Maryland Integrated Science Assessment — Questions and Answers

Question 1: Which of the following correctly describes the function of the cell membrane?

It contains the cell's genetic material and controls its activities.
It controls the passage of substances into and out of the cell. (Correct answer)
It acts as a rigid, protective layer that gives the cell a fixed shape.
It is the site of protein synthesis and modification.

Correct answer: It controls the passage of substances into and out of the cell.

The cell membrane is a selectively permeable barrier that encloses the cell. Its primary function is to regulate which molecules, such as nutrients, ions, and waste products, can enter or leave the cytoplasm, thereby maintaining the cell's internal environment.

Question 2: Polar bears, majestic creatures of the Arctic, are facing a dire threat due to climate change. As temperatures rise, their sea ice habitat is melting away, forcing them to travel longer distances to hunt for food. Without action to combat climate change, these magnificent animals may face extinction. What is the main idea of the passage?

The history of space exploration
The impact of climate change on polar bears (Correct answer)
The benefits of exercise
The importance of recycling

Correct answer: The impact of climate change on polar bears

Explanation: The passage discusses how climate change affects polar bears' habitat and survival, emphasizing the dire threat they face due to melting sea ice.

Question 3: Which of the following scenarios best describes a direct interaction where the biosphere affects the hydrosphere?

Extensive growth of algae in a lake depletes oxygen levels in the water. (Correct answer)
A river carves a channel through soil and rock.
Wind blows across a lake, creating waves.
A glacier melts, adding fresh water to the ocean.

Correct answer: Extensive growth of algae in a lake depletes oxygen levels in the water.

Algae are living organisms, part of the biosphere. Their life processes (growth, death, and decomposition) directly alter the chemical composition (oxygen levels) of the lake water, which is part of the hydrosphere.

Question 4: A student in Maryland observes that the days are much longer and the weather is warmer in June than in December. Which statement best explains this seasonal variation?

Increased sunspot activity on the Sun's surface releases more heat in June.
The Earth's rotation on its axis speeds up during the summer months, increasing daylight hours.
Earth's orbit is an ellipse, and Earth is closer to the Sun in the summer.
The Northern Hemisphere is tilted toward the Sun in June, receiving more direct solar energy. (Correct answer)

Correct answer: The Northern Hemisphere is tilted toward the Sun in June, receiving more direct solar energy.

Earth has seasons because its axis is tilted at approximately 23.5 degrees. When the Northern Hemisphere is tilted toward the Sun, it receives sunlight at a more direct angle and for a longer duration each day, resulting in summer. When it is tilted away, it receives less direct sunlight, resulting in winter. Earth is actually closest to the Sun in its orbit during the Northern Hemisphere's winter.

Question 5: In a particular species of fish, a river is dammed, separating the population into two isolated groups. The upstream environment is rocky and has fast-moving water, while the downstream environment is muddy with slow-moving water. Over thousands of years, the two groups become so genetically different that they can no longer interbreed. This process is an example of:

Gene flow
Speciation (Correct answer)
Genetic drift
Artificial selection

Correct answer: Speciation

Speciation is the evolutionary process by which populations evolve to become distinct species. In this scenario, the geographic barrier (the dam) leads to reproductive isolation, and the different environmental pressures in the upstream and downstream habitats drive the two populations to diverge through natural selection until they are separate species.

Question 6: Besides carbon dioxide, methane (CH₄) is another powerful greenhouse gas. Which of the following human activities is a major source of atmospheric methane?

Livestock farming and the decomposition of waste in landfills. (Correct answer)
The process of splitting atoms in nuclear power plants.
The manufacturing of cement and concrete.
The use of nitrogen-based fertilizers on farmland.

Correct answer: Livestock farming and the decomposition of waste in landfills.

Major human-related sources of methane include agriculture and waste management. Methane is produced by the digestive processes of livestock (like cattle) and is also released when organic matter decomposes in oxygen-poor environments, such as landfills.

Question 7: A swimmer pushes backward on the water with their hands. In response, the water pushes the swimmer forward. This is a direct application of which principle?

The Law of Force and Acceleration (Newton's Second Law)
The Law of Universal Gravitation
The Law of Inertia (Newton's First Law)
The Law of Action-Reaction (Newton's Third Law) (Correct answer)

Correct answer: The Law of Action-Reaction (Newton's Third Law)

Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. The swimmer's push on the water is the 'action,' and the water pushing back on the swimmer with an equal and opposite force is the 'reaction,' which propels the swimmer forward.

Question 8: What is the perimeter of a rectangle with a length of 8 meters and a width of 5 meters?

18 meters
26 meters (Correct answer)
40 meters
13 meters

Correct answer: 26 meters

Explanation: The perimeter of a rectangle is calculated by adding all four sides. For this rectangle: Length = 8 meters Width = 5 meters Perimeter = 2*(Length + Width) = 2*(8 + 5) = 2*(13) = 26 meters

Question 9: Photosynthesis is the process plants use to make their own food. What is the fundamental energy conversion that occurs during photosynthesis?

Kinetic energy is converted into potential energy.
Radiant energy is converted into chemical energy. (Correct answer)
Chemical energy is converted into radiant energy.
Thermal energy is converted into kinetic energy.

Correct answer: Radiant energy is converted into chemical energy.

During photosynthesis, plants capture radiant energy (light energy) from the sun. They use this energy to convert carbon dioxide and water into glucose (a sugar), which stores the energy in its chemical bonds. This process is a direct conversion of radiant energy into stored chemical energy.

Question 10: An instant cold pack is activated by breaking an inner pouch, allowing two substances to mix. The pack quickly becomes very cold. This is an example of what type of process?

An exothermic reaction
A physical change
An endothermic reaction (Correct answer)
A combustion reaction

Correct answer: An endothermic reaction

An endothermic reaction is a process that absorbs heat from its surroundings. This absorption of heat causes the temperature of the surroundings (the pack itself) to decrease, making it feel cold.

Question 11: In a small village nestled among the hills, a young boy named David embarks on a perilous journey to save his family from a fierce dragon that terrorizes the land. With bravery and determination, he faces unimaginable challenges to restore peace to his home. What is the theme of the story?

Love
Friendship
Betrayal
Courage (Correct answer)

Correct answer: Courage

Explanation: The theme of courage is evident as the protagonist, David, bravely faces the challenges posed by the fierce dragon to save his family and restore peace to his village.

Question 12: According to the most widely accepted scientific theory, how did the planets in our solar system form?

They are the remaining fragments from an ancient collision between two massive stars.
They were ejected as large molten masses directly from the surface of the Sun.
They formed from the gradual accumulation of dust and gas in a rotating disk around the young Sun. (Correct answer)
They were captured by the Sun's gravity as they traveled through deep space.

Correct answer: They formed from the gradual accumulation of dust and gas in a rotating disk around the young Sun.

The nebular hypothesis is the most accepted model for the formation of the solar system. It states that a giant cloud of gas and dust (a nebula) collapsed under gravity, forming a spinning protoplanetary disk. The Sun formed at the center, and the planets were created through the process of accretion, where dust and gas particles stuck together and gradually grew larger.

Question 13: The pelvic bones of modern whales are small, non-functional structures that are remnants of the hind limbs of their land-dwelling ancestors. These non-functional structures are best described as:

Analogous structures
Homologous structures
Embryonic structures
Vestigial structures (Correct answer)

Correct answer: Vestigial structures

Vestigial structures are genetically determined features that have lost most or all of their ancestral function in a given species but were functional in an ancestor. The whale's pelvic bones are a classic example, providing evidence of their evolution from four-legged terrestrial mammals.

Question 14: Which of the following is a primary characteristic that distinguishes the inner planets (Mercury, Venus, Earth, Mars) from the outer planets (Jupiter, Saturn, Uranus, Neptune)?

The inner planets have many moons, while the outer planets have few or no moons.
The inner planets are much larger and less dense than the outer planets.
The inner planets are primarily composed of rock and metal, while the outer planets are primarily composed of gas and ice. (Correct answer)
The inner planets have extensive ring systems, while the outer planets do not.

Correct answer: The inner planets are primarily composed of rock and metal, while the outer planets are primarily composed of gas and ice.

The primary distinction between the two groups of planets is their composition. The inner, or terrestrial, planets have solid, rocky surfaces. The outer planets are known as gas giants (Jupiter, Saturn) or ice giants (Uranus, Neptune) and are composed mainly of lighter elements like hydrogen, helium, and ices without a solid surface.

Question 15: What is the mode of the following set of numbers: 5, 8, 5, 2, 7, 5, 4, 9?

4
2
7
5 (Correct answer)

Correct answer: 5

Explanation: The mode of a set of numbers is the number that appears most frequently. Given the set of numbers: 5, 8, 5, 2, 7, 5, 4, 9 The number 5 appears three times, which is more than any other number in the set.

Question 16: The solar system is a fascinating subject that has intrigued humans for centuries. From the fiery surface of the sun to the icy depths of Pluto, each planet offers a unique glimpse into the wonders of our universe. What is the author's purpose in writing this passage?

To inform (Correct answer)
To entertain
To describe
To persuade

Correct answer: To inform

Explanation: The passage provides factual information about the solar system and its planets, aiming to educate the reader about its fascinating aspects.

Question 17: A student observes a cell under a microscope and notes the presence of a cell wall, ribosomes, and a circular loop of DNA not enclosed in a nucleus. Which of the following is the most likely classification for this cell?

An animal cell
A plant cell
A prokaryotic cell (Correct answer)
A fungal cell

Correct answer: A prokaryotic cell

The defining characteristics described—a cell wall, ribosomes, and genetic material not contained within a nucleus—are all hallmarks of a prokaryotic cell, such as a bacterium. Plant and fungal cells are eukaryotic and have a nucleus, and animal cells lack a cell wall.

Question 18: In a closed system, 22 grams of reactant X are completely reacted with 8 grams of reactant Y. According to the Law of Conservation of Mass, what is the expected total mass of the products?

14 grams.
Less than 30 grams if a gas is produced.
More than 30 grams if the reaction is exothermic.
30 grams. (Correct answer)

Correct answer: 30 grams.

The Law of Conservation of Mass states that in a closed system, mass is neither created nor destroyed. Therefore, the total mass of the reactants must equal the total mass of the products. In this case, 22 g + 8 g = 30 g.

Question 19: Which statement best explains why electromagnetic waves can travel through the vacuum of space but sound waves cannot?

Sound waves have too low a frequency to travel through a vacuum
Electromagnetic waves travel faster than sound, allowing them to cross empty space
Electromagnetic waves are self-propagating disturbances in electric and magnetic fields and need no medium, whereas sound waves require matter to transmit compressions (Correct answer)
Sound waves lose energy quickly while electromagnetic waves do not

Correct answer: Electromagnetic waves are self-propagating disturbances in electric and magnetic fields and need no medium, whereas sound waves require matter to transmit compressions

Electromagnetic waves are oscillating electric and magnetic fields that sustain each other as they travel, requiring no material medium, while sound waves are pressure disturbances that need matter (particles) to propagate.

Question 20: A new drug is developed that specifically targets and disables the mitochondria within a cell. What essential cellular process would be most directly inhibited by this drug?

DNA replication
Cellular respiration (Correct answer)
Protein synthesis
Photosynthesis

Correct answer: Cellular respiration

Mitochondria are known as the 'powerhouses' of the cell because they are the primary site of cellular respiration. This process converts glucose and oxygen into ATP (adenosine triphosphate), the main energy currency for most cellular functions. Disabling mitochondria would halt this energy production.

Question 21: Himalayan rabbits have a gene that codes for fur color. The enzyme produced by this gene is only active at cooler temperatures. In a warm environment, the rabbit's fur is white. However, if an area of its body, like its ears or nose, is exposed to cold, the fur in that area grows black. This scenario is an example of:

Environmental factors influencing gene expression. (Correct answer)
A spontaneous mutation that changes fur color.
The Law of Segregation in action.
Codominance, where both alleles are fully expressed.

Correct answer: Environmental factors influencing gene expression.

The Himalayan rabbit's fur color is a classic example of how environmental factors can affect the expression of traits (phenotype). The rabbit has the gene for black fur, but its expression is regulated by temperature. This shows that the variation of traits depends on both genetic and environmental factors.

Question 22: For a total solar eclipse to be observed from a specific location on Earth, which of the following alignments of the Sun, Moon, and Earth must occur?

The Sun must be positioned directly between the Earth and the Moon.
The Moon must be positioned directly between the Sun and Earth. (Correct answer)
The Earth must be positioned directly between the Sun and the Moon.
The Sun, Earth, and Moon must form a right angle.

Correct answer: The Moon must be positioned directly between the Sun and Earth.

A solar eclipse occurs when the Moon passes between the Sun and Earth, casting a shadow on Earth's surface. For a total eclipse, the alignment must be precise, with the Moon completely blocking the Sun's disk from the viewer's perspective on Earth.

Question 23: Despite his fear, the knight displayed valor in the face of danger, charging bravely into battle against the fearsome dragon. Which word is an antonym for "bravery"?

Fearlessness
Valor
Courage
Cowardice (Correct answer)

Correct answer: Cowardice

Explanation: Cowardice means lacking courage or bravery, making it the antonym of bravery in this context.

Question 24: An observer on Earth sees a full moon. Approximately one week later, which lunar phase will the observer most likely see?

First Quarter Moon
New Moon
Third Quarter Moon (Correct answer)
Another Full Moon

Correct answer: Third Quarter Moon

The lunar cycle takes about 29.5 days to complete. The phases proceed in a specific order: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, and Waning Crescent. The Third Quarter (or Last Quarter) phase occurs approximately one week after the Full Moon, when the Moon has completed another quarter of its orbit and appears as a half-moon.

Question 25: If a rectangle has a length of 10 units and a width of 4 units, what is its area?

20 square units
40 square units (Correct answer)
24 square units
30 square units

Correct answer: 40 square units

Explanation: To find the area of a rectangle, multiply its length by its width. Given: Length = 10 units Width = 4 units Area = Length × Width = 10 units × 4 units = 40 square units

Question 26: What is the next number in the sequence: 2, 5, 8, 11, ...?

15
14 (Correct answer)
13
12

Correct answer: 14

Explanation: To find the next number in the sequence, we observe that each number is increasing by 3: 2, 5, 8, 11,... So, to find the next number, we add 3 to the last number in the sequence: 11 + 3 = 14

Question 27: In a forest ecosystem, a deer eats plants, a wolf eats the deer, and fungi break down the wolf's remains after it dies. Which of the following correctly describes the flow of energy in this ecosystem?

Energy flows from the sun to the plants, then to the deer, and then to the wolf. The fungi do not use energy.
Energy flows from the plants to the sun, is absorbed by the deer and wolf, and is destroyed by the fungi.
Energy flows from the sun to the plants, then to the deer, and then to the wolf. Energy is transferred to the fungi from the wolf's remains. (Correct answer)
Energy flows from the plants to the deer, then to the wolf, and is finally recycled by the fungi back to the plants.

Correct answer: Energy flows from the sun to the plants, then to the deer, and then to the wolf. Energy is transferred to the fungi from the wolf's remains.

Energy in most ecosystems originates from the sun and is captured by producers (plants) through photosynthesis. This energy is then transferred to primary consumers (deer) and then to secondary consumers (wolf). When the wolf dies, decomposers (fungi) obtain energy by breaking down its organic matter. Unlike matter, energy is not recycled; it flows through the ecosystem and is lost as heat at each transfer.

Question 28: The process of chemical weathering, where slightly acidic rainwater dissolves limestone to form caves, is a primary example of an interaction between which two spheres?

Hydrosphere and Geosphere (Correct answer)
Atmosphere and Biosphere
Biosphere and Hydrosphere
Geosphere and Atmosphere

Correct answer: Hydrosphere and Geosphere

Rainwater (hydrosphere) acts as a chemical agent that breaks down and erodes the limestone rock (geosphere) over long periods, creating geological features like caves.

Question 29: A student uses a battery-powered flashlight to see in a dark room. Which of the following describes the primary energy conversions that take place?

Chemical energy to electrical energy to light and thermal energy (Correct answer)
Electrical energy to thermal energy to light energy
Kinetic energy to electrical energy to light energy
Radiant energy to chemical energy to electrical energy

Correct answer: Chemical energy to electrical energy to light and thermal energy

The batteries in a flashlight store chemical potential energy. When the flashlight is turned on, this chemical energy is converted into electrical energy, which flows through the circuit. The bulb then converts the electrical energy into radiant (light) energy and thermal (heat) energy.

Question 30: Which human activity is the largest source of the excess carbon dioxide (CO₂) that is enhancing the greenhouse effect and causing recent climate change?

The burning of fossil fuels for electricity, heat, and transportation. (Correct answer)
The disposal of organic waste in municipal landfills.
The use of chemical fertilizers in large-scale agriculture.
Large-scale deforestation, particularly in tropical regions.

Correct answer: The burning of fossil fuels for electricity, heat, and transportation.

The combustion of fossil fuels (coal, oil, and natural gas) for energy is the single largest human-caused source of carbon dioxide emissions. This process releases vast amounts of carbon that were stored underground for millions of years, significantly increasing the concentration of CO₂ in the atmosphere.

Question 31: If x = 7, what is the value of 2x − 3?

8
9
11 (Correct answer)
10

Correct answer: 11

Explanation: If x = 7, we can substitute this value into the expression 2x − 3 and calculate the result: 2x − 3 = 2 (7) − 3 = 14−3 = 11

Question 32: The large-scale removal of forests (deforestation) can lead to increased soil erosion. Without tree roots to hold the soil in place, wind and rain can wash it away more easily. This chain of events demonstrates how a change in the can directly impact the .

hydrosphere; atmosphere
geosphere; biosphere
atmosphere; hydrosphere
biosphere; geosphere (Correct answer)

Correct answer: biosphere; geosphere

The removal of trees and other plants, which are part of the biosphere, directly leads to the loss of soil, which is part of the geosphere. The living components are failing to protect the non-living, solid Earth component.

Question 33: What is the relationship between the frequency and wavelength of an electromagnetic wave?

They are directly proportional — higher frequency means longer wavelength
They are independent of each other
They are equal when measured in the same units
They are inversely proportional — higher frequency means shorter wavelength (Correct answer)

Correct answer: They are inversely proportional — higher frequency means shorter wavelength

Frequency and wavelength are inversely proportional; as frequency increases, wavelength decreases, since wave speed equals frequency times wavelength.

Question 34: A student pushes a heavy box across a rough floor but the box does not move. Which statement best explains this situation?

The applied force is converted entirely into heat.
The box has too much inertia to be moved.
The force of the student's push is less than the force of gravity on the box.
The force of static friction is equal to and opposite the student's pushing force. (Correct answer)

Correct answer: The force of static friction is equal to and opposite the student's pushing force.

For the box to remain stationary, the net force must be zero. The student's push is an applied force. This force is being counteracted by an equal and opposite force of static friction from the floor. Until the student's push exceeds the maximum static friction, the box will not move.

Question 35: In a hydroelectric power plant, a dam holds back a large volume of water in a reservoir. When the water is released, it flows through a turbine, which spins a generator to produce electricity. What is the correct sequence of energy transformations in this process?

Chemical energy → Kinetic energy → Electrical energy
Kinetic energy → Electrical energy → Potential energy
Thermal energy → Mechanical energy → Electrical energy
Potential energy → Kinetic energy → Electrical energy (Correct answer)

Correct answer: Potential energy → Kinetic energy → Electrical energy

The water held in the reservoir at a high elevation possesses gravitational potential energy. When released, this potential energy is converted into kinetic energy as the water flows downwards. The moving water spins a turbine (mechanical energy), which powers a generator that converts this motion into electrical energy.

Question 36: Which of the following scenarios describes an object experiencing a net unbalanced force?

A satellite orbiting Earth at a constant speed. (Correct answer)
A helium balloon floating stationary in the middle of a room.
A book resting motionless on a tabletop.
A car driving in a straight line at a constant 60 mph.

Correct answer: A satellite orbiting Earth at a constant speed.

A net unbalanced force causes acceleration, which is a change in velocity (speed or direction). A satellite orbiting Earth is constantly changing its direction, so it is continuously accelerating due to the unbalanced force of gravity, which acts as a centripetal force.

Question 37: A student wants to increase the rate of reaction between a solid lump of calcium carbonate and a hydrochloric acid solution. Which of the following actions would be LEAST effective at increasing the reaction rate?

Decreasing the concentration of the hydrochloric acid solution. (Correct answer)
Gently warming the hydrochloric acid solution.
Crushing the lump of calcium carbonate into a powder.
Stirring the mixture continuously.

Correct answer: Decreasing the concentration of the hydrochloric acid solution.

Decreasing the concentration of a reactant reduces the number of reactant particles in a given volume, which leads to fewer collisions per unit of time and therefore slows down the reaction rate. Increasing surface area (crushing), increasing temperature, and agitating the mixture all increase the reaction rate.

Question 38: A student is riding a skateboard at a constant velocity. Suddenly, the skateboard hits a crack in the sidewalk and stops, but the student continues to move forward. Which of the following principles best explains why the student continues to move forward?

Friction
Newton's Third Law (Action-Reaction)
Inertia (Newton's First Law) (Correct answer)
Gravitational Force

Correct answer: Inertia (Newton's First Law)

This is an example of Newton's First Law of Motion, also known as the law of inertia. The student's body was in motion and tends to remain in motion with the same velocity, even after the skateboard was stopped by an external force.

Question 39: Ultraviolet (UV) radiation from the Sun can cause sunburn because it:

Reflects off the atmosphere and is concentrated on Earth's surface
Has a longer wavelength than visible light and carries more heat energy
Has higher frequency than visible light and carries enough energy to damage skin cells (Correct answer)
Travels faster than visible light and delivers energy more quickly

Correct answer: Has higher frequency than visible light and carries enough energy to damage skin cells

UV radiation has higher frequency and more energy per photon than visible light, giving it enough energy to break chemical bonds and damage DNA in skin cells.

Question 40: What happens to the speed of light when it passes from air into water?

It decreases because water is denser (Correct answer)
It increases because water has a lower refractive index than air
It remains the same in all transparent media
It increases because water is denser

Correct answer: It decreases because water is denser

Light slows down when entering a denser medium like water because the index of refraction of water is greater than that of air.

Question 41: Scientists analyze air bubbles trapped deep within Antarctic ice cores. They find that over the past 800,000 years, atmospheric CO₂ levels and global temperatures have consistently risen and fallen together. What is the most logical conclusion that can be drawn from this strong correlation?

Volcanic activity has ceased to be a factor in climate during this period.
The amount of ice on Earth's surface directly controls the amount of CO₂ in the atmosphere.
Atmospheric carbon dioxide concentration is a critical factor in regulating Earth's temperature. (Correct answer)
Changes in Earth's orbit are the only factor that influences long-term climate.

Correct answer: Atmospheric carbon dioxide concentration is a critical factor in regulating Earth's temperature.

The consistent, repeating pattern found in ice core data shows a strong coupling between atmospheric CO₂ and global temperature. While orbital cycles can initiate warming or cooling, the resulting change in CO₂ acts as a powerful feedback that amplifies the temperature change, demonstrating that CO₂ is a principal control knob for Earth's climate.

Question 42: A student mixes two clear, colorless liquids in a beaker. They observe the formation of a white solid and notice the beaker feels warm to the touch. Which statement best explains these observations?

The liquids were contaminated, resulting in a precipitate.
A physical change occurred, causing one liquid to freeze.
The beaker absorbed heat from the room, causing a solid to form.
A chemical reaction occurred, indicated by the formation of a precipitate and a change in temperature. (Correct answer)

Correct answer: A chemical reaction occurred, indicated by the formation of a precipitate and a change in temperature.

The formation of a new substance with different properties (a solid precipitate from two liquids) and the release of energy as heat (an exothermic reaction) are two classic indicators that a chemical reaction has taken place.

Question 43: A large area of rainforest is cleared and burned to make way for agriculture. Which of the following describes the most significant, direct impact of this action on the global climate?

A temporary cooling effect from the smoke and ash blocking sunlight.
A decrease in the Earth's capacity to absorb carbon dioxide from the atmosphere. (Correct answer)
An increase in atmospheric oxygen levels from the burning of plant matter.
A major disruption in local wind patterns, leading to fewer hurricanes.

Correct answer: A decrease in the Earth's capacity to absorb carbon dioxide from the atmosphere.

Forests, especially large rainforests, act as critical 'carbon sinks,' absorbing massive amounts of CO₂ from the atmosphere for photosynthesis. Deforestation not only releases the carbon stored in the trees back into the atmosphere but also permanently removes that area's ability to absorb CO₂, leading to a net increase in greenhouse gases.

Question 44: Solve for x in the equation 3 (x − 2) = 15.

8
5
6
7 (Correct answer)

Correct answer: 7

Explanation: To solve the equation 3 (x − 2) = 15, follow these steps: Distribute the 3 to both terms inside the parentheses: 3 × X − 3 × 2 = 15 3x − 6 = 15 Add 6 to both sides of the equation: 3x − 6 + 6 = 15 + 6 3x = 21 Divide both sides by 3 to isolate x: 3𝑥/3 = 21/3 x = 7

Question 45: The chemical reaction 2 H₂O₂ → 2 H₂O + O₂ shows hydrogen peroxide changing into water and oxygen gas. How is this type of reaction best classified?

Decomposition (Correct answer)
Synthesis
Double-replacement
Single-replacement

Correct answer: Decomposition

A decomposition reaction occurs when a single, more complex compound breaks down into two or more simpler substances. In this case, hydrogen peroxide (H₂O₂) breaks down into water (H₂O) and oxygen (O₂).

Question 46: The world's oceans absorb a significant amount of the carbon dioxide released into the atmosphere by human activities. Which of the following is a direct chemical consequence of this absorption?

A decrease in the average salinity of the ocean's surface waters.
Increased ocean acidity, which harms marine organisms with shells. (Correct answer)
A rapid increase in dissolved oxygen levels, benefiting most fish.
A significant increase in the ocean's average temperature.

Correct answer: Increased ocean acidity, which harms marine organisms with shells.

When excess carbon dioxide (CO₂) dissolves in seawater, it forms carbonic acid (H₂CO₃), which lowers the ocean's pH. This process, known as ocean acidification, reduces the availability of carbonate ions that marine organisms like corals, clams, and oysters need to build their shells and skeletons.

Question 47: In an aquatic ecosystem, a sudden increase in agricultural runoff leads to eutrophication and a subsequent 'dead zone' where dissolved oxygen levels are extremely low. This condition is known as hypoxia. Which process is most directly inhibited in organisms living in this dead zone?

Anaerobic respiration
Chemosynthesis
Aerobic cellular respiration (Correct answer)
Photosynthesis

Correct answer: Aerobic cellular respiration

Aerobic cellular respiration is the process that uses oxygen to break down food molecules and release energy. In a hypoxic (low oxygen) environment, organisms that rely on this process cannot survive. Anaerobic respiration does not require oxygen. While the causes of the dead zone relate to photosynthesis (algal blooms), the direct process inhibited in animals by the lack of oxygen is aerobic respiration.

Question 48: A student drops a rubber ball from a height of one meter. The ball bounces back up, but not to its original height. According to the Law of Conservation of Energy, what best explains why the ball does not reach its starting height?

The force of gravity on the ball decreased after the bounce.
The ball did not have enough kinetic energy to begin with.
Some mechanical energy was converted into thermal and sound energy. (Correct answer)
Some of the ball's energy was destroyed during the bounce.

Correct answer: Some mechanical energy was converted into thermal and sound energy.

The Law of Conservation of Energy states that energy cannot be created or destroyed, only transformed. When the ball hits the floor, some of its kinetic energy is converted into other forms, primarily thermal energy (heat) due to friction and the deformation of the ball, and sound energy. This loss of mechanical energy prevents it from returning to its original height.

Question 49: What is a key difference between the outcomes of mitosis and meiosis?

Mitosis is used for sexual reproduction, while meiosis is used for growth and repair.
Mitosis doubles the chromosome number in each daughter cell, while meiosis halves it.
Mitosis results in diploid cells that are genetically identical to the parent cell, while meiosis results in haploid cells that are genetically unique. (Correct answer)
Mitosis produces four genetically unique daughter cells, while meiosis produces two identical daughter cells.

Correct answer: Mitosis results in diploid cells that are genetically identical to the parent cell, while meiosis results in haploid cells that are genetically unique.

Mitosis is a process of cell division that results in two diploid daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth. Meiosis is a process where a single cell divides twice to produce four haploid cells containing half the original amount of genetic information. These cells are our sex cells – sperm in males, eggs in females, and they are genetically unique due to recombination.

Question 50: A student pushes a heavy box across a rough floor. After the student stops pushing, the box slides for a short distance and then stops. The student observes that the bottom of the box and the floor feel slightly warmer. This is because the box's kinetic energy was converted primarily into:

potential energy.
thermal energy. (Correct answer)
radiant energy.
chemical energy.

Correct answer: thermal energy.

Friction is a force that opposes motion. As the box slides across the rough floor, friction does work on the box, converting its kinetic energy (energy of motion) into thermal energy (heat). This is why both the box and the floor feel warmer after the interaction.

Question 51: A student is examining a diagram of genetic material. Which of the following statements correctly describes the relationship between DNA, genes, and chromosomes?

DNA is made of chromosomes, and genes are the proteins created by the chromosomes.
Chromosomes, DNA, and genes are all separate structures with no direct physical relationship.
Genes are made of chromosomes, which are then coiled into the larger structure of DNA.
Chromosomes are made of DNA, and genes are specific segments of that DNA that code for traits. (Correct answer)

Correct answer: Chromosomes are made of DNA, and genes are specific segments of that DNA that code for traits.

The correct answer accurately represents the hierarchical structure of genetic material. Chromosomes, located in the nucleus of eukaryotic cells, are tightly coiled structures composed of DNA and proteins. A gene is a specific sequence or segment of this DNA that holds the instructions for building a specific protein or functional RNA molecule, which in turn determines a particular trait.

Question 52: Sound waves traveling through air are best classified as which type of wave?

Transverse waves
Surface waves
Electromagnetic waves
Longitudinal waves (Correct answer)

Correct answer: Longitudinal waves

Sound waves are longitudinal (compressional) waves in which particle displacement is parallel to the direction the wave travels.

Question 53: What is the value of 15 − 3× (4 + 2)?

21
5
9
3 (Correct answer)

Correct answer: 3

Explanation: To solve the expression 15 − 3 × (4 + 2), follow the order of operations (PEMDAS/BODMAS): Perform the operation inside the parentheses: 4 + 2 = 6 Multiply: 3 × 6 = 18 Subtract: 15 − 18 = −3

Question 54: Imagine a hypothetical scenario where a new planet, with twice the mass of Earth, is discovered orbiting the Sun at the same distance as Earth. How would the Sun's gravitational force on this new planet compare to its force on Earth?

The gravitational force would be twice as strong. (Correct answer)
The gravitational force would remain the same.
The gravitational force would be half as strong.
The gravitational force would be four times as strong.

Correct answer: The gravitational force would be twice as strong.

According to Newton's Law of Universal Gravitation, the gravitational force between two objects is directly proportional to the product of their masses. If the distance remains constant and the mass of one object (the planet) is doubled, the gravitational force between it and the Sun will also double.

Question 55: If a car travels at a speed of 60 miles per hour, how far will it travel in 2.5 hours?

175 miles
200 miles
150 miles (Correct answer)
120 miles

Correct answer: 150 miles

Explanation: To find the distance traveled, we multiply the speed (rate) by the time traveled. Given: Speed = 60 miles per hour Time = 2.5 hours Distance = Speed × Time Distance = 60 miles/hour × 2.5 hours Distance = 150 miles

Maryland Integrated Science Assessment

The MISA (Maryland Integrated Science Assessment) is a state science exam administered to Maryland students in grades 5, 8, and high school, assessing mastery of Next Generation Science Standards across life science, physical science, Earth and space science, and engineering through real-world scenario-based item sets.

Questions

200 min

Time Limit

50%

To Pass

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Exam Rules

You can skip questions and return to them later
Flag questions for review before submitting
No feedback shown until you submit the entire exam
Unanswered questions count as wrong — answer everything
10 pretest questions are mixed in and don't affect your score
Timer auto-submits when time runs out
Your progress is auto-saved every 30 seconds

These practice questions were written with AI tools. They are not real exam questions. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy

Sources & references

Exam facts on this page (fees, format, dates, passing scores) are checked against these official sources; the date is our last check. Editorial policy

news.maryland.gov — Eligibility · verified Oct 2026