TExES™ Core Subjects EC-6 Practice Test 1 &2: Science (904)

Question Number 1

A teacher is preparing a unit on genetics. Part of this unit includes:

1. An introduction to the concept of genes as a determinant of physical traits

2. A discussion of dominant and recessive genes

3. An activity on the difference between genotypes and phenotypes

Which of the following lessons would be most appropriate to teach at the beginning of this lesson series?

An activity in which the students identify different physical traits in a group of flowers. [This option introduces the concept of genetics through physical differences in plants, which will build upon the students’ prior knowledge of plant biology from earlier in the year.]

A teacher is planning an activity about identifying sources and types of experimental error, where the students will be analyzing different types of data sets. Which of the following activities would provide the students with a meaningful opportunity to identify potential sources of experimental error?

Graphing a set of data containing a random error to look for outliers. [Graphing a set of data containing a random error can allow the student to see the outlier visually, as it does not align with the other data points.]

A class is preparing to start a unit on ecosystems. Which of the following topics of discussion would best promote student understanding of the change that occurs within a system?

Effects on an ecosystem caused by a population increase or decrease. [This discussion would lead to understanding that change occurs within systems such as ecosystems. An ecosystem can become unbalanced by population changes.]

Which of the following questions or problems would best be solved using scientific methods and principles?

Mrs. Smith is trying to determine which fertilizer will cause her ferns to grow the most. [Mrs. Smith can conduct an experiment and collect data to determine the answer.]

Which of the following options correctly pairs the body system with its role in regulating blood pH?

The urinary system clears acidic and basic molecules. [The kidneys in the urinary system remove acidic and basic molecules to maintain pH.]

A mouse population is comprised of mice with either brown or black fur. There are two alleles for fur color in the population: the dominant allele, B (black), and the recessive allele, b (brown). One brown mouse and one black mouse (with genotype Bb) are crossed and produce 8 offspring. What is the expected number of brown and black offspring?

4 black offspring, 4 brown offspring. The cross between Bb and bb results in 50% of the offspring with Bb genotypes (black phenotype) and 50% of the offspring with bb genotypes (brown phenotype).

	B	b
B	Bb	bb
B	Bb	bb

A teacher is finishing an introductory lesson on the states of matter. She would like to gain a better understanding of how well the students understood the lesson to help her plan for the next day’s activities. Which of the following activities is the most appropriate way for the teacher to evaluate student learning at the end of the lesson?

Administer an ungraded exit slip to each student with questions on the main concepts from the lesson. [An ungraded formative assessment is an appropriate way to evaluate initial student progress in a low-stakes setting.]

Which of the following options describe a “plant’s” response to an internal stimulus? Select ALL that apply.

• A dog panting on a hot day.

• A fox vomiting after eating a poisoned piece of meat.

An experiment in which students measure the time required for a marble to fall through columns of various liquids could be used to help them understand which of the following properties?

Viscosity. [Vicosity is a measure of a substance’s resistance to flow.]

Using the image below, which of the following statements correctly pairs Earth’s position with the reason for the observed season in the Northern Hemisphere?

The Northern Hemisphere experiences winter at Position 2, when it is tilted away from the Sun.

Which of the following statements correctly describes the motion of an object experiencing a net force to the right?

The object must be accelerating. [Any object experiencing a net force must be accelerating.]

Pine trees are a type of gymnosperm. Which of the following stages is responsible for the majority of photosynthetic energy production in pine trees?

The sporophyte. [The sporophyte phase, which refers to the tree itself, is responsible for the majority of the energy production.]

The following image above shows the relative locations of a water droplet and an observer, along with an incident ray of sunlight.

Which option below correctly describes the property or properties of light occurring at each location that make viewing a rainbow possible?

Location 1: dispersion and refraction; Location 2: reflection; Location 3: dispersion and refraction. [Dispersion and refraction occur when the light passes from one medium to another (air to water or water to air) and reflection occurs at the back of the droplet to redirect the light toward the observer]

Which of the following statements correctly explains a way in which populations change over time?

Selection requires phenotypic variation in a population. [For selection to occur, there must be physical variations among members of a population.]

A combustion engine in a car burns gasoline to power the movement of the car. Which of the following describes the types of energy transfers that occur in this process?

Chemical energy to heat energy and heat energy to mechanical energy. [When gasoline is burned, chemical energy is converted to heat energy and then the heat energy (and increase in pressure) is turned into mechanical energy in the driving of the pistons.]

Maria drinks several cups of coffee each day. She is experiencing symptoms such as a fast heartbeat, headaches, irritability, and restlessness. What is a scientific way that Maria can determine if her caffeine consumption is causing her symptoms?

Reduce the amount of coffee she drinks each day and reevaluate her symptoms. [By creating an experiment with the variable being caffeine, she can determine if that was the cause of her symptoms.]

A textbook includes an illustration of the water cycle, as shown below.

Which part of the water cycle is represented by the up arrow?

Evaporation. [Evaporation is going to come from the water and turn to a gas in the air.]

A teacher is planning a classroom activity to help students understand the concept of density. The teacher begins by placing various liquids in a glass jar. The liquids begin to layer themselves and separate in the jar. What should be the teacher’s next step to promote critical-thinking skills on this topic?

Ask the students to share ideas on why they think the liquids formed layers and ordered themselves. [In this step, the teacher is not giving the students the information. The teacher is asking the students to use the evidence they have to form a conclusion.]

Which of the following statements correctly describes a key way in which the outer planets differ from the inner planets in our solar system?

The outer planets are made of gas, unlike the inner planets.

A teacher created an assignment in which students were to keep track of plant growth under different watering conditions. The students recorded the amount of water each plant received daily and recorded the height of each plant weekly. Which of the following methods is the best way for the students to communicate their data correctly?

Create a graph showing each plant’s height and how much water it received. [

A science teacher has a class that includes several English language learners. He knows that he needs to adjust and adapt his instructional materials and plans to meet the needs of his limited-language students. What is the best action step for the teacher to take to help the students carry out their experiment independently?

Add descriptive pictures to the steps in addition to the wording. [If the issue holding the students back from independently working is reading and English, then adding pictures is the best option for aiding in the students’ comprehension of the steps.]

Molly places a metal spoon in her cup of hot cocoa. She reaches for the spoon and realizes that its handle is hot. Which scientific concept best explains why the spoon is hot?

Conduction.

Which of the following statements correctly describes Earth’s atmosphere?

The atmosphere is made up of several layers and protects Earth from some dangerous Sun rays.

Which of the following statements best explains why, as winters have become milder in Finland, the feathers of the tawny owls in the region have gradually turned browner?

The owls’ genetics are adapting their coloring to blend in with wooded areas rather than snow.

Use the list to answer the question that follows.

•  Can be seen without a telescope

• Smaller than the size of Earth

• Is a natural satellite

• Does not produce its own light

Which of the following types of celestial object is being described?

Moons.

Which of the following statements best explains how the structure of a cell membrane affects the function of the cell?

The cell membrane is semipermeable to allow some substances in and to keep others out of the cell. [The cell membrane is selective about what comes in and out. Its structure aids it in this function.]

Which of the following statements best explains how heat is related to weather and climate?

Uneven heating of Earth’s surface causes rising and falling of air. [The uneven heating causes wind, which ties to weather and climate.]

A class notices that the grass in an area near the air conditioner water runoff grows greener and taller than it does in other areas on the same side of the building. One student hypothesizes that grass grows better with more water. Which of these statements best explains why a student may choose this hypothesis?

The student noticed that the growth of the grass was a variable. [The growth of the grass was a variable, and the student was looking for a reason.]

Which of the following pairs of factors have the greatest impact on gravitational force?

Distance and mass. [The gravitational force depends on how much mass it has and how far it is from you.]

The food web above shows the interrelationship of various plants and animals within a particular ecosystem. Which of the following correctly compares the roles of the fox and the snake?

The fox and the snake are both strong predators in the food system because they are not prey for other animals.

An unheated pan of water is sitting on a stove burner. Which of the following best explains what happens to the pan when the stove is turned on?

The stove begins with potential energy, which transforms to kinetic. The pan heats up as the energy is increased.

At the end of the year, a science teacher wants to connect various concepts from the entire year for students. They have studied food webs, the makeup of the human body, the universe, and compound machines. What is the best unifying concept to tie these together?

Processes of systems, because all of the topics involve a system working together to function as a whole. [All the topics are made up of a system. Food webs are within ecosystems, the human body has organ systems, the universe has solar systems, and compound machines are made up of parts that work together to create a working system.]

A unit on friction could be used to help students make better decisions in which of the following situations?

Deciding how to drive on wet roads. [A better understanding of frictional forces may help the student understand why it is important to drive more slowly on wet roads.]

Scientists are looking for evidence of extinct animal species in a specific region to better understand the ecological history in the area. The types of evidence they hope to find are in the form of fossils, casts, or molds. In which of the following regions should the scientists focus their efforts?

On a hillside formed from primarily sedimentary rock. [Fossils, molds, and casts are primarily found in sedimentary rocks.]

In a unit on heredity, a teacher learns that many of the students believe that the dominant allele is always the most common allele for a gene. How can the teacher best address this misconception?

Use the information in the unit to confront the students’ misconception and then revisit the concept again later. [The teacher should show how the misconception does not align with the material within the unit to form a basis for their new understanding and revisit to ensure the real explanation is retained.]

The Nutria, a species of large rodent, was introduced to the United States from South America in 1889. Nutria were first farmed for their fur and then released to control the overgrowth of weeds. Nutria create burrows in the banks of lakes, rivers, and streams. Which of the following impacts on the local ecosystem are most likely to occur as a result of the introduction of the Nutria? Select ALL that apply.

• A decrease in the number of other rodent species in the ecosystem. [Native species can be threatened by invasive species that are able to out-compete native species for resources.]

• An alteration in the distribution of other species due to a change in available habitats.

• A disruption to the existing food web.

A teacher is preparing a class demonstration to illustrate the differences between physical and chemical changes to metallic elements. Which of the following types of demonstrations would be best for the teacher to perform to demonstrate a physical change associated with a metallic species? Select ALL that apply.

• Melting a piece of lead with a Bunsen burner

• Bending an iron rod

A science teacher has decided to assign a student work portfolio for one of the units in the upcoming semester. For which of the following purposes could the teacher best use such an assignment?

As a summative assessment to measure a student’s overall growth and ability at the end of the unit. [A portfolio can be used to measure overall student growth through a variety of work samples.]

Which of the following adaptations are most beneficial to cacti living in dry, desert climates?

Replacing leaves with spines reduces water loss from transpiration. [Reducing water loss is beneficial to the plants.]

Which of the following decisions could a student make that would directly reduce the negative effect on a non-renewable resource?

Walking to school instead of driving. [Limiting driving in turn limits the use of gas and oil, both non-renewable resources.]

In a unit on photosynthesis, a teacher is designing an activity in which the students will perform a set of experiments to learn about the photosynthetic process. The teacher would like the students to use the experiments to identify both the necessary ingredients for photosynthesis and the products created by photosynthesis. How can the teacher guide the experiments so each one allows the students to identify either an ingredient or a product of photosynthesis?

Grow plants in a sealed container with an oxygen sensor to identify a product. [Photosynthesis produces oxygen, which can be detected by an oxygen sensor.]

Which of the following events would be mostly likely to lead to a decrease in the temperature of Earth’s atmosphere?

The eruption of a supervolcano. [A supervolcano can eject particulates into the atmosphere and block solar radiation.]

A piñata hangs from a tree branch, supported by a single vertical string. The piñata is initially motionless (Point A). Then a child with a baseball bat hits the piñata, pushing it to the right (Point B). As the piñata moves to the right, the string breaks and the piñata falls to the ground (Point C). Which of the following statements correctly explains the forces acting on the piñata? Select ALL that apply.

• At Point B, the force on the bat is to the left. [The piñata experiences a rightward force, so the bat experiences a leftward force.]

• At Point C, the net force on the piñata is down. [The net force on the piñata will be the force of gravity.]

The image above shows the movement of a cold front across the United States. The weather characteristics in a region before and after the cold front arrives are also shown. Which of the following changes could be detected as the cold front moves past an area?

An increase in a reading on a barometer. [A barometer measures air pressure and would show an increased reading due to a rise in air pressure.]

Which of the following statements about inherited traits and learned characteristics are true? Select ALL that apply.

-Inherited traits originate in an organism’s DNA. [Inherited traits originate and are passed on through an organism’s DNA.]
-Learned characteristics develop over time. [Because learned characteristics are not present at birth, they are learned over time.]

A teacher assigns a project asking students to use scientific principles to develop a position on whether they should use refillable water bottles or single-use plastic water bottles. Which of the following would be acceptable project proposals? Select ALL that apply.

• Water-purity tests of bottled and tap water. [The purity testing will provide experimental data on the quality of water from the two sources.]

• A research paper on the environmental impact of plastic bottles. [A research paper can summarize scientific evidence on the effect plastic bottles have on the environment.]

A car travels down a country road at a constant speed. Then the driver sees a deer and gradually slows down to a complete stop. Each choice below includes a graph depicting the car’s position measured against time. Which graph most accurately describes the motion of the car?

The graph shows the car traveling at a constant speed and then slowing down and stopping.

Groundwater is a significant source of drinking water in the United States. Which of the following options correctly explains why the use of groundwater is generally seen as a safe source of drinking water? Select ALL that apply.

-Parasites and other harmful organisms are often filtered from groundwater as it passes down through the soil.

-Significant volumes of groundwater can exist, even in areas without large amounts of surface water.

A local forest service ranger informs a teacher that a significant die-off in amphibians is occurring in nearby wetlands. How can the teacher best use this event to help her students learn the process of scientific inquiry?

Allow the students to observe the wetlands and discuss their observations with the forest service ranger. [Allowing students to collect observational evidence and discuss it with the ranger will provide the students with an opportunity to develop and ask questions about the event.]

A sound wave passes from air to water. Which of the following will occur as it passes from one medium to the other?

The speed of the wave will change. [The medium (i.e., water vs. air) affects the speed of the sound wave as it passes through it.]

A species of corn can have kernels in one of seven different shades of orange and yellow. Two heterozygous parents create offspring with the following kernel color distribution:

What type of hereditary process will result in the observed kernel color distribution?

A single trait controlled by many different genes. [The combined input from multiple genes can create observed variety and pattern of kernel color in the offspring.]

Which of the following is a property of a gas?

.Compressibility. [The volume of a gas can be compressed.]

Which the following adaptations would best allow a species of mouse to create a new, beneficial niche in an area with few predators and several other ground-dwelling rodent species that forage at night?

A behavioral shift to forage in the early morning. [Shifting to a unique feeding time can reduce competition with other species.]

A new species is found in the Amazon, and the only available information so far is that it is multicellular and the cells have a cell wall. How can this information be used correctly to narrow down the possible taxonomic kingdoms for this species? Select ALL that apply.

-Use the multicellular evidence to rule out eubacteria.

-Use the cell wall evidence to add plantae to the list of potential kingdoms.

When planning a unit on plate tectonics, which of the following pieces of information would be most important for the teacher to take into consideration?

The students’ knowledge of the different layers of Earth. [This information is useful because plate tectonics are related to the different layers of Earth.]

Coastal locations are often known for having more moderate climates than inland locations during both the summer and winter. Which of the following factors contribute to the ability of coastal locations to lessen the extreme temperatures during summer and winter months? Select ALL that apply.

• In the summer, air above the land heats and rises more rapidly than the air above the ocean.[The rise of hot air above the land draws the cooler air above the ocean inland. This creates a cooling ocean breeze.]

• In the winter, the air above the ocean remains warmer than air above the land, causing it to rise.[The rise of air warm air above the ocean draws out cooler air over land, resulting in the circulation and warming of the air near the coast.]

• More energy is required to change the temperature of water than to change the temperature of land. [The heat capacity of water allows it to stay cooler than land in the summer and warmer than land in the winter.]

A student thinks that the measuring scale used in the lab may need to be calibrated. The student tests the scale by measuring a 7-gram weight three times. The student ensures that the scale is on zero before each weighing. The three measurements are 4 grams, 4 grams, and 3.9 grams. Which is a true statement about the scale measurements?

The measurements are precise but not accurate. accurate.][The measurements are precise because the three measurements were very close to being the same each time; however, they were not close to the actual value and therefore not accurate]

Which response to a student’s question will likely elicit the highest level of thinking?

Answering with a related open-ended question.

Through which of the following mechanisms does carbon enter living things in their cycle on Earth?

Photosynthesis. Carbon enters plants through photosynthesis, and then animals eat the plants.]

Which of the following statements correctly describe conservation of matter? Select ALL that apply.

• The amount of matter remains constant throughout physical and chemical changes.

• Chemical equations must be balanced so that the atoms on both sides of the reaction are the same.

• Parts in an object can be rearranged without affecting the amount of matter within the object.

During a science demonstration, a student uses a basketball, a softball, and a flashlight. The student demonstrates that when the softball is directly lined up between the basketball and the flashlight, the light is blocked. The student says that the basketball is Earth, the softball is the Moon, and the flashlight is the Sun. She states that the demonstration represents winter because the Sun is being blocked from Earth. Which statement best describes the student’s statement?During

The statement is partially correct; the Earth and Sun are represented, but the blocking of the light represents a solar eclipse. [The softball is the Moon passing between Earth and the Sun, creating a solar eclipse.]

Mack says that dandelions need rich soil to grow. Sam thinks this is incorrect because he noticed that dandelions were growing between the sandy cracks in the sidewalk. What process was Sam using to make this conclusion?

Logical reasoning.

Frogs in a rainforest
Cacti in a desert
Heart in a body
Grass in a prairie
Planets in the universe

Which of the following categories best describes the relationship between the items listed above?

Subsystems and systems.

Living things are made of cells. Which of the following characteristics has the greatest influence on the function of the cell?

Shape

What is the best explanation to describe food and chemicals being recombined to form living tissue and energy?

Chemical changes are taking place.

Foxes and owls both have a common need. They both hunt and compete for the same prey. What happens to the foxes and owls when they live in an abundant environment?

They will be able to coexist. [When the environment is abundant, little competition will take place.]

When a teacher adds a uniform white powder to water, some of the powder dissolves while the rest remains at the bottom. The addition of more powder has the same result—some dissolves, some remains. What type of substance is the powder?

Homogeneous mixture. [Homogeneous mixtures appear uniform and are able to be separated through physical means, like filtration.]

Which of the following phenomena causes the different phases of the moon as observed from Earth?

Changes in the moon’s location during its orbit around Earth. [The location of the moon during its orbit around Earth determines the phase of the moon visible on Earth’s surface.]

Question Number 25

A class studies an enzymatic reaction by measuring the conversion rate of substrate into products for a variety of substrate concentrations:

What conclusion should the teacher expect the students to make based on their data shown in the graph above?

The rate of the reaction is only dependent on the substrate concentration over a limited range. [The graph shows a change in reaction rate with respect to substrate concentration at lower concentrations only.]

A woman stands on top of a scale in an elevator that begins to accelerate upward. There are two forces acting on the woman, as shown in the following figure:

The scale measures the upward force on the woman. What will happen to the reading on the scale as the elevator begins to move?

It will increase because the net upward force increases the force between her feet and the scale. [The net upward force requires that the upward force be greater than the force of gravity.]

After submitting a manuscript on an exciting new result, a research student discovers the instrument he used was miscalibrated and the findings are likely incorrect. What course of action should the student take?

Contact the publisher to retract the paper immediately.

How can a teacher best create an inclusive environment for a hearing-impaired student while directing the class through the steps of an experiment? Select ALL that apply.

• Provide the student with a written copy of the directions.

• Stand close to the student when providing the class with directions.

• Demonstrate each step as it is verbally described to the class.

The hairless Sphynx breed of cat originated from a single, hairless offspring, born to parents with traditional fur. Hairless cats typically do not trigger allergic reactions in people. What process is the most likely explanation for the creation of the Sphynx breed of cats?

A random mutation followed by selective breeding. [The trait is desirable, and humans selectively breed further generations of hairless cats.]

A country is expecting to see a significant increase in the average age of its citizens over the next two decades due to a decrease in fertility and birth rates. What effect will the aging population likely have on this country?

• A shrinking workforce. [An aging population has a greater percentage of retired people and a smaller percentage in the workforce.]

• An increase in healthcare costs. [Older populations typically have more health concerns, which lead to greater healthcare costs.]

Part of the way through a unit on the conservation of energy, a teacher is worried that the students may not have the essential math skills needed for calculations within the unit. How can the teacher best determine if her concerns are valid?

Administer a performance assessment that focuses on the required math skills. [This method will allow the teacher to see if the students have the necessary math skills and to evaluate the areas in which they are having difficulty.]

Question Number 34

Day	Pressure	Pressure Change	Wind Speed
1	30.20	rising	1 miles per hour
2	29.80	falling	7 miles per hour
3	29.99	steady	2 miles per hour

According to the weather data collected in the table, what were the sky conditions most like on Day 2?

Overcast, precipitation, breezy. [The pressure is low and falling, and the wind is 7 miles per hour. Therefore, the weather is likely not good and getting worse.]

Which statement is a correct comparison of the inner and outer planets?

The inner planets are rocky, and the outer planets are gaseous.

Audio speakers need some form of electricity to work. However, Dan reads in a book that speakers operate using a magnetic field. What connection is there between electricity and magnetism?

Electric currents create magnetic fields that move, which cause electric currents to flow.

Which of the following processes on Earth is most directly responsible for volcanic activity?

Plate Tectonics

Which of the following statements best helps explain why offspring inherit traits from both parents?

Sox cells only have one set of 23 chromosomes. [Other cells in the body have two sets of 23 chromosomes. Sex cells do not, so the combining of the two would result in 23 from each parent.]

A pharmaceutical company has created a new drug to help people with heart defects but is unsure of the side effects the drug may have on people. The company decides to test the drug on rabbits to determine if there are any major negative effects. If no major effects arise, the company will further its testing of the drug. Which of the following statements is the strongest argument against the development of this drug?

Using animals as test objects is unethical.

What word best summarizes the difference between weather and climate?

Time. [Weather is measured over a short time period, and climate is measured over a longer time period.]

Which of the following statements best explains the connection between humans burning fossil fuels and the amount of polar ice?

The gases released from burning fossil fuels increase global temperatures. [The gases cause greenhouse effects and global warming, which in turn melt polar ice.]

A class is learning about human organ systems. The teacher wants the students to understand the route that food takes in the digestive system after it enters the mouth. Which activity would be most appropriate and effective for the lesson?

A computer simulation of food’s journey. [Because the students cannot experience the journey in real life, a simulation would be the next closest experience.]

The torpedo ray buries itself and blends into the sand. How is this an adaptive behavior for survival?

The rays use the sand to hide from predators. [By blending into the sand, the ray likely can hide from predators.]

A boy is playing a game at a school carnival. He is using a slingshot to shoot a ball at a target. If the target is hit with enough force, the target will fall and the boy wins a prize. Which statement describes how the boy can increase the energy of the ball?

The boy can increase the potential energy of the ball by pulling it back further in the sling, away from the target. When the ball goes into motion, it will have greater kinetic energy. [The potential energy would increase by pulling it further back in the sling, away from the target.]