In high concentrations, hydrogen sulfide (H2S) is typically toxic to many plants. Frederick D. Dooley and colleagues wanted to understand what effects low doses of H2S might have on plant growth. They treated bean, corn, wheat, and pea seeds with various concentrations (measured in micromoles per liter) of H2S and tracked the germination of those seeds along with the germination of untreated seeds. Treatment with particular concentrations of H2S was associated with accelerated germination: for example, ______

Question

Which choice most effectively uses data from the graph to complete the statement?
Choose 1 answer:
Choose 1 answer:
(Choice A) at 168 hours, more than 90% of seeds treated with H2S at concentrations of 10 or 500 micromoles per liter had germinated, whereas less than 70% of untreated seeds had germinated.
A
at 168 hours, more than 90% of seeds treated with H2S at concentrations of 10 or 500 micromoles per liter had germinated, whereas less than 70% of untreated seeds had germinated.
(Choice B) at 48 hours, approximately 50% of seeds treated with H2S at a concentration of 10 micromoles per liter had germinated, whereas only approximately 30% of untreated seeds had germinated.
B
at 48 hours, approximately 50% of seeds treated with H2S at a concentration of 10 micromoles per liter had germinated, whereas only approximately 30% of untreated seeds had germinated.
(Choice C) at 24 hours, less than 10% of seeds treated with H2S at a concentration of 10 micromoles per liter had germinated, whereas more than 90% of those seeds had germinated at 168 hours.
C
at 24 hours, less than 10% of seeds treated with H2S at a concentration of 10 micromoles per liter had germinated, whereas more than 90% of those seeds had germinated at 168 hours.
(Choice D) at 48 hours, more than 70% of seeds treated with H2S at a concentration of 10 micromoles per liter had germinated, whereas only approximately 50% of untreated seeds had germinated.
D
at 48 hours, more than 70% of seeds treated with H2S at a concentration of 10 micromoles per liter had germinated, whereas only approximately 50% of untreated seeds had germinated.

Answer 1

To complete the statement "Treatment with particular concentrations of H2S was associated with accelerated germination: for example, ______," we should look for an option that effectively illustrates the positive impact of low doses of H2S on seed germination compared to untreated seeds.

Let's analyze the choices:

• Choice A: This mentions that at 168 hours, more than 90% of seeds treated with H2S at concentrations of 10 or 500 micromoles per liter had germinated, whereas less than 70% of untreated seeds had germinated. This shows a clear acceleration in germination after a considerable time (168 hours).

• Choice B: At 48 hours, approximately 50% of seeds treated with H2S at a concentration of 10 micromoles per liter had germinated, compared to about 30% of untreated seeds. This also indicates an accelerated germination at an earlier time point.

• Choice C: This reflects that at 24 hours, less than 10% of seeds treated with H2S had germinated, but more than 90% had germinated at 168 hours. It provides an overall picture of growth but may not directly emphasize the acute effect of H2S.

• Choice D: This states that at 48 hours, more than 70% of seeds treated with H2S had germinated compared to roughly 50% of untreated seeds, indicating acceleration as well.

Among these options, Choice B is particularly effective because it demonstrates that a low concentration of H2S (10 micromoles per liter) not only gave a faster germination rate but also did so at an earlier time point (48 hours), thereby directly addressing the question of accelerated germination in a clear and concise manner.

Thus, the best choice is:

(Choice B) at 48 hours, approximately 50% of seeds treated with H2S at a concentration of 10 micromoles per liter had germinated, whereas only approximately 30% of untreated seeds had germinated.