ACT Exams- Science 2 - My Exams Help

1.

Passage: Scientists recorded bird songs and calls in a forest at different times of day and year.

Question: How might the data collected vary between morning/evening or winter/summer? Explain your reasoning.

A) Songs would be shorter at night and less complex in winter to conserve energy.

B) Calls would be longer during breeding season and contain more location-specific elements.

C) Variations in temperature and precipitation could impact recording quality between seasons.

D) No differences would be expected since birds sing at a consistent rate all day and year.

2.

Passage: Water samples from five reservoirs were tested for pH, dissolved oxygen, and E. coli levels.

Question: Discuss possible patterns that may have been observed. Suggest reasons for any correlations between measurements. Identify ways to strengthen conclusions about water quality.

A) Lower pH and DO with higher E. coli near populated areas due to pollution runoff. Long-term averages accounting for weather needed.

B) Independent of location, pH negatively correlates to DO but neither predict E. coli. Additional chemical/biological parameters would aid analysis.

C) No consistent relationships, required better Instrument calibration and standardized sampling procedures.

D) DO always highest while pH lowest, showing inverse relationship. Single snapshots sufficient to characterize each reservoir.

3.

Passage: In an experiment, plants were grown with fertilizer solutions of different NPK concentrations.

Question: Outline hypotheses for how plant growth might respond. Design controls and validate results. Consider potential sources of error. Suggest extensions to study nutrient uptake.

A) Higher concentration leads to greater growth but risks toxicity. Include water-only control and measure across genotypes. Account for temperature/light variations. Analyze tissue nutrient levels at harvest.

B) Growth maximizes at mid-range levels due to balanced supply. Replicate with different growing media and quantitate uptake kinetics.

C) Response follows Liebig’s Law of Minimum. Isolate each variable and test over wider dose ranges.

D) No effect since these are minor constituents; other factors like CO2 determine yield. No further work required.

4.

Passage: Exoplanets were discovered orbiting a distant star. Their sizes and orbital periods were measured.

Question: Analyze the system. Using principles of physics, infer interior/surface properties. Design follow-up observations. Consider instrumentation limitations. Propose further insights obtainable from ongoing research.

A) Larger worlds likely rocky, smaller gaseous. Expect volcanism on some. Monitor transits for atmospheric data. Spectroscopy could reveal compositions. Orbital resonance may exist.

B) Insufficient data to characterize exoplanets. Need higher resolution imaging and gravity measurements to constrain properties.

C) All are gaseous giants as terrestrials cannot form elsewhere. This single system offers no new insight; focus elsewhere is warranted.

D) Only speculative inferences can be made without distance/mass determinations. Future space-based observatories may provide necesary data.

5.

Passage: Researchers studied adaptation of a fish species to varying salinity levels in estuarine environments.

Question: Hypothesize how physiology might differ between freshwater and saltwater populations. Outline experiments to test ideas. Consider controls and quantification methods.

A) Gill morphology may adjust. Measure ion transport rates in plasma membranes isolated from diverse locales.

B) Hemoglobin function likely optimizes O2 affinity. Quantify tissue metabolic enzyme activities at a range of salinities.

C) No heritable change occurs. Plastic trait responses suffice for tolerance across salinities.

D) Osmoregulatory gland activity adjusts to balance fluids. Microarray analysis could reveal gene expression divergences.

6.

Passage: A tropical plant is suspected of attracting pollinators through scent. Experiments test effects of isolated volatile compounds on insects in a wind tunnel.

Question: Identify strengths and limitations of this design. Suggest validations or complementary analyses. Consider ecological and evolutionary implications.

A) Lacks realism but enables control. Assess blends/ratios next. Monitor recruitment, fitness, gene flow over generations.

B) Fails to capture nuanced multi-sensory interactions. Field censusing further elucidates natural pollinator relationships.

C) Artificial conditions preclude insight. Abandon manipulating scents; simply observe natural systems.

D) Reduces complexity appropriately. Gas chromatography–mass spectrometry identifies compounds insects detect best.

7.

Passage: Correlation between coastal upwelling and salmon abundance along western North America spans centuries. Analysis of isotopic profiles in annual growth rings of long-lived trees suggests covariation.

Question: Critique evidence and propose valid causal explanation. Design alternative tests considering sediment/geologic archives. Address uncertainties and avenues for strengthening inferences about past ecosystem linkages.

A) Insufficient data preclude conclusions. Need direct ecological observations over space/time rather than proxy records alone.

B) Upwelling drives productivity sustaining salmon, locking populations together. Resolving annual bands in varved lake sediments expands records.

C) Correlation vs causation fallacy. Trees record only local climate while fish respond to coast-wide oceanographic patterns.

D) Rings conflate marine and terrestrial factors in unclear manners unrepresentative of specific habitats and resources.

8.

Passage: RNA extracted from fossil bones millions of years old was sequenced, revealing intact mitochondrial genes. Proteins were also identified.

Question: Critique findings based on scientific principles. Hypothesize preservation mechanisms. Design experiments to validate claims considering contamination concerns. Explain what insights could differentiate endogenous signals from artifacts.

A) Improbable without mineralization inhibiting degradation. Open-air excavations risk microbiome infiltration. Replicate in labs using controlled taphonomy on diverse tissues.

B) Remarkable but requires independent corroboration utilizing complementary geochemical analyses of bone microstructure and encasing sediments.

C) Fabrication without supporting geochronology or consistency across specimens. Abandon unreliable biomolecule analyses of ancient fossils.

D) Novel if authentic. Single-molecule DNA techniques interrogating template damage patterns lend Authigenicity signatures of sequences.

9.

Passage: Soil dwelling nematodes inhabit both bacteria-consuming and plant-parasitic trophic levels. Population surveys followed exclusion plots treated with different pest-control chemicals.

Question: Hypothesize treatment impacts on nematode community structure. Outline long-term monitoring with control replication to track indirect ecological effects. Consider statistical analyses and uncertainty quantification.

A) Targeted poisons may reduce parasites but stimulate bacterial feeders via competitive release over years. Compare diversity/evenness indices annually.

B) Nematodes rapidly recolonize post-disturbance. Single snapshots fail distinguishing natural variation from potential treatment signatures.

C) As generalists, responses depend on non-target prey. Microcosms enable dose-response curves for keystone taxa.

D) Inconclusive without linking abundances to crop performance independently of agrochemical applications.

10.

Passage: Fossilized compounds resembling carotenoid pigments were extracted fromPermian period sediments and marine invertebrate shells.

Question: Formulate testable paleobiological hypotheses regarding ancient chemistries and ecologies. Tailor investigative strategies to limitations of the geological record and extinct biota.

A) Red pigments may indicate photosynthetic or light-harvesting roles like today. Combine with geochemical tracers of environmental oxygen and energy fluxes over eras.

B) Extractions questionably reflect original biology rather than diagenetic alteration. Multi-proxy isotope analyses of co-occurring fossils refine environmental context of molecular fossils.

C) Speculative without technological capacity for further analysis of degraded biomarkers. Focus progressing expertise on material amenable to modern techniques that offer new insight.

D) Physical and temporal constraints prevent meaningful inference from trace chemical signals of deep time. Limit paleontological pursuits to skeletons.