TExES Science 7 - 12 Practice exam

The law that states that the magnitude of an electrostatic force between two points is directly proportional to the product of the magintude of each of the charges, and inversely proportional to the square of the distance between the charges is called which of the following?

Coulomb's Law. According to Coulomb's Law, the forces between two charged objects is equal to the product of the magnitude of their charges. That force falls off like most electromagnetic forces, with the square of the distance between the charges.

Which of the following organs is responsible for carrying food from the mouth to the stomach?

Esophagus The function of the the esophagus is to transport food through the digestive tract from the mouth to the stomach.

The next phase in the hydrologic cycle after ocean storage is which of the following?

Evaporation The water cycle step that follows ocean storage is evaporation. Water is then placed in atmospheric storage in preparation for precipitation.

According to Hooke's Law, restoring the force of a spring is directly proportional to the displacement. How can this be expressed in equation form if x denotes displacement?

F=- kx If x denotes displacement of spring deflection then mathematically Hooke's law can be expressed as F= - kx.

Middle altitude clouds occur between 2000 and 6000 meters. They are made up of ice crystals and water droplets because of colder temperatures. These middle altitude clouds are somewhat puffy, so they are called:

altocumulus. They are alto (mid-level) cumulus (puffy) False answers: cirrocumulus - high, wispy, puffy cloudsnimbostratus - very low, flat rain cloudsaltostratus - mid-level flattened

The figure shows four positively charged particles fixed in place. The net force on Q charge is zero. What is the Q/q ratio?

-2.(2)1/2

What is the name of the effect caused by intoxication as a result of ingesting alcohol?

Acute effect Acute toxicity results from a single, short exposure. Effects usually appear quickly and are often reversible. Chronic toxicity results from repeated exposure over a long period of time. Effects are usually delayed and gradual, and may be irreversible.

Which alkyl halide will have the maximum density?

CH3I CH3I has maximum density due to lowest carbon content and heavy halogen atom.

Earthquakes have always been difficult - if not impossible - to predict. It's still not possible to pinpoint locations, times, or magnitude of an earthquake. However, with modern GPS technology, it is possible to predict the probability of an earthquake by measuring:

stress accumulation When areas along a fault line don't move, stress builds up in the rocks. The longer this area hasn't moved, the more stress builds up and the more likely to a produce an earthquake. The other terms don't make sense here.

The picture above captures the last phase of the death of a star located in the constellation Cygnus the Swan. This very detailed picture is possible because it was taken in space, with no atmospheric interference, by a device which was launched in 1990 called:

the Hubble Space Telescope. (or HST)

Because numbers in science can be very large or very small, scientists often use a shorthand called scientific notation. For example, it is about 151 000 000 000 meters from the Earth to the sun. In proper scientific notation, that would be:

1.51 * 10^11 meters Both (a) and (b) are wrong because the forst number (coefficient) has to be between 1 and 10 (but not equal to 10). (d) is wrong because there are 11 places the decimal point has to move, not 9, to put it in the proper position.

What is the electric constant ε0 equal to?

1/(μ0c02) The electric constant ε0 equal to 1/(μ0c02), in which μ0, or the magnetic constant has the defined value 4π × 10−7 H m−1, and c0, which is the speed of light in vacuum, has the defined value 299792458 m s−1.

A roller coaster has a vertical loop that starts at ground level and reaches its highest point on the loop at 20 m. How fast in meters per second must a car of the roller coaster navigate the loop safely so that the passengers will experience a moment of weightlessness?(Assume that the loop is perfectly circular, and that g = 10 m/s2)

10m/s The centripetal acceleration of the cart and passengers must exactly balance the acceleration due to gravity, sov2/R = g. The radius of the loop is 10m and g = 10 m/s so v = 10 m/s.m/s = Meter(s) per seconds

Calculate the mean of these values 25 , 28 ,31 , 35 , 43 , 48.

35 How many numbers are there? 6. So, add together all of the numbers and divide the total by 6 in order to get the mean. Mean = (25 + 28 + 31 + 35 + 43 + 48)/6 Mean = 210/6 Mean = 35

The average ocean depth on Earth is about which of the distances listed below?

4000 meters. Averaging the deepest points which are about 10,000 meters, and the shallow continental shelf areas, the average depth of the ocean is about 4000 meters. This is equal to the grade difference of about 12,000 feet, or the distance from sea level to the top of a small mountain on land.

The equation for the dissociation of nitrous acid is HNO2 = H+ + NO2 - . If a solution of nitrous acid which is 0.0026N has a pH of 3, what is Ka for nitrous acid?

6.25 x 10-4. In the sample case, Ka = [H+][NO2 -] / [HNO2]. Also: [H+] = [NO2 -] = 10-pH = 10-3 = 0.001. In addition: [HNO2] = normality - [H+] = 0.0026 - 0.001 = 0.0016. Substituting values: Ka = (10-3 )( 10-3 )/(0.0016) = (1 x 10-4 )/(0.16) = 6.25 x 10-4.

How many grams of Na2SO4 is needed to prepare 10 dm³ of 8% solution (density ρ=1.075g/cm³)?

860g

Most electricity in the U.S. comes from energy moguls. In the past, some of those suppliers have conducted unethical scams to cheat the public. What would seem to be a better objective for the generation of electricity?

:A greater focus on conservation, efficient energy use, and renewable resources for the generation of electricity. There is a consensus that a greater focus on conservation, efficient energy use, and renewable resources for the generation of electricity is a good objective.

In the closest layer of the atmosphere to the Earth's surface (the troposphere), the air is usually warmer closer to the ground and generally decreases with increasing elevation. However, on a cold, calm winter night, the land rapidly cools, so the air near the ground can be colder than the air above it. This is referred to as:

A Temperature Inversion. A temperature inversion is an increase in temperature with greater elevation, not the usual decrease. A convection current occurs when warmer air rises through cooler air because it is less dense. This could be involved in a temperature inversion, but not in the example given. Jet streams are located in the stratosphere. A stationary front occurs when a warm and a cold air mass meet and neither one moves.

What substance can be described as containing two or more chemical elements held together by chemical bonds?

A compound. That is normally part of the definition of a compound. Components of either a homogeneous or heterogeneous mixture will not be chemically bonded. An atom is the smallest unit of an element that maintains the element properties. It cannot be composed of more than one element.

What is an example of acid salt? NaHSO3 NaH2PO4 NaHCO3 All of the above

All of the above All contain replaceable hydrogen and are acid salts.

What is the advantage of hydro-power generation?

All of the above As hydro power generation involves no fuel (water abundantly available). This is one of the cheapest sources of power production. As there is no reaction involved, there is no gas production Dam can store huge amount of water, so that they can handle big load. The Load Factor for Solar and Wind Energy ranges from 15-40% which is quite low compared to Fossil Fuel Energy. Hydroelectricity on the other hand has a load factor of almost 40-60%.

Which of the following are considered abiotic factors in the distribution of organisms? Temperature Water Wind All of the above.

All of the above. Temperature's main importance is its effect on an organism's metabolism. Water is essential to life, and the varying ability of an organism to obtain and retain water is an important factor in their distribution. Wind can have an effect on an organism's distribution when it amplifies the effect of temperature (for example, wind chill) or when the mechanical pressure of wind has an effect on the morphological structure of plants. Light, soil, and environmental disturbances are also abiotic factors affecting distribution. The correct answer therefore, is (D).

Latia is running a one-mile run. When she gets to the third lap, she starts to slow down, and her muscles do not work as effectively. Her coach tells her that it is because her muscles do not have enough oxygen and are now doing which of the following?

Anaerobic respiration. When Latia's muscles run out of oxygen on the third lap, her muscles are forced to run on anaerobic respiration. This is respiration without oxygen, and it is about 1/10th as efficient as oxygenated (aerobic) respiration.

Which of the following is the first stage the human population goes through on its way to reach full demographic transition?

Birth and death rates are both high. Basic sanitation and medicine are not available to lengthen life span. This is the first step the human population goes through on its way to stabilization in the demographic transition model. Full demographic transition is reached when the population becomes stable and birth rates equal death rates.

What is the name of the artery in the upper arm that is occluded when blood pressure is measured?

Brachial The brachial artery is traditionally occluded using a blood pressure cuff. As the pressure in the cuff is slowly released, the pressure at which the sound of blood flow is heard is noted and represents the systolic blood pressure. The pressure at which blood flow can no longer be heard in the artery is recorded as the diastolic blood pressure. The correct answer therefore, is (A).

What vitamin deficiency leads to scurvy?

C Scurvy is caused by a lack of ascorbic acid or vitamin C. It is critical for the formation of collagen. A major source of vitamin C comes from citrus fruits which were sometimes carried on ships for long voyages to prevent the disease.

In which of the following ways do bryophytes transport water and minerals?

Diffusion In bryophytes, there are no water-conducting or nutrient-conducting structures and the transport of these substances is carried out via cell to cell diffusion.

Population growth usually does not continue forever. One major factor that balances population growth is which of the following?

Disease. Disease usually has a profound effect on population growth when it becomes too high to sustain a population in one area. Disease can cause a very rapid decline in population growth in a very short time period.

What term is used to describe when an author or publisher prints the same printed material more than once?

Duplicate publication Duplicate publication, multiple publication, or redundant publication refers to publishing the same intellectual material more than once by the author or publisher.

Viruses that cause cancer are called what?

Oncoviruses Viruses that can cause cancer in animals are called oncoviruses, a term that is synonymous with "tumor viruses". Cells become transformed into cancer cells when viral nucleic acid becomes integrated into host DNA.

A seed is a(n) what?

Embryo with its food supply contained in a protective coat Plants with seeds evolved late in the Devonian period, around 360 million years ago. A seed is an embryo with its food supply contained in a protective coat and became an important means for plants to disperse offspring.

What physical property is a measurement of the capacity to do work?

Energy. Energy is a measurement of the capacity to do work. Energy is the currency for work. It can be found in different forms (i.e. potential, kinetic, chemical, electrical, etc.)

A researcher puts meat in two different jars. One jar he covers with gauze and the other jar is left uncovered. Several days pass and maggots appear in the uncovered jar, while there are no maggots in the jar covered with gauze. Which of the following is the manipulated variable?

Gauze A hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled. The variable that is deliberately changed, in this case the guaze, is called the manipulated, or independent variable. The variables that are observed and that change in response to the manipulated variable is called the responding variable.

Who is considered by most to be the Father of the Modern Science of Genetics?

Gregor Mendel

Which pair of atoms would form a nonpolar covalent bond?

H-H Nonpolar covalent bonds are formed when the bonding electrons in the outer shell are equally shared between atoms. That occurs whenever two of the same atom types join together, or when hydrogen and carbon bond together. All other forms of covalent bond are polar covalent bonds.

Identify the decomposition reaction.

H2SO4 → H2O(l)+ SO3(g) Few acids on heating, decomposes to form water and metallic oxides. Here, sulfuric acid decomposes to form water and sulfur/sulphur trioxide. The options A, B and D are examples of replacement, synthesis and hydrocarbon combustion reactions, respectively.

Stomatal closing might help a plant survive what type of environmental stress?

Hot, dry weather Plants use a process called transpiration to create evaporative cooling. In hot, dry conditions plants may take advantage of mechanisms that help to reduce transpiration and thus conserve water. Guard cells lose turgor and stomata close.

Which characteristics of covalent compounds makes them poor conductors of heat? Characteristic 1: They do not have free electrons. Characteristic 2: There is a lack of electrical charge in covalent molecules. Characteristic 3: Covalent structures have large gaps between molecules.

I and II only Characteristics I and II are quite similar. Because covalent bonding involves the sharing of all of the electrons between molecules, all free electrons are removed. The electrical charge associated with free electrons thereby, is removed. The bond physical length has much more to do with their strength, and less to do with the conductive properties.

A type of technique that produces an image from several telescopes is called

Interferometry A process called interferometry helps improve the resolution of images that have been converted from data by a computer. Interferometry uses the images from many telescopes to generate one image.

This is a diagram of the digestive system of an earthworm. What part is represented by D ?

Intestine Starting with the mouth opening at the anterior end, the first area is a muscular pharynx, where food is ingested. This is followed by a tube-like esophagus which terminates in a crop which serves as a storage stomach. After the crop you will find the gizzard. The gizzard is followed by a long intestine. Digestion and absorption occur in the intestine.

What will happen to the bond energy of heterodiatomic molecules with a decrease in electronegativities of bonded atoms?

It decreases. The bond energy of hetero diatomic molecules decreases with the decrease in the difference of electronegativities of the bonded atoms. This is due to decrease in polarity and decrease in the bond length

Which statement is correct about ionic product of an electrolyte?

It is less than, equal to, or greater than solubility product. Ordinarily, ionic product is less than or equal to solubility product. However, for supersaturated solutions ionic product is greater than solubility product.

If 'I' represents moment of inertia and 'ω' stands for angular velocity, what equation is the mathematical expression of rotational kinetic energy?

KEr = ½ I ω2 The mathematical expression of rotational KE comes from angular velocity and moment of inertia, and this expression is KEr = ½ I ω2 when it gets fixed axis of rotation.

When creating an assessment, teachers should:

Keep time limits in mind When creating assessment, teacher should keep time limits in mind. Teachers should determine how much time they are willing to create the assessment as well as how long they will allow for their students to take the assessment.

Which of Kepler's Planetary Laws of Motion is a statement of the conservation of angular momentum?

Kepler's Second Law Kepler's Second Law states that, "A line joining a planet and the sun sweeps out equal areas during equal intervals of time." Symbolically, d/dt(½r2θ)=0, ½r2θ, or a real velocity is proportional to the angular momentum, and for the same reason Kepler's Second Law is also a statement of the conservation of angular momentum.

Which of the following fundamental scientific laws could be defined by "opposites attract"?

Magnetism The like poles of different magnets repel each other and the unlike poles attract each other.

The Kaibab Limestone layer, seen above as the highest and most recent rock layer in the wall of the Grand Canyon, is also found more than 60 miles away at the bottom of Zion National Park in Utah. This is determined by a method called correlation. Correlation is the:

Matching of unique rock outcrops or fossils exposed in one geographical area to similar outcrops exposed in other geographical areas. Correlation is an attempt to compare rock layers laid down at the same time in different geographical areas. Even though correlation suggests separation, it really doesn't focus on the separation of different rock layers. Many different rock layers could be made up of the same kind of sedimentary rock - th

Friedrich Mohs was an Austrian scientist famous for which geological discovery?

Mineral hardness. Friedrich Mohs developed a Mohs scale to evaluate the hardness of minerals. The scale rating ranges from 1 to 10. Diamond, the hardest mineral evaluated, is at the top of the scale, with a rating of 10, while Talc, the softest mineral evaluated, is at the low end of the scale with a rating of 1.

What is the conjugate acid of ammonia?

NH4+ The ammonium ion, NH4+ is the conjugate acid of ammonia. All amino acids have an NH2 group that can be protonated at low pH to become NH3+ which could be considered one of the conjugate acids of that amino acid. Conjugate acids are formed when a weak base takes on a hydrogen io

Identify the chemical compound also known as "laughing gas" or "sweet air".

Nitrous oxide Nitrous oxide (N2O) gas is a light sedative and usually used in dentists' offices.

Moore's Law states that the number of transistors that can be placed inexpensively on an integrated circuit board has increased exponentially, thereby doubling approximately every two years. That Law has worked every year since 1958, but can Moore's Law be maintained indefinitely?

No Because of physical constraints, exponential growth can never be maintained indefinitely. Even Moore's Law is subjected to theoretical limits.

Movement along this type of fault is partly horizontal and partly vertical. The horizontal movement pulls the rock apart and stresses the crust.

Normal Fault False answers: Reverse fault - compression as they plates move toward each other causes horizontal and vertical movement. Strike-slip fault - caused by horizontal shear Shear - same as strike-slip

This type of organism must use oxygen for cellular respiration and cannot grow without it.

Obligate aerobes Organisms can vary in their requirements for oxygen and the effect that oxygen has on their growth. Obligate aerobes use oxygen for cellular respiration and cannot grow without it. Almost all animals, most fungi, and several bacteria are obligate aerobes.

Based on the image above, which of the following represents a type of low cost fuel used for energy?

Peat Peat is a spongy, organic material that is a fossil fuel. Further, peat is made from moss and other bog plants. Peat is considered a low cost fossil fuel since it can be easily processed and sold.

Tiny microscopic organisms at the base of the marine food chain are called

Phytoplankton Phytoplanktons are microscopic organisms at the base of the marine food chain. They were abundant during the Cretaceous period. Many white chalk deposits around the world hold their shell-like hard parts. England's White Cliffs of Dover is made up of fossil remains of phytoplanktons.

Which of the following is NOT a blood cell? 1. Thrombocytes 2.Plasmacytes 3.Leukocytes 4.Erythrocytes.

Plasmacytes. Blood cells include erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets). Plasma is a clear liquid that is 90 percent water and carries the blood cells.

Marie Curie was awarded a Nobel prizes in 1911 for her work in the field of chemistry. What did she discover?

Polonium and radium Marie Curie worked in a shed behind the Sorbonne University. This was her laboratory. She isolated Polonium, a new element, and named it after her homeland Poland. To isolate radium she started with tons of pitchblende, an ore that contains uranium. It took her four years to isolate a 0.1 gram of radium chloride. She named it for the "rays" it emitted.

The process through which water in its various forms falls to the earth under gravity is which of the following?

Precipitation Precipitation is the process through which water in forms such as rain, sleet, snow and hail falls from the sky to the earth.

A satellite is an object acting on the force of gravity and moving around the earth. What can be compared to a satellite?

Projectile Most basic thing to understand satellite is that it can be compared with a projectile, and upon it the only acting force is gravitational force. Newton theorized that a projectile launched with sufficient speed would start orbiting the earth.

Hard parts of a prehistoric object are changed and preserved through which of the following?

Recrystallization Besides mineral replacement, hard parts of organisms are changed and preserved through recrystallization. The process of recrystallization happens when a buried hard structure of an organism has a change in temperature and pressure. As a result, the original mineral of the hard part is changed into a new mineral.

If a student is unsure about how a valid science procedure works, and believes it has an invalid conclusion, what is the best thing for teachers to do?

Show students how to properly take steps in finding the valid conclusion If a student is not getting a correct conclusion, teachers can show students how to properly take steps in finding the valid conclusion. Teachers should be ready and willing to help students effectively learn in the classroom.

The term for the membranous network that synthesizes lipids and carbohydrates (labeled # 8 in the diagram above) is which of the following?

Smooth endoplasmic reticulum The smooth endoplasmic reticulum is the membranous network that synthesizes lipids and carbohydrates. The rough endoplasmic reticulum (labeled # 5) is also a membranous network, but it receives and transports synthesized proteins. The Golgi apparatus, also known as the Golgi body, (labeled # 6) chemically processes and packages substances from the endoplasmic reticulum. The lysosome, labeled # 12, acts as the cell's "digestive system."

The physical and chemical composition of soil affects its ability to allow water to pass through or to be absorbed. Which of the following soils would be LEAST able to hold water or allow it to pass through?

Soil with a high percentage of clay. Clay particles are small, so the amount of space between the particles is small. Water molecules have a more difficult time penetrating through them. The other soils either absorb water more than clay (humus) or penetrate quickly (sand or large particles).

There were several methods, besides looking at maps, that Wegener used as evidence for his theory. One of those methods was looking at fossils. The evidence from fossils was:

Some large land-dwelling creatures have fossils found on continents separated by water today; they could not have swum large distances in the past. The inverse ("No fossils of any large land-dwelling creatures are found on any continent; they could not have existed until after the continents divided") of the true statement cannot also be true. Fossils of large animals have been found on both sides of the Atlantic Ocean. Both similar plant AND animal fossils have been found, He didn't ignore the evidence.

Which of the following is demonstrated by the passing of white light through a prism?

That white light is actually a mixture of different colors When white light shines through a prism, it is refracted, which demonstrates that the white light is actually a mixture of colors.

Meteorites are sometimes used as evidence of the age of the Earth and the age of the Solar System. According to radiometric dating that has been done to meteorites and the oldest rocks from the Earth, both kinds of rock have approximately the same age. What does this finding suggest?

The Solar System formed at about the same time that the Earth formed. No matter how old the Earth and the Solar System are, the logical conclusion from the data is that they are the same age. If the Solar System were twice as old, meteorites should be dated as twice as old as the Earth rocks. And if the Earth is twice as old as the Solar System, meteorites should be twice as young, not the same age. A conclusion can be drawn from the data, even if someone would disagree with the absolute age calculation.

When a billard ball is bounced off the boundary of a billard table, the angle of reflection is equal to which of the following?

The angle of incidence. The angle of incidence is equal to the angle of reflection. The billard ball will bounce off the border, and roll back at the same angle in which it hit the border.

Carbon dioxide is a variable gas in the Earth's atmosphere that has been gradually increasing over the past 150 years since measuring it has been possible. The amount of carbon dioxide in the atmosphere is believed to be causing global warming. Which of the following probably is the most abundant source of carbon dioxide in the atmosphere?

The burning of fossil fuels to heat building, produce electricity, and power vehicles. While man-made global warming has not been proven (in fact, there is proof that some of the data in untrue), adding carbon dioxide to the atmosphere could have the effect of preventing the sun's heat from escaping, thus raising the overall temperature of the Earth's surface. Carbon dioxide, however, is also used by plants to do photosynthesis, so the effect of increasing it could be seen as favoring plant growth. The amount of carbon dioxide released by respiration is not considered significant enough to cause any changes. Dying and decaying plants primarily release ammonia and methane into the atmosphere, but carbon compounds are released into the soil. The sun's ultraviolet radiation produces ozone from oxygen in the upper atmosphere, and converts nitrogen-14 to Carbon-14, but it doesn't have much effect of producing carbon dioxide.

As the Earth orbits the sun, nearby stars appear to move in relation to background stars. The diagram above shows why this shifting of position occurs. This shifting is known as parallax, and the general rule is:

The closer the star, the larger the shift. The opposite (the closer the star, the smaller the shift) cannot also be true. The distance to a star does have a relationship to its shifting. And closer stars move more than more distant stars.

What is the electrochemical gradient?

The forces that work on an ion as a result of the different charge inside a cell and outside a cell The cytoplasm of a cell is negative in charge compared to the extracellular fluid. This is due to an unequal distribution of anions vs. cations on opposite sides of the cellular membrane. This combination of forces working on an ion is called the electrochemical gradient.

Chemical weathering is affected by climate. In which of the following climate would chemical weathering be the most rapid?

The warm temperatures, abundant rainfall, and lush vegetation of the Amazon rainforest. The conditions encourage chemical reactions. False responses: The temperate climate of the American Northeast - warm, humid summers; cold, snowy winters - moderate effect. The hot, dry climate of the American Southwest - preserves things better. The cold, snowy climate of Northern Canada - rate of chemical weathering the least.

In regards to assessments inside the classroom, each assessment has what?

Their own set of strengths and weaknesses based on the assessment. In regards to assessments inside the classroom, each assessment has their own set of strengths and weaknesses based on the assessment. Assessments are not all the same, and can be used for different reasons.

Energy cannot be created or destroyed, but only transferred from one form to another form. When fuel is combusted into a vehicle's engine, its chemical energy is converted into two (2) different forms. Identify the converted forms of energy used to run the vehicle.

Thermal and Mechanical When fuel is combusted in to a vehicle engine its chemical energy is converted in to Thermal and Mechanical energy, which aids to run the vehicle.

How many Faradays are required to reduce one (1) mole of Ni+2 to Ni(s)?

Two (2) Faradays. One mole of Ni2+ requires two (2) moles of electrons to change to Ni(s). The transfer of one mole of electrons is equivalent to one (1) Faraday. Two (2) Faradays therefore, are needed.

Ultisols, as in the soil shown above, are found in the American Southeast. Which of the following statements is NOT true of ultisols.

Ultisols have a high organic matter content. Ultisols are strongly leached, acid forest soils. They are found in humid temperate and tropical areas. Ultisols have a subsurface horizon in which clays have accumulated due to the presence of iron oxides. They are dominant in the southeast US. Mollisols are the soils of grassland ecosystems which have a high organic matter content.

Which polymer can be used for making unbreakable cups and laminated sheets?

Urea formaldehyde resin Bakelite formed using phenol and formaldehyde is used for making combs, electrical switches, handles of utensils and computer discs. Neoprene is used in laptop sleeves, orthopedic brace, liquid and sheet applied elastomeric membranes or flashings, and car fan belts. Polystyrene is used in disposable cutlery, plastic models, CD and DVD cases, and smoke detector housings. PVC is clothing and upholstery, electrical cable insulation, inflatable products Basic durability property of Urea formaldehyde resin is used for making unbreakable cups and laminated sheets. Other polymers don't show this property. Hence, D is the correct option. Report a problem with this question

Which of the following is considered to be poor hygiene while performing experiments in a laboratory?

Use laboratory glassware for eating or drinking purposes Laboratory glassware may contain toxic substances in it, while you will use them for drinking purpose then may orally ingesting a toxic substance through this glassware .

Which of the following persons proposed that new cells arise only from previously existing cells, thus disputing the idea of spontaneous generation?

Virchow In 1858 Rudolf Virchow proposed that new cells arise only from previously existing cells, thus disputing the idea of spontaneous generation. Hooke studied nonliving cells. Leeuwenhoek was the first to see bacteria from teeth scrapings and animals-like protists from pond water, and Schleiden worked with plants and noticed that all plants are made of cells.

When a large, solid, metallic sphere is heated slowly, where does the largest percentage increase occur?

Volume When the sphere is heated the diameter, volume and surface area increase. Since the mass is unchanged the density decreases. The percentage change in volume in the largest as the coefficient of volume expansion is greater than the coefficient of linear expansion and area expansion.

What relationship can be explained using the process of breathing?

Volume and pressure During exhalation, the volume of thoracic cavities is reduced, pressure in lungs increases, and we exhale. During the inhalation, we have the opposite case.

The last symbol on the chart signifies which of the following?

Wavelength. The lambda (Greek) symbol signifies wavelength. Wavelength is the distance from one part of a wave to the corresponding part on the next wave.

If the atmosphere were twice as thick as it is now, would your weight be higher or lower than your current weight?

Weight would be lower. Your weight is determined by gravity, but a heavier atmosphere would cause you to be more buoyant. According to Archimedes' Principle, your weight would be lower.

A 7th grade science teacher is developing a performance assessment. What should he decide before he creates it?

Whether to measure both or either product or processes. Before a teacher creates an assessment, they should decide whether to measure both or either of the product or processes. Teachers should thoroughly think about what they want from an assessment, and develop it from those needs.

A collision of two air masses is called a front. When cold, dense air displaces warm air, the warm air mass is pushed up, condenses, often causing violent storms. What type of front is this?

a cold front. False answers: An occluded front - one cold air mass overtakes another. Stationary front - warm mass meets a cold mass Warm front - a warm air mass rises over a cold one.

A star that begins with a mass between about 8 to 20 times the Sun's mass will end up with a core that is too massive to be stable or to be held together by electron pressure. A star like this will collapse and become an extremely dense star remnant called;

a neutron star.T They are extremely dense. False answers: a main sequence star - average, like the Sun a quasar - luminous galaxies that give off radio waves a binary star - a cluster of two stars.

The sun, pictured above, sends both light and heat radiation down to the Earth. The type of electromagnetic radiation that reaches the Earth as heat energy (and is also emitted back into space) is:

infrared. Infrared radiation is heat radiation. False answers: ultraviolet - above violet; more energetic microwaves - below infrared. visible - above infrared

Metamorphic rocks are usually classified into two groups: foliated and nonfoliated. Slate, shown above, is a foliated rock, which means:

it is formed from minerals that have flat or needle-like crystals into parallel layers. Foliated metamorphic rocks are formed from minerals that have flat or needle-like crystals into parallel layers. Slate is an example. Nonfoliated rocks are composed of minerals with more block-shaped crystals. Metamorphic rocks can melt and refreeze, but they wouldn't be foliated if they had a haphazard pattern. Exfoliation is the process of peeling off rock layers, but the pieces don't form foliated rocks.

All of the following types of macromolecules are very long molecules made of the same repeating type of building block EXCEPT:

lipids Carbohydrates, proteins, and nucleic acids are long, repetitive molecules called polymers. A polymer is made out of a building block called a monomer. Lipids are more diverse in structure than the other 3 macromolecules and are not polymers.

As sediment was deposited in the past, the more that was deposited, the greater the heat and pressure on the bottom layers. The physical and chemical processes that turned those sediments into sedimentary rocks is called:

lithification Lithification means "the process of making stone". False Answers: erosion: the process of producing layers of sediment. intrusion - the insertion of magma through cracks underground, slowly cooling to become rocks. extrusion - magma emerging as lava in the air, then cooling to form rock.

The Moon, as pictured above, has features that, to many living on Earth, make it look like a face. The "man in the moon" is actually caused by light-colored lunar highlands and dark, smooth regions with very few craters called:

maria. Maria (plural of mare) are so-called because they looked like seas to ancient people - the Latin word for seas is "maria". Ejecta is material that was blasted out of the Moon's surface when meteors hit and produced craters. Rays are long trails of ejecta that radiate outward from a crater. Rilles are meandering, valley-like structures that may be collapsed lava tubes.

Which of the following terms describes all the chemical substances that an organism needs to sustain life?

nutrients All the chemical substances that an organism needs to sustain life are its nutrients. Every living organism needs nutrients to build tissues and carry out essential life functions. Like water, nutrients are passed between organisms and the environment through biogeochemical cycles.

A clown fish is taken from a saltwater tank and put into a freshwater tank. Shortly thereafter the clown fish dies. Which of the following describes what has happened to the clown fish?

osmosis Clown fish have extra salt in their cells to slow down the process of osmosis from the cells to the saltwater outside the cells. If you put the clown fish in a freshwater tank, the water is too hypotonic and osmosis will keep bringing water into the cell until the cell bursts and dies.

An element is characterized by having a certain number of which of the following in its nucleus?

protons The number of protons always determines which element the atom is. The number of electrons and neutrons can matter for other things, but for determining which element the atom is, only protons matter.

A type of telescope that has lenses to collect light is known as?

refracting telescopes. There are two types of telescopes that scientists use to focus viewable light: the refracting telescope and the reflecting telescope. The refracting telescope uses lenses to focus the visible light.

Which of the following materials is NOT a conductor of electricity?

rubber All of the materials listed are conductors of electricity except rubber.

When light moves from a medium with a higher refractive index n1 to one with a lower refractive index n2, what is the critical angle?

sin-1(n2/n1) Total internal reflection occurs when a ray of light moves from a medium with a higher refractive index to one with a lower refractive index. At a particular angle called the critical angle and at incident angles larger than it the incident ray does not move into the second medium but stays in the first medium. The critical angle can be found by the expression: sin-1(n2/n1)

A blood vessel carrying blood away from the heart is lined with which of the following types of muscle?

smooth muscle The only type of muscle that lines a blood vessel or artery is smooth muscle.

The phenomenon that occurs when electric charges build up on two objects that have been pulled away from each other is called

static electricity When two objects, such as a balloon and a head of hair, are rubbed against one another and pulled away from each other, static electricity results.

According to the First Law of Thermodynamics, identify the equation for the following: amount of energy added to the system by a heating process (δQ), the amount of energy lost by the system due to work done by the system on its surroundings (δW), and the change in the internal energy of the system (dU).

δU=δQ+δW For a thermodynamic system with a fixed number of particles, the first law of thermodynamics may be stated as: δU=δQ+δW, where δQ is the amount of energy added to the system by a heating process, δW is the amount of energy lost by the system due to work done by the system on its surroundings and δU is the change in the internal energy of the system.