ACT Science : Earth and Space Sciences
Study concepts, example questions & explanations for ACT Science
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Example Questions
Example Question #1065 : Act Science
Glaciers move, on average, 1 meter per day, although many are known to move faster or slower depending on their size. Whether they are alpine glaciers, which form high in the mountains, or continental glaciers that cover huge areas of land near the poles, glaciers are responsible for breaking up rock and moving sediment as they move across the land.
Below is a chart of average speed of movement of an alpine glacier per year, as well the amount of sediment displaced by the glacier.
|
Year |
Average Glacial Movement |
Sediment movement per year (tons) |
|
1995 |
1.1 m/day |
2.2 |
|
1996 |
1.3 m/day |
2.6 |
|
1997 |
1.5 m/day |
3.0 |
|
1998 |
1.3 m/day |
2.2 |
|
2000 |
1.1 m/day |
1.8 |
|
2005 |
1.0 m/day |
1.6 |
|
2010 |
0.9 m/day |
1.5 |
Two scientists have done research on an alpine lake that lies in the path of the glacier. Each took five samples of sediment from the lake.
Scientist 1 believes that the glacier is beginning to melt as it moves lower in elevation, releasing some of the sediment it has carried into mountain streams and springs, causing the makeup of sediments in the lake to change. He notes that the sediment from the lake bed contains brown chert, a rock that can only be found in elevations higher than that of the lake. Scientist 1 took his sample from the sediments that washed ashore on the beach of the lake.
Scientist 2 believes the glacier is not melting, but displacing rock beds so that the sediment loosens and breaks free of the bedrock and then is carried by wind and other erosive elements to the lake. He notes that the sediment from the lake bed contains only trace amounts of the brown chert, not enough to suggest the glacier is melting. Scientist 2 took his samples from sediment deposits at the bottom of the lake.
Below is a chart of the sediment collection samples and the percentage of brown chert found in each.
|
Sample # |
Scientist 1: % Brown Chert |
Scientist 2: % Brown Chert |
|
1 |
5.2 |
0.9 |
|
2 |
7.1 |
1.2 |
|
3 |
6.3 |
0.4 |
|
4 |
6.5 |
0.8 |
|
5 |
5.8 |
1.0 |
If Scientist 2 had taken another five samples, this time from the beach instead of the bottom of the lake, how might the percentages change?
They would not change.
They would decrease.
They would increase.
They would more closely resemble those percentages found by Scientist 1.
They would be much larger than those of Scientist 1.
They would more closely resemble those percentages found by Scientist 1.
One cannot say for sure if the percentage would increase or decrease—that depends on a number of other factors- but if Scientist 2 collects his data in the same manner as Scientist 1, one can reasonably conclude his findings will be similar.
Example Question #1061 : Act Science
Glaciers move, on average, 1 meter per day, although many are known to move faster or slower depending on their size. Whether they are alpine glaciers, which form high in the mountains, or continental glaciers that cover huge areas of land near the poles, glaciers are responsible for breaking up rock and moving sediment as they move across the land.
Below is a chart of average speed of movement of an alpine glacier per year, as well the amount of sediment displaced by the glacier.
|
Year |
Average Glacial Movement |
Sediment movement per year (tons) |
|
1995 |
1.1 m/day |
2.2 |
|
1996 |
1.3 m/day |
2.6 |
|
1997 |
1.5 m/day |
3.0 |
|
1998 |
1.3 m/day |
2.2 |
|
2000 |
1.1 m/day |
1.8 |
|
2005 |
1.0 m/day |
1.6 |
|
2010 |
0.9 m/day |
1.5 |
Two scientists have done research on an alpine lake that lies in the path of the glacier. Each took five samples of sediment from the lake.
Scientist 1 believes that the glacier is beginning to melt as it moves lower in elevation, releasing some of the sediment it has carried into mountain streams and springs, causing the makeup of sediments in the lake to change. He notes that the sediment from the lake bed contains brown chert, a rock that can only be found in elevations higher than that of the lake. Scientist 1 took his sample from the sediments that washed ashore on the beach of the lake.
Scientist 2 believes the glacier is not melting, but displacing rock beds so that the sediment loosens and breaks free of the bedrock and then is carried by wind and other erosive elements to the lake. He notes that the sediment from the lake bed contains only trace amounts of the brown chert, not enough to suggest the glacier is melting. Scientist 2 took his samples from sediment deposits at the bottom of the lake.
Below is a chart of the sediment collection samples and the percentage of brown chert found in each.
|
Sample # |
Scientist 1: % Brown Chert |
Scientist 2: % Brown Chert |
|
1 |
5.2 |
0.9 |
|
2 |
7.1 |
1.2 |
|
3 |
6.3 |
0.4 |
|
4 |
6.5 |
0.8 |
|
5 |
5.8 |
1.0 |
A third scientist hypothesizes that the increase in sediment containing brown chert found in the lake can be explained by the unusually warm weather over the last 2 decades. Which scientist is more likely to agree with this hypothesis?
Scientist 2: because warm weather would account for the high percentage of brown chert found on the beach
Scientist 1: because warm weather would explain the melting of the glacier
Neither scientist
Scientist 2: because warm weather would explain high winds and rainfall that could carry sediment
Scientist 1: because the warm weather would explain the small percentage of brown chert in the lake bed
Scientist 1: because warm weather would explain the melting of the glacier
If the weather is unusually warm, the glacier might experience unusual melting, which could carry the sediment into the lake.
Example Question #1065 : Act Science
Above is the deer population of Routt County National Forest between 1905 and 2005. The First White-tail deer were introduced to the forest for hunting in 1905. They are not native to the area, though they thrived in the environment.
White tailed deer eat the seeds of coniferous trees, berries, and an assortment of other plants. They tend to roam in small family herds and stick to areas where water is abundant and is unlikely to freeze completely in the winter.
In 1995, an environmental scientist watched a small herd of deer for ten days, recording their movements and taking note of herd size and stopping place. Below is a chart of his results.
|
Day |
Travel distance (mi) |
Herd size |
Stopping place |
|
1 |
21 |
13 |
Bear Creek |
|
2 |
15 |
13 |
Yampa Valley |
|
5 |
19 |
13 |
Bear Creek |
|
8 |
11 |
10 |
Gilpin Lake |
|
10 |
22 |
10 |
Yampa Valley |
What could have led to the deer thriving in an envrionment to which they are not native?
Clean and acessible drinking water.
All of the answers.
Access to a diet they are familiar with.
Protection from natural predators.
All of the answers.
For the deer to thrive they would need food they can eat, water they can drink and to be safe from predators. Only in such good conditions could they multiply so quickly. Safety is paramount for population growth. After acquiring safety, the deer would need an environment that gave them food and water with regularity and without too much effort.
Example Question #23 : How To Find Research Summary In Earth And Space Sciences
Above is the deer population of Routt County National Forest between 1905 and 2005. The First White-tail deer were introduced to the forest for hunting in 1905. They are not native to the area, though they thrived in the environment.
White tailed deer eat the seeds of coniferous trees, berries, and an assortment of other plants. They tend to roam in small family herds and stick to areas where water is abundant and is unlikely to freeze completely in the winter.
In 1995, an environmental scientist watched a small herd of deer for ten days, recording their movements and taking note of herd size and stopping place. Below is a chart of his results.
|
Day |
Travel distance (mi) |
Herd size |
Stopping place |
|
1 |
21 |
13 |
Bear Creek |
|
2 |
15 |
13 |
Yampa Valley |
|
5 |
19 |
13 |
Bear Creek |
|
8 |
11 |
10 |
Gilpin Lake |
|
10 |
22 |
10 |
Yampa Valley |
According to the data he found about the herd, what statement could the scientist make about deer in general?
White-tailed deer are often preyed on by wolves, and must travel far to avoid them.
White-tailed deer travel great distances but remain in familiar territory.
White-tailed deer like to explore, and travel far to see new places.
White-tailed deer do not stray far from the valleys that make up their home.
White-tailed deer travel great distances but remain in familiar territory.
The scientist has noted the deer travel very far each day but frequent the same places. The deer move sever miles in between all of their resting spots, but do not seem to stay from their particular territory to explore a new place. It stands to reason, then, that these deer travel far but do not explore beyond known territory. There is not enough evidence to infer the deer are often preyed upon by wolves.
Example Question #24 : How To Find Research Summary In Earth And Space Sciences
Above is the deer population of Routt County National Forest between 1905 and 2005. The First White-tail deer were introduced to the forest for hunting in 1905. They are not native to the area, though they thrived in the environment.
White tailed deer eat the seeds of coniferous trees, berries, and an assortment of other plants. They tend to roam in small family herds and stick to areas where water is abundant and is unlikely to freeze completely in the winter.
In 1995, an environmental scientist watched a small herd of deer for ten days, recording their movements and taking note of herd size and stopping place. Below is a chart of his results.
|
Day |
Travel distance (mi) |
Herd size |
Stopping place |
|
1 |
21 |
13 |
Bear Creek |
|
2 |
15 |
13 |
Yampa Valley |
|
5 |
19 |
13 |
Bear Creek |
|
8 |
11 |
10 |
Gilpin Lake |
|
10 |
22 |
10 |
Yampa Valley |
What could be concluded about the larger population of white-tailed deer in Routt National Forest, given the data collected on a single herd?
There are no white-tailed deer in the North.
White-tailed deer can be found almost everywhere in the forest.
White-tailed deer reproduce quickly.
Hunters prefer elk to white-tailed deer.
White-tailed deer can be found almost everywhere in the forest.
The population of deer in the forest is very large- several hundred thousand now populate the area. Also note that the movement of a single herd of deer is great; a few deer can travel more than twenty miles in a day, if they chose to. Given the travel distance of one herd and the size of the population, one could therefore conclude they have spread out throughout much of the forest. If the movement of one herd of about a dozen is so great, the movement of a population of several hundred thousand must be very great.
Example Question #131 : Earth And Space Sciences
The cause of the extinction of dinosaurs 65 million years ago is currently debated. Some attribute the extinction to volcanic activity while others attribute it to asteroid or comet impact. Two scientists offer conflicting viewpoints on the most probable cause of the mass extinction.
Scientist A
The extinction of dinosaurs was most likely caused by the impact of an asteroid or large comet. Unusually high levels of the rare metal iridium (found in extraterrestrial material) have been discovered in a layer of clay deposited at just the time of the extinction. In addition, this layer of clay contained quartz grains with a crystal structure that has been distorted by exceedingly high pressures (almost certainly caused by an impact). This colossal impact brought about a period of severe cooling that affected dinosaur eggs rather than adult dinosaurs. Small reptiles could survive by protecting their minute eggs in a variety of ways. However, there was no way for dinosaurs to protect their large eggs against a quickly-changing climate.
Scientist B
The extinction of dinosaurs was most likely caused by a volcanic outburst. In general, volcanic eruptions can have potent effects on climate. In 1815 the volcano Tambora in Indonesia erupted, spreading a pall of dust around the globe that resulted in killing frosts around Europe. The much larger eruption that formed the Deccan basalts about 65 million years ago would have caused a deeper and more prolonged cooling that directly affected adult dinosaurs. The rare metal iridium has been found both in active volcanoes and in a layer of clay deposited around the time of the dinosaur extinction. Therefore the dinosaurs were most likely affected by a massive volcanic eruption.
Which of the following best explains why Scientist B mentions iridium?
Iridium was directly responsible for the extinction of dinosaurs
High levels of iridium led to a prolonged cooling
Iridium has been discovered in volcanoes and in a relevant layer of clay
Iridium is found in asteroids and comets
Iridium has been discovered in volcanoes and in a relevant layer of clay
Scientist B mentions iridium because the metal is found both in volcanoes and in the layer of clay, which supports the theory that a volcanic eruption resulted in the mass extinction. Only Scientist A discusses asteroids and comets. There is no evidence in the passage that iridium caused climate change or that iridium was directly responsible for the extinction.
Example Question #1071 : Act Science
The cause of the extinction of dinosaurs 65 million years ago is currently debated. Some attribute the extinction to volcanic activity while others attribute it to asteroid or comet impact. Two scientists offer conflicting viewpoints on the most probable cause of the mass extinction.
Scientist A
The extinction of dinosaurs was most likely caused by the impact of an asteroid or large comet. Unusually high levels of the rare metal iridium (found in extraterrestrial material) have been discovered in a layer of clay deposited at just the time of the extinction. In addition, this layer of clay contained quartz grains with a crystal structure that has been distorted by exceedingly high pressures (almost certainly caused by an impact). This colossal impact brought about a period of severe cooling that affected dinosaur eggs rather than adult dinosaurs. Small reptiles could survive by protecting their minute eggs in a variety of ways. However, there was no way for dinosaurs to protect their large eggs against a quickly-changing climate.
Scientist B
The extinction of dinosaurs was most likely caused by a volcanic outburst. In general, volcanic eruptions can have potent effects on climate. In 1815 the volcano Tambora in Indonesia erupted, spreading a pall of dust around the globe that resulted in killing frosts around Europe. The much larger eruption that formed the Deccan basalts about 65 million years ago would have caused a deeper and more prolonged cooling that directly affected adult dinosaurs. The rare metal iridium has been found both in active volcanoes and in a layer of clay deposited around the time of the dinosaur extinction. Therefore the dinosaurs were most likely affected by a massive volcanic eruption.
With which of the following statements are both scientists most likely to agree?
Massive climate change primarily affected adult dinosaurs
Massive climate change played a key role in the extinction
Massive climate change primarily affected dinosaur eggs
An extraterrestrial object brought about climate change 65 million years ago
Massive climate change played a key role in the extinction
Scientist A believes that an extraterrestrial object was responsible for the massive climate change, whereas Scientist B attributes the change to a volcanic eruption. Both scientists agree, however, that climate change led to the mass extinction. Scientist A believes that climate change affected dinosaur eggs while Scientist B believes climate change affected adult dinosaurs.
Example Question #131 : Earth And Space Sciences
The cause of the extinction of dinosaurs 65 million years ago is currently debated. Some attribute the extinction to volcanic activity while others attribute it to asteroid or comet impact. Two scientists offer conflicting viewpoints on the most probable cause of the mass extinction.
Scientist A
The extinction of dinosaurs was most likely caused by the impact of an asteroid or large comet. Unusually high levels of the rare metal iridium (found in extraterrestrial material) have been discovered in a layer of clay deposited at just the time of the extinction. In addition, this layer of clay contained quartz grains with a crystal structure that has been distorted by exceedingly high pressures (almost certainly caused by an impact). This colossal impact brought about a period of severe cooling that affected dinosaur eggs rather than adult dinosaurs. Small reptiles could survive by protecting their minute eggs in a variety of ways. However, there was no way for dinosaurs to protect their large eggs against a quickly-changing climate.
Scientist B
The extinction of dinosaurs was most likely caused by a volcanic outburst. In general, volcanic eruptions can have potent effects on climate. In 1815 the volcano Tambora in Indonesia erupted, spreading a pall of dust around the globe that resulted in killing frosts around Europe. The much larger eruption that formed the Deccan basalts about 65 million years ago would have caused a deeper and more prolonged cooling that directly affected adult dinosaurs. The rare metal iridium has been found both in active volcanoes and in a layer of clay deposited around the time of the dinosaur extinction. Therefore the dinosaurs were most likely affected by a massive volcanic eruption.
According to Scientist A, which of the following animals was most likely able to survive the climate change 65 million years ago?
Owl
Salmon
Tyrannosaurus rex
Lizard
Lizard
Scientist A states that certain reptiles were able to survive due to the small size of their eggs. The only small reptile listed here is a lizard.
Example Question #1072 : Act Science
The cause of the extinction of dinosaurs 65 million years ago is currently debated. Some attribute the extinction to volcanic activity while others attribute it to asteroid or comet impact. Two scientists offer conflicting viewpoints on the most probable cause of the mass extinction.
Scientist A
The extinction of dinosaurs was most likely caused by the impact of an asteroid or large comet. Unusually high levels of the rare metal iridium (found in extraterrestrial material) have been discovered in a layer of clay deposited at just the time of the extinction. In addition, this layer of clay contained quartz grains with a crystal structure that has been distorted by exceedingly high pressures (almost certainly caused by an impact). This colossal impact brought about a period of severe cooling that affected dinosaur eggs rather than adult dinosaurs. Small reptiles could survive by protecting their minute eggs in a variety of ways. However, there was no way for dinosaurs to protect their large eggs against a quickly-changing climate.
Scientist B
The extinction of dinosaurs was most likely caused by a volcanic outburst. In general, volcanic eruptions can have potent effects on climate. In 1815 the volcano Tambora in Indonesia erupted, spreading a pall of dust around the globe that resulted in killing frosts around Europe. The much larger eruption that formed the Deccan basalts about 65 million years ago would have caused a deeper and more prolonged cooling that directly affected adult dinosaurs. The rare metal iridium has been found both in active volcanoes and in a layer of clay deposited around the time of the dinosaur extinction. Therefore the dinosaurs were most likely affected by a massive volcanic eruption.
Nowadays, various natural phenomena can produce clouds of dust that spread over large areas. Based on the information in the passage, Scientist B would most likely predict which of the following outcomes near these affected areas?
Cooling
No significant climate change
Volcanic eruption
Warming
Cooling
Scientist B states that an 1815 volcanic eruption in Indonesia resulted in a pall of dust, which then led to cold temperatures around Europe. One can infer that dust clouds today would produce a similar effect.
Example Question #131 : Earth And Space Sciences
Scientists have recorded data in Region A, Region B, Region C and Region D. The data collected include the average daily temperature, the annual rainfall for the past year and the number of fresh water reservoirs. The scientists want to perform an experiment on wild life migration patterns.
In which region should the scientist perform their wildlife migration experiment?
Region C
Region D
Region A
Region B
Region B
Wildlife on Earth needs a water supply. If the scientists want to notice migration patterns of wildlife, the scientists will want a region with abundant life. Region B has the largest number of fresh water reservoirs, which would lead to the conclusion that the largest amount of wildlife diversity in this region. Therefore the scientists should perform their experiment in Region B.
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