SCIENTIFIC THINKING Will increasing atmospheric levels of CO2 make you sneeze as well as itch? Scientists studying the effects of rising CO2 levels have looked at ragweed, whose pollen is the primary allergen for fall hay fever. They grew ragweed in three levels of CO2: a pre-industrial concentration of 280 ppm, a year 2000 level of 370 ppm, and a projected level of 600 ppm. They found that pollen production increased by 131% and 320% in the plants exposed to the recent and projected CO2 levels, respectively. What was the hypothesis of this experiment? Do the results support the hypothesis? Given what you know about climate change, what other variables would you like to test, and what other measurements would you like to take?

Verified step by step guidance

1. Identify the hypothesis of the experiment: The hypothesis likely proposed that increasing levels of atmospheric CO2 would lead to an increase in pollen production by ragweed plants.
2. Analyze the experimental setup: Understand that the experiment involved growing ragweed plants at different CO2 concentrations to observe changes in pollen production.
3. Interpret the results: Compare the increase in pollen production at the year 2000 and projected CO2 levels to the pre-industrial level to determine if the results support the hypothesis.
4. Consider the implications of the results: Reflect on how increased pollen production due to higher CO2 levels could affect allergy sufferers and overall public health.
5. Propose further research: Suggest additional variables to test, such as the effects of varying temperatures or other pollutants on pollen production, and other measurements like the impact on different plant species or the allergenicity of the pollen.

Key Concepts

Hypothesis Formation

A hypothesis is a testable statement that predicts the relationship between variables in an experiment. In this context, the hypothesis likely posits that increased atmospheric CO2 levels will lead to higher pollen production from ragweed, potentially exacerbating allergy symptoms. Understanding how to formulate and evaluate hypotheses is crucial for scientific inquiry and experimentation.

Impact of CO2 on Plant Growth

Carbon dioxide (CO2) is a critical component of photosynthesis, the process by which plants convert light energy into chemical energy. Higher levels of CO2 can enhance plant growth and productivity, which is particularly relevant for allergenic plants like ragweed. This concept is essential for understanding the experimental results, as the increased pollen production correlates with elevated CO2 levels.

Climate Change and Ecosystem Interactions

Climate change encompasses various environmental changes, including rising temperatures and altered precipitation patterns, which can affect ecosystems and species interactions. In the context of this experiment, it is important to consider how other variables, such as temperature and humidity, might influence ragweed growth and pollen production. This broader perspective is vital for assessing the ecological implications of increased CO2 levels.