensure reliable and valid results?
how to proceed an experiment under limitations?
