Question

A group of scientists wanted to test the effects of increased greenhouse gas concentrations on plant growth. They hypothesized that elevated levels of CO₂ would increase plant biomass after 2 weeks, whereas elevated levels of N₂O and CH₄ would have no effect. To test this hypothesis, they placed red maple tree saplings in incubators, and then subjected each sapling to one of three treatments. The treatments included 10 ppm of CO₂, N₂O, or CH₄ gas above ambient concentrations. Each treatment had for replicates. After 2 weeks, they measured plant biomass. As hypothesized, the researchers found that plants exposed to elevated CO₂ had increased biomass after 2 weeks, whereas plants exposed to elevated N₂O and CH₄ did not exhibit any change in biomass. Which would be a deductive statement based solely on these results?
A) Elevated levels of CO₂ are due to global climate change
B) Reduced levels of CO₂ due to global climate change will decrease red maple production
C) An observed increase in red maple production is probably due to elevated levels of CO₂
D) Increases in red maple production in nature are probably not due to elevated levels of N₂O or CH₄
E) CH₄ and N₂O are not likely to be biologically important greenhouse gases for tree growth

Answer 1

Answer:

CH₄ and N₂O are not likely to be biologically important greenhouse gases for tree growth

Explanation:

From the discussion of the experiment testing the given hypothesis in the question, all the gases tested, CO2, N2O and CH4 are all green house gases. The aim of the experiment was to ascertain the impact of the selected greenhouse gases on plant biomass. It was observed that CO2 does lead to increase in plant biomass while N2O and CH4 did not.

A proper deduction from the experiment will be 'CH₄ and N₂O are not likely to be biologically important greenhouse gases for tree growth'.