ACT Science : ACT Science

Study concepts, example questions & explanations for ACT Science

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Example Questions

Example Question #111 : How To Find Research Summary In Biology

Two students present their ideas on species and populations, as well as their views on how species physically change over time. They also discuss phenomena that support their different models.

 

Student A

Within a population of individuals of a given species, there is little variation. All individuals are able to physically transform in ways that suit their needs. Physical change, such as the lengthening of a giraffe's neck, occurs over long periods of time because of a desire to modify one's characteristics. For example, in the past, giraffes likely found themselves surrounded by tall trees, and therefore had difficulty obtaining food on the tops of trees. In order to survive, they stretched their necks gradually to elongate them. Offspring inherited slightly longer necks, and, over time, giraffes developed unusually long necks. The fossil record indicates that giraffes in prehistoric times had significantly shorter necks compared to modern giraffes.

 

Student B

Any sizable population of individuals of a given species will contain noticeable variation. The physical characteristics of an individual are fixed. In a prehistoric population of hawks, for example, some individuals had powerful vision while others had weaker vision. The hawks competed with one another for food, and individuals with sharper vision were better equipped to spot small prey such as mice (their main source of food). Hawks with poorer vision, by contrast, had difficulty spotting prey and perished from starvation. The individuals with sharp vision passed on this desirable trait to their offspring, and, over time, hawks developed very keen eyesight. Analysis of the DNA from a prehistoric population of hawks has revealed significant differences between individuals in the genes that control eyesight.

 

Which of the following findings, if true, could be used to counter the argument of Student B?

Possible Answers:

Hawks of a prehistoric population did not compete with other species of birds

Within a prehistoric population of hawks, competition was virtually nonexistent

Within a prehistoric population of hawks, competition was high

Within a modern population of hawks, there is moderate competition

Correct answer:

Within a prehistoric population of hawks, competition was virtually nonexistent

Explanation:

Student B argues that competition within prehistoric populations of hawks led to the propagation of powerful vision in hawks. Evidence that there was almost no competition in a prehistoric population of hawks would seriously weaken the argument of Student B.

Example Question #111 : How To Find Research Summary In Biology

Two students present their ideas on species and populations, as well as their views on how species physically change over time. They also discuss phenomena that support their different models.

 

Student A

Within a population of individuals of a given species, there is little variation. All individuals are able to physically transform in ways that suit their needs. Physical change, such as the lengthening of a giraffe's neck, occurs over long periods of time because of a desire to modify one's characteristics. For example, in the past, giraffes likely found themselves surrounded by tall trees, and therefore had difficulty obtaining food on the tops of trees. In order to survive, they stretched their necks gradually to elongate them. Offspring inherited slightly longer necks, and, over time, giraffes developed unusually long necks. The fossil record indicates that giraffes in prehistoric times had significantly shorter necks compared to modern giraffes.

 

Student B

Any sizable population of individuals of a given species will contain noticeable variation. The physical characteristics of an individual are fixed. In a prehistoric population of hawks, for example, some individuals had powerful vision while others had weaker vision. The hawks competed with one another for food, and individuals with sharper vision were better equipped to spot small prey such as mice (their main source of food). Hawks with poorer vision, by contrast, had difficulty spotting prey and perished from starvation. The individuals with sharp vision passed on this desirable trait to their offspring, and, over time, hawks developed very keen eyesight. Analysis of the DNA from a prehistoric population of hawks has revealed significant differences between individuals in the genes that control eyesight.

 

Suppose it were discovered that a prehistoric population of hawks relied primarily on the carcasses of large animals for food. Would this discovery strengthen the argument of Student B?

Possible Answers:

Yes, because Student B argues that prehistoric hawks relied on eyesight to spot large prey.

Yes, because Student B argues that prehistoric hawks relied on eyesight to spot small prey.

No, because Student B argues that prehistoric hawks relied on eyesight to spot large prey.

No, because Student B argues that prehistoric hawks relied on eyesight to spot small prey.

Correct answer:

No, because Student B argues that prehistoric hawks relied on eyesight to spot small prey.

Explanation:

Student B argues that prehistoric hawks relied on eyesight to spot small prey. If it were discovered that these hawks primarily fed on carcasses of large animals and not small prey, the argument of Student B would be weakened.

Example Question #113 : How To Find Research Summary In Biology

Two students present their ideas on species and populations, as well as their views on how species physically change over time. They also discuss phenomena that support their different models.

 

Student A

Within a population of individuals of a given species, there is little variation. All individuals are able to physically transform in ways that suit their needs. Physical change, such as the lengthening of a giraffe's neck, occurs over long periods of time because of a desire to modify one's characteristics. For example, in the past, giraffes likely found themselves surrounded by tall trees, and therefore had difficulty obtaining food on the tops of trees. In order to survive, they stretched their necks gradually to elongate them. Offspring inherited slightly longer necks, and, over time, giraffes developed unusually long necks. The fossil record indicates that giraffes in prehistoric times had significantly shorter necks compared to modern giraffes.

 

Student B

Any sizable population of individuals of a given species will contain noticeable variation. The physical characteristics of an individual are fixed. In a prehistoric population of hawks, for example, some individuals had powerful vision while others had weaker vision. The hawks competed with one another for food, and individuals with sharper vision were better equipped to spot small prey such as mice (their main source of food). Hawks with poorer vision, by contrast, had difficulty spotting prey and perished from starvation. The individuals with sharp vision passed on this desirable trait to their offspring, and, over time, hawks developed very keen eyesight. Analysis of the DNA from a prehistoric population of hawks has revealed significant differences between individuals in the genes that control eyesight.

 

Which of the following best explains why Student A mentioned the fossil record?

Possible Answers:

The fossil record serves as evidence of the lack of variation within a prehistoric population of giraffes

The fossil record serves as evidence of the significant variation within a prehistoric population of giraffes

The fossil record serves as evidence of the change in giraffe neck length over time

The fossil record serves as evidence of the competition between giraffes of a prehistoric population

Correct answer:

The fossil record serves as evidence of the change in giraffe neck length over time

Explanation:

Student A mentions the fossil record to support the idea that giraffe neck length has changed over time. He/she argues that the fossil record shows how giraffes in prehistoric times had much shorter necks compared to modern giraffes.

Example Question #114 : How To Find Research Summary In Biology

Two students present their ideas on species and populations, as well as their views on how species physically change over time. They also discuss phenomena that support their different models.

 

Student A

Within a population of individuals of a given species, there is little variation. All individuals are able to physically transform in ways that suit their needs. Physical change, such as the lengthening of a giraffe's neck, occurs over long periods of time because of a desire to modify one's characteristics. For example, in the past, giraffes likely found themselves surrounded by tall trees, and therefore had difficulty obtaining food on the tops of trees. In order to survive, they stretched their necks gradually to elongate them. Offspring inherited slightly longer necks, and, over time, giraffes developed unusually long necks. The fossil record indicates that giraffes in prehistoric times had significantly shorter necks compared to modern giraffes.

 

Student B

Any sizable population of individuals of a given species will contain noticeable variation. The physical characteristics of an individual are fixed. In a prehistoric population of hawks, for example, some individuals had powerful vision while others had weaker vision. The hawks competed with one another for food, and individuals with sharper vision were better equipped to spot small prey such as mice (their main source of food). Hawks with poorer vision, by contrast, had difficulty spotting prey and perished from starvation. The individuals with sharp vision passed on this desirable trait to their offspring, and, over time, hawks developed very keen eyesight. Analysis of the DNA from a prehistoric population of hawks has revealed significant differences between individuals in the genes that control eyesight.

 

Both students would likely agree that significant changes in species occur over __________.

Possible Answers:

a couple of years

a single generation

many generations

several weeks

Correct answer:

many generations

Explanation:

Both students refer to prehistoric populations of species, suggesting that change in species occurs over many generations.

Example Question #115 : How To Find Research Summary In Biology

Elena is conducting an experiment to determine the effect of a new drug, norzapam, that is meant to help diabetic patients produce insulin naturally. She has four test subjects, all with type 1 diabetes, and all of whom continued to take fast-acting insulin as needed but ceased taking long-acting insulin. Two patients received the drug and two received a placebo. Over a period of ten months Elena measured her patients’ insulin levels each day (measured in International Units) and averaged them for each month. She also asked each patient to walk for as long as they could after taking the drug before their blood sugar dropped too low to continue. Her results from the experiment are shown in the given tables.

Patient 1: Drug received

Patient 1 is a 45 year-old male who is overweight and leads a sedentary lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

50

15

2

52

18

3

54

20

4

60

20

5

64

22

6

70

25

7

78

28

8

86

33

9

98

38

10

103

40

 

Patient 2: Drug received

Patient 2 is a 23 year-old female of healthy weight who leads an active lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

50

30

2

55

38

3

59

42

4

68

47

5

75

55

6

83

60

7

90

68

8

97

70

9

105

72

10

112

75

 

Patient 3: No drug

Patient 3 is a 60 year-old female who is overweight and leads a moderately active lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

50

25

2

51

25

3

53

28

4

51

25

5

53

28

6

55

30

7

53

28

8

65

33

9

51

25

10

50

25

 

Patient 4: No Drug

Patient 4 is a 28 year-old male of healthy weight who leads very active lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

60

45

2

65

48

3

68

50

4

68

50

5

70

55

6

71

56

7

68

52

8

69

55

9

79

65

10

80

65

Is there enough evidence to prove the drug causes insulin levels to be raised?

Possible Answers:

No, there were not enough men sampled

Yes, the results are consistent with this conclusion

No, more people should have been sampled

No, there was no control group

Correct answer:

No, more people should have been sampled

Explanation:

To prove causation one needs to experiment with a large, randomized sample of people. While this could have been a causal experiment, Elena lacked that. There is no evidence that suggests she randomly sampled people for her experiment. Also, there are too many possible confounding variables that she has not addressed. 

Example Question #116 : How To Find Research Summary In Biology

Elena is conducting an experiment to determine the effect of a new drug, norzapam, that is meant to help diabetic patients produce insulin naturally. She has four test subjects, all with type 1 diabetes, and all of whom continued to take fast-acting insulin as needed but ceased taking long-acting insulin. Two patients received the drug and two received a placebo. Over a period of ten months Elena measured her patients’ insulin levels each day (measured in International Units) and averaged them for each month. She also asked each patient to walk for as long as they could after taking the drug before their blood sugar dropped too low to continue. Her results from the experiment are shown in the given tables.

Patient 1: Drug received

Patient 1 is a 45 year-old male who is overweight and leads a sedentary lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

50

15

2

52

18

3

54

20

4

60

20

5

64

22

6

70

25

7

78

28

8

86

33

9

98

38

10

103

40

 

Patient 2: Drug received

Patient 2 is a 23 year-old female of healthy weight who leads an active lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

50

30

2

55

38

3

59

42

4

68

47

5

75

55

6

83

60

7

90

68

8

97

70

9

105

72

10

112

75

 

Patient 3: No drug

Patient 3 is a 60 year-old female who is overweight and leads a moderately active lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

50

25

2

51

25

3

53

28

4

51

25

5

53

28

6

55

30

7

53

28

8

65

33

9

51

25

10

50

25

 

Patient 4: No Drug

Patient 4 is a 28 year-old male of healthy weight who leads very active lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

60

45

2

65

48

3

68

50

4

68

50

5

70

55

6

71

56

7

68

52

8

69

55

9

79

65

10

80

65

What could have caused the dip in insulin levels for patient 3 during months 9 and 10?

Possible Answers:

A divorce

A change in walking habits

A change in eating habits

A medical concern

Correct answer:

A medical concern

Explanation:

We know patient 3 didn't change her walking habits as we have evidence she walked a number of minutes each day. We have no data on eating habits, nor personal life, such as divorce.. The only likely possibility is that she had a medical concern that briefly change her biology and affected insulin levels. 

Example Question #251 : Act Science

Elena is conducting an experiment to determine the effect of a new drug, norzapam, that is meant to help diabetic patients produce insulin naturally. She has four test subjects, all with type 1 diabetes, and all of whom continued to take fast-acting insulin as needed but ceased taking long-acting insulin. Two patients received the drug and two received a placebo. Over a period of ten months Elena measured her patients’ insulin levels each day (measured in International Units) and averaged them for each month. She also asked each patient to walk for as long as they could after taking the drug before their blood sugar dropped too low to continue. Her results from the experiment are shown in the given tables.

Patient 1: Drug received

Patient 1 is a 45 year-old male who is overweight and leads a sedentary lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

50

15

2

52

18

3

54

20

4

60

20

5

64

22

6

70

25

7

78

28

8

86

33

9

98

38

10

103

40

 

Patient 2: Drug received

Patient 2 is a 23 year-old female of healthy weight who leads an active lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

50

30

2

55

38

3

59

42

4

68

47

5

75

55

6

83

60

7

90

68

8

97

70

9

105

72

10

112

75

 

Patient 3: No drug

Patient 3 is a 60 year-old female who is overweight and leads a moderately active lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

50

25

2

51

25

3

53

28

4

51

25

5

53

28

6

55

30

7

53

28

8

65

33

9

51

25

10

50

25

 

Patient 4: No Drug

Patient 4 is a 28 year-old male of healthy weight who leads very active lifestyle.

Month

Insulin level (IU)

Length of Walk (min)

1

60

45

2

65

48

3

68

50

4

68

50

5

70

55

6

71

56

7

68

52

8

69

55

9

79

65

10

80

65

A fifth patient, patient 5 is added to the study. She is a 25 year-old female of health weight who leads an active lifestyle. What would her insulin levels likely have been?

Possible Answers:

Low, like that of patient 3

Low, like that of patient 4

High, like that of patient 1

High, like that of patient 2

Correct answer:

High, like that of patient 2

Explanation:

Note that the patient is young fit and active. There are two others like her, patients 2 and 4. Both have comparatively high insulin levels, though patient 2's remain low due to receiving the placebo. Therefore this new patient is most likely going to have insulin levels like patient 1, who is both fit as well as receives the drug. 

Example Question #251 : Act Science

Researchers have recorded data in four different regions, Region A, Region B, Region C and Region D. In these regions, the researchers recorded the height, diameter and the approximate age of the tallest redwood. The researchers want to use this data to learn more amount redwoods and their respective regions.

Act 2

If each of the measured trees were located in a forest in their respective regions, which region has the oldest forest? 

Possible Answers:

Region C

Region B

Region D

Region A

Correct answer:

Region C

Explanation:

In the data given, the older the tree is the taller that the tree is. In other words there is a direct relationship between the height of the tree and its age. Since all of the trees measured are the tallest trees in their regions, it can be implied that the measured trees are the oldest tree in their respective regions. The oldest tree that was measured was in Region C and therefore Region C is the oldest forest. 

Example Question #122 : How To Find Research Summary In Biology

Two scientists are examining the fragmented skeletal remains of an unidentified person. To begin work on identification, they must start by determining several characteristics about the individual, including sex. When determining sex, a measurement index can be used. Measurements can be taken from various points on the skeleton, such as the scapula or the femur, which then correspond to documented averages for different sexes, which vary with ancestry. In this individual of Latin American ancestry, the scapular breadth has measured 22.0cm, which is the only true sex-determining measurement that can be taken from these remains. In their reference books, the scientists find that this measurement in Latin American females ranges from 18.0-22.0cm and 22.0-24.0cm for Latin American males. Both scientists make a case using other supporting evidence as to which sex this unidentified individual may be.

Scientist 1

Sex can be clearly defined through context clues. Items found with the body and the way the body was found can both be used to determine the sex of the individual in cases such as this which lack other sex-determining measurements. The remains were found with small tennis shoes (size 8), which would generally be indicative of a female. The bag found with the body contained waterlogged copies of several popular magazines, as well as a broken cell phone, nail clippers, and a tube of lip balm. These items are generally more associated with items commonly carried by and used by female individuals rather than males. Because of abundant context clues, this individual can be determined to be female despite ambiguous measurements. 

Scientist 2

Clues about the sex of the individual can come from multiple sources. Context clues, such as the items found with the body, can help. The small shoes and stereotypically female-associated objects found with the remains can give an indication that the person must likely have been female. Another way to help determine sex is through estimated overall stature of the person – men are generally larger and more robustly built than females of the same ancestry. A rough estimation of stature of this individual would indicate that they were about 5’10” tall and heavily muscled. While not impossible for a female, this is a build that is much more likely to belong to a male individual. Though the context clues seem to point toward a female, the stature of the individual strongly suggests male.

With which of the following statements would both scientists likely agree?

Possible Answers:

Multiple methods of determination should always be used.

The size of shoes can be used to definitely determine the sex of a person.

Measurements might be wrong.

Context clues can be useful in determining the sex of an individual.

Correct answer:

Context clues can be useful in determining the sex of an individual.

Explanation:

Both scientists make mention of the use of context clues in their theories of sex determination.

Example Question #122 : How To Find Research Summary In Biology

Two scientists are examining the fragmented skeletal remains of an unidentified person. To begin work on identification, they must start by determining several characteristics about the individual, including sex. When determining sex, a measurement index can be used. Measurements can be taken from various points on the skeleton, such as the scapula or the femur, which then correspond to documented averages for different sexes, which vary with ancestry. In this individual of Latin American ancestry, the scapular breadth has measured 22.0cm, which is the only true sex-determining measurement that can be taken from these remains. In their reference books, the scientists find that this measurement in Latin American females ranges from 18.0-22.0cm and 22.0-24.0cm for Latin American males. Both scientists make a case using other supporting evidence as to which sex this unidentified individual may be.

Scientist 1

Sex can be clearly defined through context clues. Items found with the body and the way the body was found can both be used to determine the sex of the individual in cases such as this which lack other sex-determining measurements. The remains were found with small tennis shoes (size 8), which would generally be indicative of a female. The bag found with the body contained waterlogged copies of several popular magazines, as well as a broken cell phone, nail clippers, and a tube of lip balm. These items are generally more associated with items commonly carried by and used by female individuals rather than males. Because of abundant context clues, this individual can be determined to be female despite ambiguous measurements. 

Scientist 2

Clues about the sex of the individual can come from multiple sources. Context clues, such as the items found with the body, can help. The small shoes and stereotypically female-associated objects found with the remains can give an indication that the person must likely have been female. Another way to help determine sex is through estimated overall stature of the person – men are generally larger and more robustly built than females of the same ancestry. A rough estimation of stature of this individual would indicate that they were about 5’10” tall and heavily muscled. While not impossible for a female, this is a build that is much more likely to belong to a male individual. Though the context clues seem to point toward a female, the stature of the individual strongly suggests male.

Scientist 1 claims that the items found with the body (small shoes, lip balm, magazines, nail clippers) are stereotypically female. If the body was found with stereotypically male items (a knife, rope, large shoes), how might Scientist 1's conclusion change?

Possible Answers:

Scientist 1 would conclude that the individual was female

Scientist 1 would conclude that there might have been a second individual

Scientist would conclude that there was not enough evidence to determine the sex of the individual

Scientist 1 would conclude that the individual was male

Correct answer:

Scientist 1 would conclude that the individual was male

Explanation:

Scientist 1 relies on the type of context clues to determine sex. If the items found with the body (context clues) were typically male items, then Scientist 1 would likely claim the individual to be male.

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