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WorksheetsPraxis Science
Total questions: 54
Worksheet time: 28mins
The process by which a gas becomes a liquid is called
Condensation
Freezing
melting
reduction
Which of the following human organs is responsible for the formation of sperm cells?
Pancreas
Thyroid
Ovary
Testis
Which of the following best describes the approximate length of time it takes Earth to rotate once about its axis?
One hour
One day
One month
One year
Which THREE of the following are generally acceptable rules for laboratory activities?
Students should wash their hands after mixing chemicals in the laboratory.
Students should inform the teacher immediately of any accidents or spills in the laboratory.
Students should use cracked glassware only when the teacher is in the laboratory.
Students should read instructions thoroughly before performing laboratory procedures.
Which of the following processes most directly involves the movement of water from the atmosphere to Earth’s surface?
Infiltration
Precipitation
Transpiration
Sublimation
Which of the following is an important function of the digestive system?
Absorbing nutrients into the body
Transporting signals to and from different parts of the body
Providing structural support for the body
Protecting the body from ultraviolet radiation
As a rock begins tumbling down a hillside, most of its gravitational potential energy is converted into
kinetic energy
thermal energy
chemical energy
nuclear energy
Which of the following is the best example of an interaction between different biotic factors in an ecosystem?
A caterpillar undergoing metamorphosis
A plant absorbing sunlight
A grazing animal eating plants
An icicle melting on a warm day
A neutral atom becomes a positive ion when it loses one or more
electrons
neutrons
protons
nuclei
Which of the following best describes a galaxy?
A small celestial body composed of ice
A giant planet orbited by ten or more moons
A collection of planets revolving around a star
A large cluster of stars, dust, and gas
An object is moving in a straight line at a constant speed. What will happen if a constant force is then applied to the object in the same direction in which the object is moving?
The object will stop moving.
The object will continue moving in the same direction but will slow down.
The object will continue moving in the same direction but will speed up.
The object will move in the opposite direction but at the same speed as before.
Which of the following molecules is a product of cellular respiration and is used for energy transfer in cells?
ATP
Carbon dioxide
Oxygen
Water
Researchers found fossils of marine organisms in rock layers that are located high above sea level. Which of the following conclusions is best supported by the researchers’ observations?
The fossils were transported to the research site by wind currents.
The rock layer in which the fossils were found is igneous rock.
The organisms from which the fossils were formed lived less than a hundred years ago.
The area containing the rock layers was previously covered by water.
During a total solar eclipse, the Moon is in which of the following phases?
New Moon
First-quarter Moon
Full Moon
Third-quarter Moon
Which of the following is a primary function of plant roots?
Transporting seeds away from a plant
Anchoring the plant body to the ground
Transferring pollen between flowers
Absorbing sunlight for photosynthesis
Which of the following best describes the type of chemical reaction that occurs when the acid H C lHCl is mixed with the base N a O HNaOH in a solution?
Combustion
Decomposition
Neutralization
Dehydration
Which of the following systems is responsible for the production of hormones?
Immune
Endocrine
Digestive
Skeletal
Which of the following is a method of heat transfer?
Nuclear decay
Insulation
Transpiration
Convection
Which of the following best describes where most earthquakes occur?
In the middle of continents
Where streams merge with rivers
In Earth’s inner core
At tectonic plate boundaries
The preceding balanced chemical equation represents a reaction between methane (C H 4)(CH4)(CH4) and oxygen (O 2)(O2)(O2) that produces carbon dioxide (C O 2)(CO2)(CO2) and water (H 2 O)(H2O)(H2O). Based on the balanced chemical equation, how many molecules of oxygen react with each molecule of methane?
1
2
3
4
Which of the following biomes has the greatest diversity of species?
Cold desert
Temperate grassland
Alpine tundra
Tropical rain forest
Which THREE of the following types of household waste are most likely to be accepted by a curbside recycling program?
Dry newspaper
Clean aluminum cans
Rinsed glass jars
Food-soiled waxed paper
Which of the following processes in a plant’s life cycle involves the emergence of leaves and roots from a seed?
Germination
Fertilization
Pollination
Flowering
On the periodic table, the elements lithium, sodium, and potassium are grouped together in the first column. Based on their locations on the periodic table, which of the following is most likely true about the elements lithium, sodium, and potassium?
They have the same atomic number.
They have the same atomic mass.
They have similar chemical properties.
They have similar melting points.
An animal is found to have the following characteristics: It has a backbone and soft, moist skin that is covered by a slippery layer of mucus. It goes through complete metamorphosis in its life cycle, and it lives part of its life in water and part of its life on land. To which of the following groups does the animal most likely belong?
Amphibians
Insects
Mammals
Reptiles
In an activity, students filled two identical containers with equal volumes of either freshwater or salt water. The students then placed different objects, one at a time, in the containers and observed whether the objects sank or floated. Which of the following statements best accounts for an observation that the same object sank in the freshwater but floated in the salt water?
The freshwater was colder than the salt water.
The freshwater weighed more than the salt water.
The salt water was denser than the freshwater.
The salt water was more transparent than the freshwater.
Which of the following elements are most abundant in the Sun?
Hydrogen and helium
Oxygen and carbon
Nitrogen and phosphorus
Uranium and plutonium
In plants, the chlorophyll used in photosynthesis is contained in which of the following cell structures?
The cell wall
The nucleus
The mitochondria
The chloroplasts
Which of the following is true about the formation of a covalent bond?
A covalent bond forms when electrons are shared between two atoms.
A covalent bond forms when one atom donates protons to another atom.
A covalent bond forms when two negatively charged atoms become attached to each other.
A covalent bond forms when the neutrons of one atom fuse with the neutrons of another atom.
Which of the following demonstrations provides the best opportunity for students to gain an understanding of why the Sun appears larger than other stars, even though many stars are actually larger than the Sun?
Positioning two lit bulbs of the same size on opposite sides of an observer but at the same distance from the observer
Positioning two lit bulbs of the same size at different distances from an observer
Positioning a large lit bulb and a small lit bulb at the same distance from an observer
Positioning a large lit bulb close to an observer and a small lit bulb far from the same observer
Bread molds belong to which of the following groups of organisms?
Bacteria
Animalia
Plantae
Fungi
Bread molds belong to which of the following groups of organisms?
Bacteria
Animalia
Plantae
Fungi
A teacher rubs an inflated balloon with a wool cloth and then holds the balloon over bits of paper that are lying on a table. The students in the class watch as the bits of paper rise from the table toward the balloon. Which of the following hypotheses is best supported by the observed interaction between the balloon and the bits of paper?
The balloon contains helium.
The balloon is unaffected by gravity.
The balloon has an electrostatic charge.
The balloon weighs more than the bits of paper do.
Two black mice have a litter that contains some black offspring and some brown offspring. In mice, black fur is dominant to brown fur. Which of the following best explains the presence of the brown offspring?
One parent was homozygous for black fur (uppercase B uppercase B)(BB), and one was heterozygous for black fur (uppercase B lowercase b)(Bb).
Both parents were heterozygous for black fur (uppercase B lowercase b)(Bb).
Both parents were homozygous for brown fur Both parents were homozygous for brown fur (lowercase b lowercase b)(bb).
Both parents were homozygous for black fur (uppercase B uppercase B)(BB).
Which of the following factors best accounts for the seasonal changes in weather conditions that occur at a particular location on Earth?
The Moon’s gravitational pull
Tilt of Earth’s rotational axis
Proximity to large bodies of water
Distortion of Earth’s magnetic field
In an investigation of the rusting process, students soaked a sample of steel wool in vinegar for approximately one minute. After removing the steel wool from the vinegar, the students squeezed it and blotted it with a paper towel. The students then wrapped the steel wool around the bulb of a thermometer and placed the steel wool and thermometer together in a covered beaker to allow the rusting process to occur. The students observed that the temperature reading of the thermometer gradually increased. Which of the following conclusions is best supported by the students’ observation?
A reaction occurred in which energy was created.
A reaction occurred in which energy was destroyed.
A reaction occurred in which energy was released.
No reaction occurred.
In which of the following ways can a tree-fall gap result in increased species diversity in a mature forest community?
By reducing the amount of carbon dioxide gas in the atmosphere
By increasing competition between birds for limited resources
By creating a barrier to the dispersal of seeds produced by mature trees
By providing a habitat in which shade-intolerant plants can grow
Which of the following statements best describes how the individual molecules in water vapor are different from those in liquid water?
They weigh less
They are farther apart.
They are composed of different elements.
They interact more strongly with one another.
Researchers are measuring surface salinity in different areas of an ocean. In which of the following areas will the researchers most likely find the highest surface salinity?
An area in which cooler temperatures are causing heavy rainfall
An area in which warmer temperatures are causing icebergs to melt
An area in which river flow is causing a mixing of freshwater with seawater
An area in which warm, dry winds are causing a high rate of evaporation
The scientific name for a domestic cat is Felis catus. Which of the following classification levels is indicated by the first part of the scientific name?
Order
Genus
Family
Kingdom
Which of the following most likely accounts for structural and functional differences between the skin cells, smooth muscle cells, and liver cells of the same person?
Differences in the genetic code
Differences in chromosome number
Differences in gene expression
Differences in mutation rates
In a demonstration of the Doppler effect, an observer who is standing still will most likely hear a sound’s pitch increase when the source of the sound does which of the following?
Remains motionless
Moves toward the observer
Moves away from the observer
Revolves in a circle around the observer
In which of the following types of power plants would the normal generation of electricity most likely produce the least amount of carbon dioxide gas?
Nuclear-fueled
Coal-fueled
Natural gas–fueled
Oil-fueled
Which of the following typically increases with increasing depth in the open ocean?
Biomass
Sunlight
Temperature
Pressure
Which of the following phenomena best accounts for an observation that an object underwater appears to be closer to the water’s surface than it really is?
The bouncing of light off a smooth, shiny surface
The warming of water by the absorption of energy from light
The casting of a shadow by an object through which light cannot pass
The bending of light as it passes from one substance to another
In an activity, students create models of landscapes by cutting two-liter plastic bottles in half lengthwise and filling them with different combinations of soil, sand, pebbles, and small plants. After positioning the models at an angle, the students pour equal amounts of water onto each model’s raised end and collect the runoff in beakers placed under each model’s lower end. The students then determine the dry mass of the sediment contained in the runoff from each model. Which of the following scientific questions can the students investigate most directly in the activity described?
How can growing plants break apart rocks?
Do earthworms improve soil fertility?
What are some factors that affect erosion?
Does temperature affect weathering rates?
Which of the following identifies the ultimate source of genetic variation in a population of organisms?
Nonfatal injuries to some members of the population
Predators that catch and eat some members of the population
Changes in the DNA of some members of the population
Seasonal weather changes in the area where the population is found
Which of the following scientists did pioneering research on the properties of radioactive elements?
Isaac Newton
Marie Curie
Nicolaus Copernicus
Charles Darwin
Which of the following conditions is required for the rapid replenishment of an aquifer?
Permeable soil
Steeply sloped land
Direct sunlight
High atmospheric pressure
Which THREE of the following statements about DNA are true?
DNA is a major source of cellular energy.
DNA stores and transmits genetic information.
DNA molecules have a double helix structure.
DNA is found in animal cells but not bacterial cells.
DNA is packaged into structures called chromosomes.
In which of the following layers of Earth’s atmosphere does most weather occur?
The troposphere, the layer closest to Earth’s surface
The stratosphere, the layer just above the troposphere
The mesosphere, the layer just above the stratosphere
The exosphere, the layer farthest from Earth’s surface
Which TWO of the following examples illustrate the application of genetic engineering in agriculture?
Scientists compared the cadmium concentrations of the grain produced by durum wheat grown in one of two different types of soil.
Scientists found that expression of a certain basil-plant gene in ripening tomatoes changes the flavor and aroma of the tomatoes.
Scientists investigated the amount of provitamin A that is produced and stored by certain naturally occurring strains of sweet potatoes.
Scientists developed a strain of corn with increased resistance to certain insects by inserting a bacterial gene into the corn’s genome.
As part of a unit on plate tectonics, students use various materials to construct physical models of Earth’s layered structure. The students will use the models to explore how the separate plates of the lithosphere, Earth’s solid outer layer, move over the asthenosphere, the partially molten upper portion of Earth’s mantle, over geologic time. Based on the description provided, which of the following materials would best represent the asthenosphere?
Paper that is thin, delicate, and easily punctured
A solid wood block that has a rough and uneven surface
Soft wax that can bend or stretch without breaking
A piece of stainless steel that is rigid and impermeable
Which of the following best describes a galaxy?
A small celestial body composed of ice
A giant planet orbited by ten or more moons
A collection of planets revolving around a star
A large cluster of stars, dust, and gas
