ACT Science : Biology

Study concepts, example questions & explanations for ACT Science

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Example Questions

Example Question #631 : Biology

     Species competition is driven by a variety of factors. Resources such as water, food, sunlight, and suitable habitat are among the top contributors that influence interspecific and intraspecific competition. Interspecific is competition between different species and intraspecific competition is between members of the same species.

     One interesting example of interspecific completion is that of two barnacle species that inhabit intertidal zones. Balanus balanoides inhabits the lower intertidal zone and Chthamalus stellatus inhabits the lower intertidal zone. A researcher attempts to study this phenomenon.

     The researcher removes the Balanus species from the lower intertidal zone and observes that the Chthamalus species expands its range to inhabit the lower intertidal zone and the upper intertidal zone. The researcher then removes the Chthamalus species from the upper tidal zone of a different area and observes that the Balanus species does not extend its range. The researcher concludes that competition has allowed each species to exist simultaneously by forming specialized niches that promotes survivorship for each species.

A new study investigated the tides effect on water levels in relation to species diversity. It suggests that the Balanus species is absent from the upper intertidal zone due to issues involved with dessication (drying out). How would the researcher react to this claim?

Possible Answers:

The researcher would agree because data on tidal effects on ocean water levels was absent in the barnacle study.

The researcher would disagree because these results do not correspond with collected data.

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The researcher would disagree because the two species would not inhabit the same space despite tidal influences.

The researcher would agree with the claim because it corresponds with the data that was collected.

Correct answer:

The researcher would agree with the claim because it corresponds with the data that was collected.

Explanation:

The researcher would agree with the claim because it corresponds with the data that was collected.

This is the correct answer because the new study contains information that aids in the explanation of the observed results of the researcher's initial investigation. The Balanus species does not inhabit the upper intertidal zone. The data in the new study supports this information with a possible explanation for the niche forming abilities of the new species. None of the other choices are supported by the passage.

Example Question #632 : Biology

     Criminal and deviant acts have plagued society for many years. Scientists have tried to isolate variables and factors of individuals susceptible to these behaviors. The goal of this research is to create models of individuals most likely to commit deviant acts. Prediction of criminal behavior could reduce crime rates on a grand scale. Three scientists express their views on how to model criminal behavior and predict or prevent criminal acts.

Scientist 1

     Criminal behavior is the result of prehistoric tendencies that favor aggressive and deviant acts for survival. A study of the corpses of criminals revealed that many exhibited prominent brows, strong upper bodies, large chests and other attributes that lend to a physical model of prediction that classifies criminals as "evolutionary throwbacks."

Scientist 2

     Criminal behavior is the result of psychological ills that may be remedied with treatment and hospitalization. Studies have revealed that many criminal men possess an XYY makeup. This means that they contain one extra Y chromosome that results in aggressive, deviant, and criminal behaviors. Further studies have revealed that these genetic abnormalities can alter hormonal secretion and lead to criminally deviant actions and behaviors. Increased serotonin levels can lead to aggressive tendencies while altered dopamine secretion can chemically reward the commitment of deviant acts by stimulating pleasure receptors.

Scientist 3

     Criminal behavior is the result of neurological abnormalities that can be studied and mapped. Studies of criminal and non-criminal persons have revealed inconsistencies in brain scans and neurological makeup. These alterations in brain chemistry and function have resulted in the development of sociopathic and narcissistic tendencies. These tendencies often increase probabilities for deviant and violent outbursts. The best way to predict criminal behavior is to utilize neurological scanning and mapping procedures.

An archeological study has revealed that aggressive tendencies may have enhanced survival techniques of primitive man and may still play an evolutionary role in the development of modern man. Which scientist would most agree with this evidence?

Possible Answers:

Scientist 2

Scientist 3

Scientist 1

None of the scientists would agree with this information.

Correct answer:

Scientist 1

Explanation:

Scientist 1 would agree with this information because it directly corroborates his view on criminal behaviors. The physical/evolutionary model of crime prediction is based on the idea that criminals exist as remnants from the past. They are a subspecies of modern man that exhibit traits common to aggressive ancestors. The evidence in the study suggests that aggressive tendencies enhance survival and therefore may not be completely absent from the development of modern man.

Example Question #633 : Biology

    Criminal and deviant acts have plagued society for many years. Scientists have tried to isolate variables and factors of individuals susceptible to these behaviors. The goal of this research is to create models of individuals most likely to commit deviant acts. Prediction of criminal behavior could reduce crime rates on a grand scale. Three scientists express their views on how to model criminal behavior and predict or prevent criminal acts.

Scientist 1

     Criminal behavior is the result of prehistoric tendencies that favor aggressive and deviant acts for survival. A study of the corpses of criminals revealed that many exhibited prominent brows, strong upper bodies, large chests and other attributes that lend to a physical model of prediction that classifies criminals as "evolutionary throwbacks."

Scientist 2

     Criminal behavior is the result of psychological ills that may be remedied with treatment and hospitalization. Studies have revealed that many criminal men possess an XYY makeup. This means that they contain one extra Y chromosome that results in aggressive, deviant, and criminal behaviors. Further studies have revealed that these genetic abnormalities can alter hormonal secretion and lead to criminally deviant actions and behaviors. Increased serotonin levels can lead to aggressive tendencies while altered dopamine secretion can chemically reward the commitment of deviant acts by stimulating pleasure receptors.

Scientist 3

     Criminal behavior is the result of neurological abnormalities that can be studied and mapped. Studies of criminal and non-criminal persons have revealed inconsistencies in brain scans and neurological makeup. These alterations in brain chemistry and function have resulted in the development of sociopathic and narcissistic tendencies. These tendencies often increase probabilities for deviant and violent outbursts. The best way to predict criminal behavior is to utilize neurological scanning and mapping procedures.

Thy hypothalamus is the part of the brain that is responsible for aggressive behaviors and tendencies. A recent study has suggested that peeple who are more likely to engage in physical altercations possess larger hypothalamus regions. Which of the scientists would most likely agree with this information?

Possible Answers:

Scientist 2

Scientist 1

Scientist 3

None of the scientistswould agree with this information

Correct answer:

Scientist 3

Explanation:

The views of Scientist 3 are directly supported by this evidence. Scientist 3 concludes that criminal behavior is the result of altered brain wiring and composition. The study mentioned relates directly to altered brain composition by indicating  that aggressive individuals have a larger hypothalamus region. 

Example Question #634 : Biology

     Criminal and deviant acts have plagued society for many years. Scientists have tried to isolate variables and factors of individuals susceptible to these behaviors. The goal of this research is to create models of individuals most likely to commit deviant acts. Prediction of criminal behavior could reduce crime rates on a grand scale. Three scientists express their views on how to model criminal behavior and predict or prevent criminal acts.

Scientist 1

     Criminal behavior is the result of prehistoric tendencies that favor aggressive and deviant acts for survival. A study of the corpses of criminals revealed that many exhibited prominent brows, strong upper bodies, large chests and other attributes that lend to a physical model of prediction that classifies criminals as "evolutionary throwbacks."

Scientist 2

     Criminal behavior is the result of psychological ills that may be remedied with treatment and hospitalization. Studies have revealed that many criminal men possess an XYY makeup. This means that they contain one extra Y chromosome that results in aggressive, deviant, and criminal behaviors. Further studies have revealed that these genetic abnormalities can alter hormonal secretion and lead to criminally deviant actions and behaviors. Increased serotonin levels can lead to aggressive tendencies while altered dopamine secretion can chemically reward the commitment of deviant acts by stimulating pleasure receptors.

Scientist 3

     Criminal behavior is the result of neurological abnormalities that can be studied and mapped. Studies of criminal and non-criminal persons have revealed inconsistencies in brain scans and neurological makeup. These alterations in brain chemistry and function have resulted in the development of sociopathic and narcissistic tendencies. These tendencies often increase probabilities for deviant and violent outbursts. The best way to predict criminal behavior is to utilize neurological scanning and mapping procedures.

A study of mice revealed that males possessing an XYY genotype are far more likely to engage in risky and aggressive behaviors. Which of the scientists would most agree with this evidence?

Possible Answers:

None of the scientists would agree with this information.

Scientist 1

Scientist 2

Scientist 3

Correct answer:

Scientist 2

Explanation:

Scientist 2's model is based on hormonal/chemical secretion and genetic structure. The mice in the study possess a XYY genotype. This genotype was referenced in Scientist 2's viewpoint. The other scientists believe criminal acts are either evolutionary or the cause of a defect in brain structure, not chemisry.

Example Question #635 : Biology

     Criminal and deviant acts have plagued society for many years. Scientists have tried to isolate variables and factors of individuals susceptible to these behaviors. The goal of this research is to create models of individuals most likely to commit deviant acts. Prediction of criminal behavior could reduce crime rates on a grand scale. Three scientists express their views on how to model criminal behavior and predict or prevent criminal acts.

Scientist 1

     Criminal behavior is the result of prehistoric tendencies that favor aggressive and deviant acts for survival. A study of the corpses of criminals revealed that many exhibited prominent brows, strong upper bodies, large chests and other attributes that lend to a physical model of prediction that classifies criminals as "evolutionary throwbacks."

Scientist 2

     Criminal behavior is the result of psychological ills that may be remedied with treatment and hospitalization. Studies have revealed that many criminal men possess an XYY makeup. This means that they contain one extra Y chromosome that results in aggressive, deviant, and criminal behaviors. Further studies have revealed that these genetic abnormalities can alter hormonal secretion and lead to criminally deviant actions and behaviors. Increased serotonin levels can lead to aggressive tendencies while altered dopamine secretion can chemically reward the commitment of deviant acts by stimulating pleasure receptors.

Scientist 3

     Criminal behavior is the result of neurological abnormalities that can be studied and mapped. Studies of criminal and non-criminal persons have revealed inconsistencies in brain scans and neurological makeup. These alterations in brain chemistry and function have resulted in the development of sociopathic and narcissistic tendencies. These tendencies often increase probabilities for deviant and violent outbursts. The best way to predict criminal behavior is to utilize neurological scanning and mapping procedures.

A congressman argues that detection and remediation are important in the process of controlling crime. He decides to interview and hire one of the scientists to work on a federal level. Which scientist is he most likel to choose?

Possible Answers:

Scientist 2

Scientist 1

None of these candidates would be hired

Scientist 3

Correct answer:

Scientist 2

Explanation:

Scientist 2 is the only candidate that proposes possibly remediation of criminal tendencies via treatment and hospitalization. Both of the other scientists state that criminal behavior is the product of evolutionary tendencies or incorrect brain development that make criminals inherently "bad." Neither, present a method of treatment.

Example Question #636 : Biology

     A common phenomenon in aquatic plant growth and development is the effects of a limiting nutrient. A limiting nutrient is one that has the ability to stunt or halt plant growth and development if its stores are depleted in the soil or plant itself.  Limiting nutrients include nitrogen and phosphorus. These nutrients are usually tightly bound to soil particles and not available for direct use. In response, plants produce and release enzymes. Enzymes release bound particles in order for the plant to actively transport nutrients from the soil. Two scientists express their views on enzyme nutrient interactions within an aquatic biome.

Scientist 1

     The reaction is inducible. As the plant senses cues from phosphorus in the soil, it develops and releases enzymes to obtain the nutrients it needs. In this way, the plant obtains nutrients, preserves biological energy, and maintains fitness.

Scientist 2

     The reaction is coincidental. Plants are biologically primed to create stores of phosphatase enzymes in order to obtain environmental nutrients. Therefore, fitness and energy costs are inconsequential.

Researchers investigate the phenomenon and find that plants that utilize phosphatase enzymes possess decreased fitness and energy levels; however, these levels increase after nutrients are acquired.

Which scientist would agree with this evidence?

Possible Answers:

Scientist 2

Both

Scientist 1

Neither

Correct answer:

Scientist 1

Explanation:

Scientist 1 would support this data. This scientist believes the effect is inducible. Therefore, the organism can conserve energy and fitness by only creating phosphatase enzymes as needed. This enables it to obtain nutrients as needed rather than creating vast stores of phosphatase at high energy costs.

Example Question #637 : Biology

     A common phenomenon in aquatic plant growth and development is the effects of a limiting nutrient. A limiting nutrient is one that has the ability to stunt or halt plant growth and development if its stores are depleted in the soil or plant itself.  Limiting nutrients include nitrogen and phosphorus. These nutrients are usually tightly bound to soil particles and not available for direct use. In response, plants produce and release enzymes. Enzymes release bound particles in order for the plant to actively transport nutrients from the soil. Two scientists express their views on enzyme nutrient interactions within an aquatic biome.

Scientist 1

     The reaction is inducible. As the plant senses cues from phosphorus in the soil, it develops and releases enzymes to obtain the nutrients it needs. In this way, the plant obtains nutrients, preserves biological energy, and maintains fitness.

Scientist 2

     The reaction is coincidental. Plants are biologically primed to create stores of phosphatase enzymes in order to obtain environmental nutrients. Therefore, fitness and energy costs are inconsequential.

According to the information provided, which views would be accepted by both scientists?

Possible Answers:

Plants utilize enzymes to respond to biological cues and obtain essential nutrients.

There is no correlation between biological fitness and enzyme production.

Limiting nutrients only affect plants that live in nutrient-deprived areas. Otherwise, they may substitute other nutrients for survival.

Runoff and pollution has increased phosphorus levels in aquatic biomes and made nutrient acquisition via phosphatase enzymes inessential for survival.

Correct answer:

Plants utilize enzymes to respond to biological cues and obtain essential nutrients.

Explanation:

Plants utilize enzymes to respond to biological cues and obtain essential nutrients.

This is the correct answer because both scientists agree that plants release enzymes in order to obtain particle bound nutrients.

Runoff and pollution has increased phosphorus levels in aquatic biomes and made nutrient acquisition via phosphatase enzymes inessential for survival.

This is incorrect because no information supports this theory or view.

There is no correlation between biological fitness and enzyme production.

This is incorrect because both scientists disagree on the relationship between biological fitness and a plant's use of enzymes.

Limiting nutrients only affect plants that live in nutrient-deprived areas. Otherwise, they may substitute other nutrients for survival.

This is incorrect because no evidence in the passage supports it.

Example Question #638 : Biology

     Invasive species lack the natural competitors in a given area to properly regulate population growth and development. Myriophyllum spicatum is a Eurasian milfoil. It was first used in the United States as an aesthetic for aquatic fish tanks. Later, it was accidentally introduced into local ponds and lakes where it became a dominant invasive species and has began to choke out native and naturally occurring plant life. To make matters worse, phosphorus-rich fertilizers and cleaners have contaminated many freshwater biomes due to runoff and pollution. As a result, many standing freshwater pools contain heavy amounts of phosphorus. These species readily utilize the phosphorus and have become nearly unmanageable. Two ecologists express their views on how to control the invasive population.

Ecologist 1

     The best way to control the problem is to limit the nutrients in the biome. If the nutrients are controlled then the plants will be unable to grow and flourish. After several generations, the nutrients will be depleted and the plant species will become more manageable or disappear altogether.

Ecologist 2

     The best way to control the vegetation would be to physically cut and remove it from the biome. Seasonal cuttings would minimize the population and decrease reproductive success. Furthermore, any nutrients contained in the decomposing plant litter would be removed with the waste. Therefore, after several sweeps the plants would be removed altogether.

A new study reveals that plants are better removed by pulling them out by the roots rather than using conventional herbicides. Which scientist's views are comparable to the results of this study?

Possible Answers:

Ecologist 2

Neither

Both 

Ecologist 1

Correct answer:

Ecologist 2

Explanation:

This data supports Ecologist 2's stance. This scientist believes that the best way to control the problem is to physically cut out the plant rather than introducing chemical mediators. Furthermore, Ecologist 1's view states nothing of physical measures to remove the invasive species.

Example Question #639 : Biology

     Invasive species lack the natural competitors in a given area to properly regulate population growth and development. Myriophyllum spicatum is a Eurasian milfoil. It was first used in the United States as an aesthetic for aquatic fish tanks. Later, it was accidentally introduced into local ponds and lakes where it became a dominant invasive species and has began to choke out native and naturally occurring plant life. To make matters worse, phosphorus-rich fertilizers and cleaners have contaminated many freshwater biomes due to runoff and pollution. As a result, many standing freshwater pools contain heavy amounts of phosphorus. These species readily utilize the phosphorus and have become nearly unmanageable. Two ecologists express their views on how to control the invasive population.

Ecologist 1

     The best way to control the problem is to limit the nutrients in the biome. If the nutrients are controlled then the plants will be unable to grow and flourish. After several generations, the nutrients will be depleted and the plant species will become more manageable or disappear altogether.

Ecologist 2

     The best way to control the vegetation would be to physically cut and remove it from the biome. Seasonal cuttings would minimize the population and decrease reproductive success. Furthermore, any nutrients contained in the decomposing plant litter would be removed with the waste. Therefore, after several sweeps the plants would be removed altogether.

Scientists begin to study the lake in the early spring. They notice that many geese surround the lake. The geese's excrement is high in phosphorus content. The scientists notice that as the geese population declines in the fall so does the biomass of the invasive species. How would Ecologist 1 explain this phenomenon?

Possible Answers:

Ecologist 1 would hypothesize that the birds leave with the shorter days of fall and winter and that the shorter doses of sunlight decreases plant biomass and fitness.

Ecologist 1 would hypothesize that the phosphorus content provided by the birds directly correlates to plant biomass because the invasive species utilize it for growth and development.

Ecologist 1 would hypothesize that the fish in the lake gorge on the plant life in the absence of their geese competitors.

Ecologist 1 would hypothesize that the colder weather leads to a decrease in plant populations and biomass.

Correct answer:

Ecologist 1 would hypothesize that the phosphorus content provided by the birds directly correlates to plant biomass because the invasive species utilize it for growth and development.

Explanation:

Ecologist 1 would hypothesize that the phosphorus content provided by the birds directly correlates to plant biomass because the invasive species utilize it for growth and development.

Example Question #640 : Biology

     Invasive species lack the natural competitors in a given area to properly regulate population growth and development. Myriophyllum spicatum is a Eurasian milfoil. It was first used in the United States as an aesthetic for aquatic fish tanks. Later, it was accidentally introduced into local ponds and lakes where it became a dominant invasive species and has began to choke out native and naturally occurring plant life. To make matters worse, phosphorus-rich fertilizers and cleaners have contaminated many freshwater biomes due to runoff and pollution. As a result, many standing freshwater pools contain heavy amounts of phosphorus. These species readily utilize the phosphorus and have become nearly unmanageable. Two ecologists express their views on how to control the invasive population.

Ecologist 1

     The best way to control the problem is to limit the nutrients in the biome. If the nutrients are controlled then the plants will be unable to grow and flourish. After several generations, the nutrients will be depleted and the plant species will become more manageable or disappear altogether.

Ecologist 2

     The best way to control the vegetation would be to physically cut and remove it from the biome. Seasonal cuttings would minimize the population and decrease reproductive success. Furthermore, any nutrients contained in the decomposing plant litter would be removed with the waste. Therefore, after several sweeps the plants would be removed altogether.

Careful observation has revealed that the invasive species' biomass is greatest in May after heavy rainfalls. How would Ecologist 1 explain this phenomenon?

Possible Answers:

May indicates the start of spring turnover which releases nutrients to the plants.

May weather increases the amount of soil bound phosphorus for the plant to utilize.

May commences the start of spring and cues the plant to gain biomass.

May is the height of the planting season and the phosphorus found in cheaper fertilizers runs into the lake during heavy rains.

Correct answer:

May is the height of the planting season and the phosphorus found in cheaper fertilizers runs into the lake during heavy rains.

Explanation:

May is the height of the planting season and the phosphorus found in cheaper fertilizers runs into the lake during heavy rains.

The passage reveals that the lake is a biological sink that has been detrimentally affected by runoff. Ecologist 1's viewpoint on the issue deals with controlling nutrient and chemical runoff into the biome. Furthermore, the weather, soil bound phosphorus, and spring turnover are natural occurences and not directly related to the issues of pollution and invasive plant growth.

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