Go to the main content of the page.
Logo, Maryland State Department of Education
MCAP, Maryland Comprehensive Assessment Program

This page shows a list of topics in the Life Science MISA public release collection at MSDE. Life Science MISA
Released Questions in Topic "Life Science and Earth and Space Science"

Select a question from the following list. The content of that question will be shown, and you can interact with it here.

Expand All Official Practice Test

This is test content.

Shark Tooth Fossils

Calvert Cliffs, located along the Chesapeake Bay in Maryland, contain sedimentary layers with fossils from the Miocene epoch that are 6 to 20 million years old. An epoch is a period of geologic time.

During the Miocene epoch, ancestors of Carcharodon carcharias (great white shark) inhabited the Chesapeake Bay, including Carcharodon hastalis, a shark that lived 20 to 3 million years ago, and Carcharodon megalodon, which lived 23 to 2.6 million years ago. As these organisms lived and died, their remains sank to the seafloor and were buried in sediment. A large amount of shark teeth fossils were found at Calvert Cliffs. Studies of teeth fossils show how sharks have evolved over time. Scientists compared teeth from great white sharks to teeth from the two shark ancestors, as shown.

These pictures show three shark teeth. The first picture is labeled C. carcharias. The picture shows a triangle-shaped tooth wider at the top and pointed at the lower end. A smooth band runs across the top wide end of the tooth. The two sides point downward and have jagged edges. The second picture is labeled C. hastalis. The picture shows a triangle-shaped tooth wider at the top and pointed at the lower end. A smooth band runs across the top wide end of the tooth. The two sides point downward and have jagged edges. The left side has a small curve halfway down the middle. The third picture is labeled C. megalodon. The picture shows a triangle-shaped tooth wider at the top and pointed at the lower end. A smooth band runs across the top wide end of the tooth but is V-shaped. The two sides point downward and have tiny, jagged edges.

Scientists also measured the shark teeth. They calculated the length-to-width ratios for the teeth from each species, as shown in the data table.

The table is titled Shark Tooth Sizes. The table has three columns and three rows. The first column heading is Species. The second column heading is Upper Jaw Teeth: Average Length-to-Width Ratio. The third column heading is Lower Jaw Teeth: Average Length-to-Width Ratio. The first row is C. carcharias, three point two four, two point one nine. The second row is C. hastalis, three point one one, two point four nine. The third row is C. megalodon, two point one eight, one point three eight.

This is test content.

Molecular Data

Scientists use molecular data such as DNA sequences from fossils to study the evolutionary history of sharks. DNA from the mitochondria is highly conserved among individuals in the same species. They analyzed a mitochondrial DNA sequence for the protein cytochrome B in several species of sharks, including the following:

  • Isurus paucus and Isurus oxyrinchus (mako shark)
  • Lamna nasus (porbeagle shark)
  • Carcharodon carcharias (great white shark)

The scientists compared the DNA sequences in the shark species and recorded the number of differences among them. A sequence difference of 1% corresponds to approximately 6 million years. The percent of gene sequence that is different between two species was used to estimate, in millions of years ago (mya), when individual species of shark diverged from a common ancestor. The phylogenetic tree shows the results of these comparisons.

The title of the phylogenetic tree is Shark Phylogenetic Tree. There is a short line on the left side of this image. Above the line is the label forty-six to sixty-five million years ago. To the right, the line has two branches. The bottom branch is a horizontal line with the label Lamna nasus. The top branch is a horizontal line with the label forty-three to sixty million years ago. At the end of this horizontal line, the line branches again into a bottom line and a top line. The bottom branch is a horizontal line to the right with the label Carcharodon carcharias. The top branch is a short, horizontal line to the right with the label thirty-four to forty-eight million years ago. At the end of this horizontal line, the line branches again into a bottom line and a top line. The bottom branch is a horizontal line to the right with the label Isurus paucus. The top branch is a horizontal line to the right with the label Isurus oxyrinchus.

This is test content.

The Miocene Epoch

During the Miocene epoch, temperatures on Earth increased. On land, forests disappeared while grasslands grew. Kelp forests formed in the oceans. The population of larger organisms increased on land and in the oceans.

Scientists study the climate of this period by analyzing sediments buried deep in the ocean bed, in ice caps, and in glaciers. The color, thickness, and chemical composition of these buried sediments provide scientists with clues about prehistoric climate.

The graph shows the changes in the climate on Earth from present to forty million years ago (mya).

The title of the graph is Climate Over Time. The x-axis is labeled Time in million years ago. The x-axis begins at zero and extends to the right to forty in intervals of ten. The y-axis shows an arrow pointing up and down. The top of the arrow is labeled Warmer and the bottom of the arrow is labeled Colder. The data line begins at an x-axis value of zero, and about halfway up on the y-axis. The line goes up and to the right until it reaches about three-fourths of the way up the y-axis and about sixteen on the x-axis, where it begins to fall. It continues to fall gradually to about two-thirds of the way up the y-axis at about twenty-three on the x-axis and then goes sharply up to just above three-fourths of the way up the y-axis at about twenty-five on the x-axis. It then drops sharply down to just below two-thirds of the way up the y-axis at twenty-six on the x-axis and stays at about that same level to about thirty-four on the x-axis. At thirty-five on the x-axis it rises sharply again back to about three-fourths of the way up the y-axis and then continues to rise until it ends at about four-fifths of the way up the y-axis and forty on the x-axis.

This is a question with 2 parts, including a multiple choice question that allows you to select only one option.

Changes during the Miocene epoch caused an increase in the number of shark fossils in the area of the Calvert Cliffs. Events that occurred during the Miocene epoch are listed, but they are not in the sequence that they occurred.

Event W: Dead organisms sink to the seafloor and get buried in sediments.
Event X: Sea levels rise and oceans expand.
Event Y: Marine animals inhabit the oceans covering Maryland.
Event Z: Climate warms.

Part A

Which of these were the first two in the sequence of events that led to the increase in shark fossils in the Calvert Cliffs?

  1. A.
    Event W, then Event Y
  2. B.
    Event Y, then Event W
  3. C.
    Event X, then Event Z
  4. D.
    Event Z, then Event X

Part B

Which of these were the last two in the sequence of events that led to the increase in shark fossils in the Calvert Cliffs?

  1. A.
    Event W, then Event Y
  2. B.
    Event Y, then Event W
  3. C.
    Event X, then Event Z
  4. D.
    Event Z, then Event Y

This is a multiple choice question that allows you to select only one option.

Changes in global climate during the Miocene epoch led to the formation of grasslands.

Which statement describes what most likely occurred as a result of these changes?

  1. A.
    The shape and structure of organisms changed as ecosystems changed.
  2. B.
    The predator population declined as the number of herbivores on the land increased.
  3. C.
    More fossils were buried in ice caps and in sediment beds as the animal population changed.
  4. D.
    More carbon dioxide was added to the atmosphere as the amount of vegetation on land increased.

This is a multiple choice question that allows you to select only one option.

Based on the Climate over Time graph, which of these changes most likely occurred between 21 million years ago and 14 million years ago?

  1. A.
    Melting ice caps led to increasing sea levels.
  2. B.
    Oceans cooled and polar ice sheets were formed.
  3. C.
    More sea-dwelling animals became land dwelling.
  4. D.
    Changing vegetation on land led to tectonic plate movements.

This is a multiple choice question that allows you to select only one option.

Based on the shark phylogenetic tree, the DNA of which two species is most closely related?

  1. A.
    L. nasus and I. oxyrinchus
  2. B.
    L. nasus and C. carcharias
  3. C.
    I. paucus and I. oxyrinchus
  4. D.
    I. paucus and C. carcharias

This is a test question that allows you to enter extended text in your response.

Identify and describe the evidence for common ancestry among different species of sharks.

Type your answer in the space provided.

This is test content.

Peatlands

Peatlands cover about 3% of Earth's land surface and store a tremendous amount of carbon. Peat is partially decomposed plant matter. An acidic, water-saturated environment is required for peat to form. Water limits the amount of oxygen available to interact with dead plant matter. The lack of oxygen prevents the plant matter from completely breaking down. Thus, the rate of accumulation of plant matter becomes greater than the rate of decomposition. Over millions of years, the decomposed plant matter stores carbon as it builds up to form peat. A picture of peat and a peatland is shown.

The picture shows peatland. The label on the top left reads Peatland and points to a large land area with grasses. There is an area of water in between the land areas. The label on the top right reads Peat and points to a dark, compacted, layered material rising up from the water.

In some countries, peat is burned as an alternative source of energy for cooking, heating, and generating electricity. In order to harvest peat for energy, or use the land for crops, peatlands must be drained. The removal of peat removes some of the stored carbon.

This is test content.

Wildfires

Carbon is also released from peatlands during wildfires. Cycles of wildfire and wildfire recovery have occurred in peatlands for thousands of years. Peatland wildfires burn plants above ground and some plant matter below ground. Sphagnum moss covers most peatlands but cannot survive if the peatland is drained. Recovery from wildfires helps balance the overall amount of carbon that is stored in peatlands.

Scientists measure how deep the fire penetrates into the layer of decomposing plant matter. This measurement is called the depth of burn. Scientists compared the effects of a wildfire on undrained and drained peatland in Canada. They recorded the depth of burn in both locations, as shown in the graph.

There is a graph titled Burned Peatland versus Drainage. The y-axis is labeled Average Depth of Burn in centimeters. It begins at zero and extends up to twenty in intervals of two. The bottom of the graph has two bars. The bar on the left is labeled Undrained Peatland and goes to seven. The bar on the right is labeled Drained Peatland and goes to nineteen.

Scientists used the depth of the burn to calculate and compare the amount of carbon lost in undrained and drained peatlands. The results are shown in the graph.

There is a graph titled Carbon Loss Due to a Wildfire. The y-axis is labeled Average Carbon Loss in kilograms per square meter. It begins at zero and extends up to twenty in intervals of two. The bottom of the graph has two bars. The bar on the left is labeled Undrained Peatland and goes to two. The bar on the right is labeled Drained Peatland and goes to seventeen.

This is test content.

Recovery after Wildfires

Scientists studied how drainage of peatlands affected trees growing 10 years after a wildfire. On the undrained site, scientists observed some willow and birch trees that were too young to identify by species. On the drained site, scientists recorded seven species of mature willow trees and two species of mature birch trees. Scientists also measured the percentage of ground that was shaded by trees.

There is a graph titled Tree Leaf Cover Ten Years after a Wildfire. The y-axis is labeled Ground That is Shaded by Trees in percent. It begins at zero and extends up to fifty in intervals of five. The bottom of the graph has two bars. The bar on the left is labeled Undrained Peatland and goes to fifteen. The bar on the right is labeled Drained Peatland and goes to forty six.

Scientists also inventoried the plants growing on the ground in both undrained and drained sites. The graphs show the differences between the sites.

There are two circle graphs. The title is Groundcover Ten Years after a Wildfire. The key reads white is bare surface. Light gray is sphagnum moss. Medium gray is other mosses. Black is other small plants.The graph on the left is labeled Undrained Peatland. The graph on the left shows white thirteen percent; light gray, twelve percent, medium gray seventy-five percent.The graph on the right is labeled Drained Peatland. The graph on the right shows medium gray, ten percent; black, one percent, white, eighty-nine percent.

This is a multiple choice question that allows you to select only one option.

Which statement best describes the role of sphagnum moss in maintaining peatland ecosystems?

  1. A.
    Sphagnum moss allows water to evaporate from the peatlands.
  2. B.
    Sphagnum moss helps peat decompose faster.
  3. C.
    Sphagnum moss decreases the amount of carbon stored in the peatland.
  4. D.
    Sphagnum moss helps minimize the damage to peatlands by wildfires.

This is a multiple choice question that allows you to select only one option.

Which of these helps increase the biodiversity of organisms in peatland ecosystems 10 years after a wildfire?

  1. A.
    The presence of water in the peatlands.
  2. B.
    Humans draining the peatlands for fuel.
  3. C.
    The depth of burned peat.
  4. D.
    Wildfires adding carbon to the atmosphere.

This is a test question that allows you to enter extended text in your response.

Use evidence to explain the effects of draining a peatland on the ecosystem. Predict how these changes could affect global ecosystems if global temperatures continue to rise. Give specific examples to justify your prediction.

Type your answer in the space provided.