Scientists have long debated the origin of organic molecules on Earth.  Organic molecules are those based on the atom carbon, which can form four distinct bonds in contrast to the fewer number allowed in most other non-metals.  As a result of this property, carbon can give rise to the enormously complex molecular shapes necessary for life to arise.

Some scientists argue that organic matter was dissolved in water ice on comets, and brought to Earth early in its history. These comets crashed into the early Earth, and deposited carbon-based molecules in copious quantities to the Earth’s surface as their water melted.

In 2014, the first space probe landed on the comet 67P/Churyumov-Gerasimenko. Suppose that scientists find the following information from 5 distinct samples after landing on the comet. Each sample was taken at a single geographical location, but 5 meters deeper than the last.  Sample 1 was taken at a depth of 1 meter below the surface.

These samples were compared to 5 similar samples from the surface of Mars.  Scientists posited that this comparison would be meaningful because we know that life does not exist on Mars the same way that it does on Earth.  Thus, they are comparing a known non-biological celestial body, Mars, with another celestial body, the comet, which may be seeding life on suitable plants.

Before sending the probe into space, scientists suggested that organics may be found on celestial bodies like comets.  This suggestion, made in the absence of direct evidence, is most nearly:

Scientists have long debated the origin of organic molecules on Earth.  Organic molecules are those based on the atom carbon, which can form four distinct bonds in contrast to the fewer number allowed in most other non-metals.  As a result of this property, carbon can give rise to the enormously complex molecular shapes necessary for life to arise.

Some scientists argue that organic matter was dissolved in water ice on comets, and brought to Earth early in its history. These comets crashed into the early Earth, and deposited carbon-based molecules in copious quantities to the Earth’s surface as their water melted.

In 2014, the first space probe landed on the comet 67P/Churyumov-Gerasimenko. Suppose that scientists find the following information from 5 distinct samples after landing on the comet. Each sample was taken at a single geographical location, but 5 meters deeper than the last.  Sample 1 was taken at a depth of 1 meter below the surface.

These samples were compared to 5 similar samples from the surface of Mars.  Scientists posited that this comparison would be meaningful because we know that life does not exist on Mars the same way that it does on Earth.  Thus, they are comparing a known non-biological celestial body, Mars, with another celestial body, the comet, which may be seeding life on suitable plants.

After collecting the data, scientists involved in the study expressed their desire to repeat sampling on another comet.  Based only on the data in the passage, which of the following would suggest that organics would not be present?

I.  No water ice present in the comet

II.  The comet has no composition similarities to Earth

III.  The comet has no composition similarities to Mars

Scientists studying historical trends in climate change have a number of tools at their disposal. One method of analyzing paleoclimate data involves the use of fossilized pollen spores embedded in sediment. Pollen spores are specific to the plant that produced them. Because the spores are resilient and are widely-distributed by wind, they provide a snapshot of the vegetation that was widespread at a particular point in time. By identifying the age of a sample and the composition of the various spores, scientists can identify the prominent vegetation and use this information to gain insight into the climate at the time the spores were deposited.

Scientists took sediment samples from various depths of a lakebed. They found that five types of pollen spores make up the majority of spore deposits in each sample. In Table 1, plants are listed along with the respective temperature ranges and levels of precipitation for the areas in which they are commonly found. Table 2 shows the composition of the assortment of spores in each of the four samples taken by the scientists.

In order to replicate the above study, which of the following must be known?

Scientists studying historical trends in climate change have a number of tools at their disposal. One method of analyzing paleoclimate data involves the use of fossilized pollen spores embedded in sediment. Pollen spores are specific to the plant that produced them. Because the spores are resilient and are widely-distributed by wind, they provide a snapshot of the vegetation that was widespread at a particular point in time. By identifying the age of a sample and the composition of the various spores, scientists can identify the prominent vegetation and use this information to gain insight into the climate at the time the spores were deposited.

Scientists took sediment samples from various depths of a lakebed. They found that five types of pollen spores make up the majority of spore deposits in each sample. In Table 1, plants are listed along with the respective temperature ranges and levels of precipitation for the areas in which they are commonly found. Table 2 shows the composition of the assortment of spores in each of the four samples taken by the scientists.

In Table 2, what is the most likely explanation for the varying concentrations of spores from Plant 1 across each sample? 

Scientists studying historical trends in climate change have a number of tools at their disposal. One method of analyzing paleoclimate data involves the use of fossilized pollen spores embedded in sediment. Pollen spores are specific to the plant that produced them. Because the spores are resilient and are widely-distributed by wind, they provide a snapshot of the vegetation that was widespread at a particular point in time. By identifying the age of a sample and the composition of the various spores, scientists can identify the prominent vegetation and use this information to gain insight into the climate at the time the spores were deposited.

Scientists took sediment samples from various depths of a lakebed. They found that five types of pollen spores make up the majority of spore deposits in each sample. In Table 1, plants are listed along with the respective temperature ranges and levels of precipitation for the areas in which they are commonly found. Table 2 shows the composition of the assortment of spores in each of the four samples taken by the scientists.

In Table 1, what does the range "8 - 15" represent with respect to Plant E?

Study 1

A student wishes to study the effects of various household detergents on the mortality of a certain type of bacteria over an extended period of time. She introduces that type of bacteria to four separate agar plates (labeled Plate 1, Plate 2, Plate 3, and Plate 4), and then allows the bacteria to grow for three days. After this period, she treats Plate 1 with water, Plate 2 with Detergent X, Plate 3 with Detergent Y, and Plate 4 with Detergent Z. She then counts the number of bacterial colonies on each plate every eight hours for the next twenty-four hours.

Table 1

Study 2

The student now wishes to compare the effects of Detergent X and Detergent Y on the same type of bacteria as she used in Study 1. The student introduces that type of bacteria to three separate plates (labeled Plate I, Plate II, and Plate III), and then allows the bacteria to grow for 3 days. After this period, she treats Plate I with water, Plate II with Detergent X, and Plate III with Detergent Y. She then counts the number of bacterial colonies on each plate every eight hours for the next forty-eight hours.

How did the experimental designs of Study 1 and Study 2 differ?

A group of scientists wanted to investigate weather patterns in four cities across the United States. They conducted a series of experiments to look for similarities and differences among the four cities. The scientists measured wind speed and direction, amount of precipitation, and percentage of cloud cover for one week. Further explanation can be found below.

Experiment 1

Scientists measured wind speed using an anemometer at fifteen different locations around each city. Measurements were taken at each location three times a day and then averaged to get a daily wind speed for each city. This was repeated every day for one week, and the results were compiled into Table 1.

Experiment 2 

Scientists set up barometers at five locations in each city. At the end of each day, the precipitation levels in the five barometers were averaged to find the average daily precipitation, and the results are compiled in Table 2.

Experiment 3

For the final experiment, scientists placed upward-facing cameras atop the ten tallest buildings in each city. The cameras took one picture per hour. The scientists then used computer software to stitch together the images from all the cameras. The resulting meta-image was then analyzed with another computer program to find the percent of the sky covered by clouds. The results can be found in Table 3.

How many measurements did the scientists take per day in Experiment 1?

A group of scientists wanted to investigate weather patterns in four cities across the United States. They conducted a series of experiments to look for similarities and differences among the four cities. The scientists measured wind speed and direction, amount of precipitation, and percentage of cloud cover for one week. Further explanation can be found below.

Experiment 1

Scientists measured wind speed using an anemometer at fifteen different locations around each city. Measurements were taken at each location three times a day and then averaged to get a daily wind speed for each city. This was repeated every day for one week, and the results were compiled into Table 1.

Experiment 2 

Scientists set up barometers at five locations in each city. At the end of each day, the precipitation levels in the five barometers were averaged to find the average daily precipitation, and the results are compiled in Table 2.

Experiment 3

For the final experiment, scientists placed upward-facing cameras atop the ten tallest buildings in each city. The cameras took one picture per hour. The scientists then used computer software to stitch together the images from all the cameras. The resulting meta-image was then analyzed with another computer program to find the percent of the sky covered by clouds. The results can be found in Table 3.

Which two cities had the most similar weather patterns?

A group of scientists wanted to investigate weather patterns in four cities across the United States. They conducted a series of experiments to look for similarities and differences among the four cities. The scientists measured wind speed and direction, amount of precipitation, and percentage of cloud cover for one week. Further explanation can be found below.

Experiment 1

Scientists measured wind speed using an anemometer at 15 different locations around each city. Measurements were taken at each location 3 times a day and then averaged to get a daily wind speed for each city. This was repeated every day for one week and the results were compiled into table 1.

Experiment 2

Scientists set up barometers at five locations in each city. At the end of each day, the precipitation levels in the five barometers were averaged to find the average daily precipitation and the results are compiled in Table 2.

Experiment 3

For the final experiment, scientists placed upward facing cameras atop the ten tallest buildings in each city. The cameras took one picture per hour. The scientists then used computer software to stitch together the images from all the cameras. The resulting meta-image was then analyzed with another computer program to find the percent of the sky covered by clouds. The results can be found in table 3.

Suppose the scientists wanted to use this data to say that Tallahassee is always wetter than Kalamazoo. Which of the following would be a valid criticism of this line of thought?

A group of scientists wanted to investigate weather patterns in four cities across the United States. They conducted a series of experiments to look for similarities and differences among the four cities. The scientists measured wind speed and direction, amount of precipitation, and percentage of cloud cover for one week. Further explanation can be found below.

Experiment 1

Scientists measured wind speed using an anemometer at fifteen different locations around each city. Measurements were taken at each location three times a day and then averaged to get a daily wind speed for each city. This was repeated every day for one week, and the results were compiled into Table 1.

Experiment 2 

Scientists set up barometers at five locations in each city. At the end of each day, the precipitation levels in the five barometers were averaged to find the average daily precipitation, and the results are compiled in Table 2.

Experiment 3

For the final experiment, scientists placed upward-facing cameras atop the ten tallest buildings in each city. The cameras took one picture per hour. The scientists then used computer software to stitch together the images from all the cameras. The resulting meta-image was then analyzed with another computer program to find the percent of the sky covered by clouds. The results can be found in Table 3.

In which experiment was the greatest number of measurements taken?