ACT Science : How to find synthesis of data in biology

Study concepts, example questions & explanations for ACT Science

varsity tutors app store varsity tutors android store varsity tutors amazon store varsity tutors ibooks store

Example Questions

Example Question #452 : Biology

Lynx_and_hare

Predator-prey relationships and mechanics are important tools for understanding the ecology of environments. Population cycles were first recorded in Canadian forests by fur trappers. Species interactions are important indicators of the health and economy of a natural environment. A twelve-year study of northern Canada revealed that snowshoe hares and lynxes share highly synchronized and predictable cycles. The lynx's predator populations mimic and mirrors that of their prey, the snowshoe hare. Two scientists express their views on these population patterns below.

Scientist 1

     The observed relationship is best explained by predator-prey relationships and competition for resources. Consumer-resource interactions fluctuate independently of variation within the environment.

Scientist 2

     The observed relationship is produced by environmental changes. Fluctuations in weather patterns and resources manipulate observed predator-prey relationships.

Snowfall

The table above represents recorded data on snowfall. Which scientist's view does this data support?

Possible Answers:

Neither

Scientist 2

Scientist 1

Both

Correct answer:

Scientist 2

Explanation:

This information supports Scientist 2's view. The pattern of snowfall follows the inverse pattern of both species' population growths. Years of heavy snow coincide with smaller populations while periods of low snowfall coincide with larger population numbers. In other words, the environment affects the the species population.

Example Question #453 : Biology

Population growth models are used to compile data and determine whether a population is in a state of growth or decline. The -axis of each of the following graphs of different population models represents the age of the population. Bars then represent the percentage of the population that lies in the given range, which is presented on the -axis of each graph; furthermore, the graphs are broken into male and female sides. A population that is in a state of decline will have a higher percentage of aging and therefore non-reproducing individuals. A population that is in a state of growth will have a higher percentage of younger individuals ready to reproduce and add to the numbers of the population. A population is in a steady state if the aging and young populations share similar percentages.

Growth_models

Which model is in a state of population growth?

Possible Answers:

Model 2

Model 1

None of the models represents population growth.

Model 3

Correct answer:

Model 1

Explanation:

Model 1 is the correct answer, because the base of the model possesses a higher percentage of the population than the top of the model. The individuals at the base of the model are younger and thus likely to produce viable offspring and increase the number of individuals in the population.

Example Question #454 : Biology

Population growth models are used to compile data and determine whether a population is in a state of growth or decline. The -axis of each of the following graphs of different population models represents the age of the population. Bars then represent the percentage of the population that lies in the given range, which is presented on the -axis of each graph; furthermore, the graphs are broken into male and female sides. A population that is in a state of decline will have a higher percentage of aging and therefore non-reproducing individuals. A population that is in a state of growth will have a higher percentage of younger individuals ready to reproduce and add to the numbers of the population. A population is in a steady state if the aging and young populations share similar percentages.

Growth_models

Which model is in a state of population decline?

Possible Answers:

Model 3

None of the models represents population decline.

Model 2

Model 1

Correct answer:

Model 2

Explanation:

Model 2 is the correct choice because it has a broader top section than base section. This indicates that much of the population is elderly. They are likely to die sooner than other members of the population and less likely to reproduce. This indicates that more members will pass on and fewer members will replace them within the population, decreasing its numbers.

Example Question #455 : Biology

Population growth models are used to compile data and determine whether a population is in a state of growth or decline. The -axis of each of the following graphs of different population models represents the age of the population. Bars then represent the percentage of the population that lies in the given range, which is presented on the -axis of each graph; furthermore, the graphs are broken into male and female sides. A population that is in a state of decline will have a higher percentage of aging and therefore non-reproducing individuals. A population that is in a state of growth will have a higher percentage of younger individuals ready to reproduce and add to the numbers of the population. A population is in a steady state if the aging and young populations share similar percentages.

Growth_models

Consider a hypothetical population that has a distribution like that shown in Model 3. If many of the female members of this population became unable to reproduce, what would one expect to happen to this population in the future?

Possible Answers:

The population would not change in size.

The population would grow.

The population would decline and then grow.

The population would decline.

Correct answer:

The population would decline.

Explanation:

The population would decline. As members of this hypothetical population passed away, the younger generations would be unable to reproduce at the same rate to replace them; therefore, one would logically expect the size of the population to decrease over time.

Example Question #451 : Act Science

Population growth models are used to compile data and determine whether a population is in a state of growth or decline. The -axis of each of the following graphs of different population models represents the age of the population. Bars then represent the percentage of the population that lies in the given range, which is presented on the -axis of each graph; furthermore, the graphs are broken into male and female sides. A population that is in a state of decline will have a higher percentage of aging and therefore non-reproducing individuals. A population that is in a state of growth will have a higher percentage of younger individuals ready to reproduce and add to the numbers of the population. A population is in a steady state if the aging and young populations share similar percentages.

Growth_models

Consider hypothetical populations with demographics like those depicted in each of the models. Over multiple generations, which population would be most drastically altered by in increase in the rate of infant mortality for one generation?

Possible Answers:

Each population would be altered equally by an increase in infant mortality for one generation.

A population with demographics like those depicted in Model 3

A population with demographics like those depicted in Model 1

A population with demographics like those depicted in Model 2

Correct answer:

A population with demographics like those depicted in Model 2

Explanation:

A population with demographics like those depicted in Model 2 would be most drastically affected by an increase in the rate of infant mortality for one generation. Model 2 depicts a population that is already in a state of decline due to its relatively few young and reproducing members. An increase in the rate of infant mortality would affect this population more than those with demographics depicted in other models because the other models have comparatively more young members and would thus be able to more quickly recover from the decrease caused by the increase in infant mortality, whereas it would take an already-declining population longer to recover from such a decrease if it recovered at all.

Example Question #457 : Biology

A mycologist performed an experiment to determine the effect of methanol on the mold Neurospora crassa.

1,500 Neurospora spores were divided evenly into five groups of three large glass test tubes each. Then each test tube was filled with 5.0 mL of liquid nutrient solution and either 0 mL, 0.5 mL, 1.0 mL, 1.5 mL, or 2.0 mL of methanol. The tubes were placed in an incubator at 28oC overnight to germinate, and then their aerial growth was marked beginning the next morning and every twelve hours thereafter for two days.

Table 1 shows the average growth data with  hours representing the morning after germination and  hours representing the end of the two-day experiment.

Table_science

Suppose another experimenter repeated the mycologists experiment, but thinks he mislabeled one of his cultures. He sends the mycologists the following data for the potentially mislabeled tube.

Problem1

Based on the data from the mycologists study, which of the following can you conclude?

Possible Answers:

The experimenter labeled the tube incorrectly; the tube most likely has 0.0 mL methanol added.

The experimenter labeled the tube incorrectly; the tube most likely has 1.5 mL methanol added.

The experimenter labeled the tube correctly; the tube most likely has 1.0 mL methanol added.

The experimenter labeled the tube incorrectly; the tube most likely has 0.5 mL methanol added.

Correct answer:

The experimenter labeled the tube incorrectly; the tube most likely has 1.5 mL methanol added.

Explanation:

The data presented is most similar to the data from the mycologist for the cultures with 1.5 mL added. The data reported by the mycologist are averages, so the data collected by the experimenter for the mislableled tube may not be exactly the same due to scientific variability.

Example Question #458 : Biology

A mycologist performed an experiment to determine the effect of methanol on the mold Neurospora crassa.

1,500 Neurospora spores were divided evenly into five groups of three large glass test tubes each. Then each test tube was filled with 5.0 mL of liquid nutrient solution and either 0 mL, 0.5 mL, 1.0 mL, 1.5 mL, or 2.0 mL of methanol. The tubes were placed in an incubator at 28oC overnight to germinate, and then their aerial growth was marked beginning the next morning and every twelve hours thereafter for two days.

Table 1 shows the average growth data with  hours representing the morning after germination and  hours representing the end of the two-day experiment.

Table_science

Suppose the mycologist repeated the same experiment with an additional concentration of methanol, 0.25 mL, added. 

Based on the data in Table 1, which of the following is the best guess of the order of the concentrations of methanol added from most growth to least growth at 12 hours?

Possible Answers:

Correct answer:

Explanation:

Since we don't know what the data for 0.25 mL added look like, we can guess for now that it would fall between the data for 0.0 mL methanol added and 0.5 mL of methanol added. So, any ordering of these together would be a reasonable guess. We would expect, however, that the growth rates for 1.0 mL, 1.5 mL, and 2.0 mL methanol added would be consistent with the order in the experiment. Certainly, 2.0 mL would always be the least growth. 

Example Question #459 : Biology

A science class has been assigned a group project. Three different groups have been asked to plant a small pallet of grass and record growth over the course of 3 weeks. One blade of grass per trial was designated as the blade of grass to measure each week (the grass height for "Week 0" corresponds to the day the grass was planted). Every Monday (including the day it was planted) this same blade of grass is measured and its height (in inches) is recorded in a data table. The data collected by Group 1 corresponds to Table 1, Group 2 corresponds to Table 2, and Group 3 corresponds to Table 3.

Each group had two control conditions and one variable condition. The three conditions are:

  • the amount of water given to the grass
  • the type of soil the grass was planted in
  • the amount of sunlight the grass is exposed to every day

The variables and data collected are as follows:

Group 1 variable: different amounts of water 

Table 1

Trial A - one cup of water is poured on the grass every Monday after measuring

Trial B - two cups of water are poured on the grass every Monday after measuring

Trial C - three cups of water are poured on the grass every Monday after measuring

 

Group 2 variable: different types of soil

Table 2

Trial D - standard potting soil is used

Trial E - large rocks are mixed into the standard potting soil before the grass is planted

Trial F - small stones and pebbles are mixed into the standard potting soil before the grass is planted

 

Group 3 variable: different sunlight exposure

Table 3

Trial G - the grass is given 3 hours of sun exposure per day

Trial H - the grass is given 6 hours of sun exposure per day

Trial J - the grass is given 9 hours of sun exposure per day

Which of the following could explain why the grass in Trial E failed to change height between week 0 and week 3?

I. The grass was not watered enough and died

II. The small stones and pebbles in the soil kept the grass from getting nutrients from the soil

III. The large rocks in the soil kept the grass roots from growing long enough to get the nutrients from the soil

IV. The grass was not exposed to enough sunlight and died

Possible Answers:

II only

II and III

I and IV

III only

I and III

Correct answer:

III only

Explanation:

Options I and IV cannot be the answer, because the grass in Trial E had just as much sunlight exposure and water as the grass in Trials D and F, both of which grew successfully. This means a different variable was responsible for the stunted growth of the grass. Option II cannot be the answer because the small stones and pebbles were placed in the soil for Trial F. Therefore, the only correct answer is option III.

Example Question #460 : Biology

A science class has been assigned a group project. Three different groups have been asked to plant a small pallet of grass and record growth over the course of 3 weeks. One blade of grass per trial was designated as the blade of grass to measure each week (the grass height for "Week 0" corresponds to the day the grass was planted). Every Monday (including the day it was planted) this same blade of grass is measured and its height (in inches) is recorded in a data table. The data collected by Group 1 corresponds to Table 1, Group 2 corresponds to Table 2, and Group 3 corresponds to Table 3.

Each group had two control conditions and one variable condition. The three conditions are:

  • the amount of water given to the grass
  • the type of soil the grass was planted in
  • the amount of sunlight the grass is exposed to every day

The variables and data collected are as follows:

Group 1 variable: different amounts of water 

Table 1

Trial A - one cup of water is poured on the grass every Monday after measuring

Trial B - two cups of water are poured on the grass every Monday after measuring

Trial C - three cups of water are poured on the grass every Monday after measuring

 

Group 2 variable: different types of soil

Table 2

Trial D - standard potting soil is used

Trial E - large rocks are mixed into the standard potting soil before the grass is planted

Trial F - small stones and pebbles are mixed into the standard potting soil before the grass is planted

 

Group 3 variable: different sunlight exposure

Table 3

Trial G - the grass is given 3 hours of sun exposure per day

Trial H - the grass is given 6 hours of sun exposure per day

Trial J - the grass is given 9 hours of sun exposure per day

A local farmer wants to plant some new grass for his animals to graze. He wants a grass that will grow quickly during the summer so that his animals can graze all they want without worrying about running out of grass. The grass he plans to plant will grow in a standard soil (similar to the potting soil used in the class experiment) and is exposed to lots of sunlight. Would the grass being tested in this class be a good fit for this farmer's needs?

Possible Answers:

No; the data collected in Trial E implies that the grass being tested would not meet the farmer's needs

Yes; the data collected in Trial F implies that the grass being tested would meet the farmer's needs

Yes; the data collected in Trial G implies that the grass being tested would meet the farmer's needs

No; the data collected in Trial C implies that the grass being tested would not meet the farmer's needs

Yes; the data collected in Trial J implies that the grass being tested would meet the farmer's needs

Correct answer:

Yes; the data collected in Trial J implies that the grass being tested would meet the farmer's needs

Explanation:

The farmer's land has high exposure to sunlight and soil similar to the potting soil used in the experiment. The results of Trial J tell us that lots of sunlight (with other conditions constant) causes the grass to grow more quickly than if there is less sunlight (as in Trials G and H). The farmer wants his grass to grow quickly under these conditions, so Trial J does imply that the grass being tested would meet the farmer's needs.

Example Question #461 : Biology

A science class has been assigned a group project. Three different groups have been asked to plant a small pallet of grass and record growth over the course of 3 weeks. One blade of grass per trial was designated as the blade of grass to measure each week (the grass height for "Week 0" corresponds to the day the grass was planted). Every Monday (including the day it was planted) this same blade of grass is measured and its height (in inches) is recorded in a data table. The data collected by Group 1 corresponds to Table 1, Group 2 corresponds to Table 2, and Group 3 corresponds to Table 3.

Each group had two control conditions and one variable condition. The three conditions are:

  • the amount of water given to the grass
  • the type of soil the grass was planted in
  • the amount of sunlight the grass is exposed to every day

The variables and data collected are as follows:

Group 1 variable: different amounts of water 

Table 1

Trial A - one cup of water is poured on the grass every Monday after measuring

Trial B - two cups of water are poured on the grass every Monday after measuring

Trial C - three cups of water are poured on the grass every Monday after measuring

 

Group 2 variable: different types of soil

Table 2

Trial D - standard potting soil is used

Trial E - large rocks are mixed into the standard potting soil before the grass is planted

Trial F - small stones and pebbles are mixed into the standard potting soil before the grass is planted

 

Group 3 variable: different sunlight exposure

Table 3

Trial G - the grass is given 3 hours of sun exposure per day

Trial H - the grass is given 6 hours of sun exposure per day

Trial J - the grass is given 9 hours of sun exposure per day

What do the results from Trials A, B, and C imply about the nature of the grass being tested?

Possible Answers:

None of the other answers are correct

The grass being tested grows at the same rate no matter how much water is used

The grass being tested grows more quickly when it is hydrated by smaller amounts of water

The grass being tested grows more quickly when it is hydrated by larger amounts of water

The grass being tested grows more slowly when it is hydrated by smaller amounts of water

Correct answer:

The grass being tested grows more quickly when it is hydrated by smaller amounts of water

Explanation:

Trial A uses less water than Trial B, and both use less water than Trial C. Consequently, the grass grows tallest in Trial A, shortest in Trial C, and in the middle in Trial B. Therefore, the nature of the grass is to grow more quickly when it is hydrated by smaller amounts of water.

Learning Tools by Varsity Tutors