ACT Success - Science - Practice #6

Group 1

Source 1.1

• The number of colonies would continue to increase.

• The number of colonies would decrease to zero by Day 10.

• The number of colonies would stabilize at a low level.

• The number of colonies would likely fluctuate around 10 colonies.

• Higher than the no-oil condition but lower than the 5% oil condition.

• Between the 5% oil and 20% oil conditions.

• Equal to the 20% oil condition.

• Lower than the no-oil condition.

• Bacteria are inhibited by any amount of oil.

• Higher oil concentrations initially encourage bacterial growth up to a certain level.

• Bacterial growth is directly proportional to oil concentration over time.

• Bacterial growth is unaffected by oil concentration.

Group 2

Source 2.1

• Limestone, because of its small particle size.

• Shale, due to its moderate particle size.

• Slate, since it shows the least variation in height.

• A combination of shale and slate.

• Slate peaks would likely show a consistent loss of height.

• Slate peaks would likely maintain or gain height over time.

• Slate peaks would experience greater variation in height changes.

• Slate peaks would likely erode faster than other sediment types.

• It would suggest that limestone is more resistant to erosion than previously thought.

• It would mean that slate contributes more to height gain than shale.

• It would imply that shale is not as stable as initially interpreted, leading to larger height losses.

• It would indicate that all sediment types contribute equally to peak height loss.

Group 3

• A discovery of dinosaur fossils in regions unaffected by volcanic ash, suggesting they lived in isolated pockets after the extinction event.

• Sediment analysis indicating high levels of iridium worldwide, which is associated with asteroid impacts.

• Geological layers containing sulfur dioxide and carbon dioxide deposits from volcanic sources, dated to the time of the extinction.

• Evidence showing that mammal populations increased significantly just before the dinosaur extinction.

• Fossil evidence showing that large numbers of dinosaur species died out within a very short period.

• The discovery of volcanic ash layers in rocks from the extinction period, suggesting a volcanic eruption.

• Analysis showing that iridium levels spiked in the fossil record exactly at the time dinosaurs disappeared.

• Studies finding that mammals and dinosaurs occupied separate ecological niches with minimal resource overlap.

• Increased photosynthesis in autumn decreases carbon dioxide levels, raising the pH of the lakes.

• Increased rainfall in spring dilutes the water, lowering the pH of the lakes.

• Bacterial decomposition in autumn raises carbon dioxide levels, lowering the pH of the lakes.

• Melting snow in spring releases acidic compounds into the lakes, lowering the pH.

• Higher temperatures decrease oxygen levels directly.

• Algae thrive at high temperatures and deplete oxygen as they grow.

• Algae release oxygen as they grow, leading to increased oxygen levels.

• Oxygen levels in the lake are unaffected by temperature changes.

• Both species would thrive when moisture is at 80%.

• Only Species B would survive when moisture drops to 10%.

• Both species would have optimal growth at 70% soil moisture.

• Species A would grow best at 60% soil moisture, while Species B would grow best at 30%.

• The rate of photosynthesis would increase continuously.

• The rate of photosynthesis would remain stable but high.

• The rate of photosynthesis would decline due to light stress.

• The rate of photosynthesis would drop to zero.

• An environment where salinity fluctuates between 6% and 8%.

• An environment where salinity is consistently around 2%.

• An environment where salinity remains above 10%.

• An environment where salinity fluctuates between 5% and 10%.