ACT Science : How to find research summary in biology

Study concepts, example questions & explanations for ACT Science

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Example Questions

Example Question #131 : How To Find Research Summary In Biology

Act science practice set 1 q 1 page 001

According to Survey 1 and Survey 2, which variable tested by the botanist had the greatest impact on average tree height?

Possible Answers:

All of these variables had an equal impact

Light level

Ground soil moisture

Insect abundance

Correct answer:

Light level

Explanation:

It is clear from Table 1 and Table 2 that light level had the largest impact on average tree height. Following across many of the table rows shows that light level has a large impact, up to 7.5', on average tree height from Very Dim to Very Bright, where the other two variables only have at most a 4.3' impact.

Example Question #132 : How To Find Research Summary In Biology

Act science practice set 1 q 1 page 001

Based on both Survey 1 and Survey 2, what can the botanist conclude about what will factors will encourage maximum tree growth, considering that the forest is mostly average and bright light level areas?

Possible Answers:

Keeping up soil moisture is more significant than keeping down insect abundance

There is not a difference in height between Average and Bright light level areas

The trees grow the same height no matter what factors are involved

Insects, on average, are the most detrimental factor to tree growth

Correct answer:

Keeping up soil moisture is more significant than keeping down insect abundance

Explanation:

The correct answer is that ground soil moisture is more significant than insect abundance. If you compare the average and bright light level columns in Table 1 and Table 2, you can see that there is much more of a difference in height by ground soil moisture than insect abundance.

Example Question #133 : How To Find Research Summary In Biology

Act science practice set 1 q 2 page 001

Considering that the normal human body temperature is 37 degrees Celsius and the normal body pH is 7.4, what can the researcher conclude about the effectiveness of this antibiotic in humans?

Possible Answers:

These variables are not represented in the scientist's experiments

This antibiotic is most effective at a temperature of 37 degrees C, but not at a pH of 7.4

This antibiotic is at its most effective conditions

This antibiotic is at its least effective conditions

Correct answer:

This antibiotic is at its least effective conditions

Explanation:

The correct answer is that the antibiotic is at its least effective at a temperature of 37 degrees Celsius and a pH of 7.4, although there is not a great deal of difference. This could be significant for dosages of this antibiotic, however.

Example Question #134 : How To Find Research Summary In Biology

Act science practice set 1 q 2 page 001

Which statement best describes the outcome of the experiments in this study?

Possible Answers:

This antibiotic is at least  effective at doses of  or higher

Temperature changes have more of an effect on this antibiotic's effectiveness than pH changes

pH changes have more of an effect on this antibiotic's effectiveness than temperature changes

This antibiotic will only effectively destroy bacteria at a temperature of  degrees Celsius or lower

Correct answer:

This antibiotic is at least  effective at doses of  or higher

Explanation:

The correct answer is that this antibiotic is at least 90% effective at all doses greater than . No matter what the value of the two variables (experimental temperature and experimental pH), the antibiotic kills greater than 90% of the bacteria in the experiment when it is at least .

Example Question #135 : How To Find Research Summary In Biology

Scientists want to see how any athlete's heart health is different from others. The scientists monitor four individual's (A, B, C and D) heart rates during sleep, rest and intense exercise. Only one athlete was tested and the data was recorded in the table below in heart beats per minute.

Act 1

Which individual has the best overall fitness? 

Possible Answers:

Individual A

Cannot be determined from the given information

Individual B

Individual D

Individual C

Correct answer:

Cannot be determined from the given information

Explanation:

The experiment that was performed focused on monitoring the heart rates of individuals. This can be used as an indicator of heart health, but does not tell any information about the rest of the body. The answer cannot be determined since no tests were done on muscle fitness, body fat, respiratory tract, etc. There are many systems that would have to be tested for overall health other than heart rate. 

Example Question #136 : How To Find Research Summary In Biology

Botulism is a rare disease caused by the botulinum toxin produced and secreted by Clostridium botulinum. Botulism causes muscle weakness and in severe cases can inhibit the muscles of respiration and lead to respiratory failure and even death. The exotoxin produced by Clostridium botulinum causes damage to its host by inhibiting of the release of the chemical messenger acetylcholine. Acetylcholine is a neurotransmitter, meaning it is responsible for enabling communication between a nerve cell and other cells. 

Experiment A

Scientists conducting a study on the lethality of the botulinum toxin are looking at the effect of acidification on the toxin’s potency. They design a study in mice to identify the minimal lethal dose of botulinum toxin. The scientists believe acidification will reduce the minimal lethal dose. The findings from their study are below:

Min lethal

Experiment B

Scientists also assessed the relationship between acidification and the incubation period. The incubation period was defined as the time between exposure to the toxin and the onset of symptoms. 

Incub

Data and concepts from: Bronfenbrenner, J. & Schlesinger M.J. (1922). Some of the factors contributing to toxicity of botulinus toxin by mouth. JAMA78(20), 1519-1521.

Which of the following is best summarizes the scientists' hypothesis for Experiment A?

Possible Answers:

A lower pH will be associated with greater acidification.

A higher minimal lethal dose of botulinum toxin will result in greater acidification.

Greater acidification will result in a lower minimal lethal dose of botulinum toxin.

A basic pH will results in a lower minimal lethal dose of botulinum toxin.

Correct answer:

Greater acidification will result in a lower minimal lethal dose of botulinum toxin.

Explanation:

As the pH decreases a substance becomes more acidic. Thus, as the chart shows the lower the pH, the smaller the minimal lethal dose. At an acidic pH of 4.0 the minimal lethal dose is  which is much smaller than  when the pH is a neutral 7.0. Thus, greater acidification will result in a lower minimal lethal dose of botulinum toxin.

Example Question #131 : How To Find Research Summary In Biology

A mycologist, a scientist specializing in the study of mushrooms, wants to compare the growth of three types of mushroom (A, B, and C) on varying growth substrates. He is also curious how light will affect the growth of each of the samples. He designs an experiment where each variety of mushroom will be grown on manure, wood chips, or rice flour and includes identical trials with and without light. He records the mass of the mushrooms produced after 14 days of fruiting and finds the following results:

Mass of Mushrooms after 14 days of Fruiting (grams)
  No Light Exposure Exposed to Light
Growth Substrate Mushroom A Mushroom B Mushroom C Mushroom A Mushroom B Mushroom C
Manure 14.2 6.2 12.2 7.8 6.1 2.8
Woodchips 9.1 12.1 8.8 5.3 11.9 2.1
Rice Flour 2.4 9.3 19.4 1.1 9.4 19.3

Based on this data, describe the growth conditions for Mushroom strain A that would lead to the largest mushrooms produced.

Possible Answers:

Growth on woodchips with light exposure.

Growth on woodchips without light exposure.

Growth on manure with no light exposure.

Growth on rice flour without light exposure.

Growth on manure with light exposure.

Correct answer:

Growth on manure with no light exposure.

Explanation:

Strain A produced the mushrooms with the greatest mass when not exposed to light and grown on manure, therefore these conditions would produce the largest mushrooms in the future as well.

Example Question #138 : How To Find Research Summary In Biology

A botanist is trying to see the effects of temperature on a certain plant species. She prepares four identical plots of soil and runs a heating element through the soil so she can vary the temperature of each plot. After one month she harvests all of the plant biomass and records the temperature of each plot along with the biomass collected. The data are given in the table below.

Planttable1

Based on the data in the table, which of the following best describes the preferred climate for this plant?

Possible Answers:

Cool climate

Hot climate

Warm climate

Based on the data there is no preference

Moderate climate

Correct answer:

Moderate climate

Explanation:

The data show that the largest plant biomass is gathered at . This would suggest that the plant prefers moderate climates. Notice that at  the biomass is lower, and at the highest temperature it is lowest. So we know it shouldn't prefer a cool or warm climate only. 

This question assumes that you take plant biomass as a proxy for the plant's preference. Biomass describes how much plant there is. The more plant, the more the plant has grown, i.e. the better the plant does in those conditions.

Example Question #139 : How To Find Research Summary In Biology

A botanist is trying to see the effects of temperature on a certain plant species. She prepares four identical plots of soil and runs a heating element through the soil so she can vary the temperature of each plot. After one month she harvests all of the plant biomass and records the temperature of each plot along with the biomass collected. The data are given in the table below.

Planttable1

The botanist then consults the following information that lists the range of temperatures at which the species may be found growing in the wild. 

Species

Based on the data above, which of the following is most likely to be the species studied by the experimenter?

Possible Answers:

Z

Y

W

X

W or Z

Correct answer:

X

Explanation:

Based on the first experiment we know that the plant definitely grows in temperatures ranging from . So any species that cannot be found outside of this temperature range is not likely to be a match. This leaves only one answer, species X.

Example Question #140 : How To Find Research Summary In Biology

The Millikin oil drop experiment is among the most important experiments in the history of science. It was used to determine one of the fundamental constants of the universe, the charge on the electron. For his work, Robert Millikin won the Nobel Prize in Physics in 1923.

Millikin used an experimental setup as follows in Figure 1. He opened a chamber of oil into an adjacent uniform electric field. The oil droplets sank into the electric field once the trap door opened, but were then immediately suspended by the forces of electricity present in the field.

Figure 1:

Millikin

By determining how much force was needed to exactly counteract the gravity pulling the oil droplet down, Millikin was able to determine the force of electricity. This is depicted in Figure 2.

Using this information, he was able to calculate the exact charge on an electron. By changing some conditions, such as creating a vacuum in the apparatus, the experiment can be modified. 

Figure 2:

Millikin_drop

When the drop is suspended perfectly, the total forces up equal the total forces down. Because Millikin knew the electric field in the apparatus, the force of air resistance, the mass of the drop, and the acceleration due to gravity, he was able to solve the following equation: 

Table 1 summarizes the electric charge found on oil drops in suspension. Millikin correctly concluded that the calculated charges must all be multiples of the fundamental charge of the electron. A hypothetical oil drop contains some net charge due to lost electrons, and this net charge cannot be smaller than the charge on a single electron.

Table 1: 

Trial #

Electric Charge Calculated in Coulombs (C)

Vacuum Used?

1

1.602176487 x 10-8

No

2

1.602176487 x 10-2

Yes

3

1.602176487 x 10-6

No

4

1.602176487 x 10-4

Yes

 

For an electron in suspension within a vacuum, under the influence of an electric field:

Possible Answers:

the electric force is unequal in magnitude and in the same direction with the force of gravity.

the electric force is equal in magnitude and opposite in direction to the force of gravity.

the electric force is unequal in magnitude and opposite in direction to the force of gravity.

the electric force is equal in magnitude and in the same direction with the force of gravity.

Correct answer:

the electric force is equal in magnitude and opposite in direction to the force of gravity.

Explanation:

The oil drop suspended in the electric field is experiencing gravitational force pulling the drop down, and electric force holding it up in suspension. Because it is stationary, these forces are exactly equal in magnitude, and opposite in direction.

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