Question

the data table shown represents the results of an investigation on the amount of co₂ produced by various plant parts over a 3-day period.
amount of carbon dioxide (co₂) in ml
plant part | leaf | stem | root
starting | 200 | 200 | 200
day 1 | 175 | 195 | 220
day 2 | 145 | 180 | 235
day 3 | 90 | 175 | 250
which is an appropriate conclusion for the data shown?
☐ more oxygen was produced in the stem than in the leaf.
☐ the stem was performing photosynthesis at a faster rate than the leaf.
☐ there was no photosynthesis taking place in the roots.
☐ the decrease in carbon dioxide (co₂) for the leaf was less than the decrease for the stem.

Explanation:

1. Analyze Option A: The data is about CO₂, not oxygen production, so A is incorrect.
2. Analyze Option B: Calculate CO₂ decrease (Starting - Day 3): Leaf: \(200 - 90 = 110\) mL, Stem: \(200 - 175 = 25\) mL. Leaf has a larger decrease (more photosynthesis, as photosynthesis uses CO₂), so stem's rate is slower. B is incorrect.
3. Analyze Option C: Root's CO₂ amount increases (200 to 250), meaning no photosynthesis (photosynthesis would use CO₂, decreasing its amount; respiration produces CO₂, increasing it). So C is correct.
4. Analyze Option D: Leaf decrease: \(200 - 90 = 110\) mL, Stem decrease: \(200 - 175 = 25\) mL. Leaf decrease is more than stem, so D is incorrect.

Answer:

C. There was no photosynthesis taking place in the roots.