ACT Science Exam 4

1. A child falls down and punctures his skin. What biological process must occur to repair the damaged skin?

Glycolysis

Cell Respiration

Gluconeogenesis

Cell Reproduction

D. Cell reproduction is the process where cells grow and differentiate to create offspring or new cells. When the skin is damaged, new skin cells are needed which are created through cell reproduction. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

Explanation

D. Cell reproduction is the process where cells grow and differentiate to create offspring or new cells. When the skin is damaged, new skin cells are needed which are created through cell reproduction. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

2. In which state of matter are the intermolecular forces between particles in a substance the strongest?

Gas

Liquid

Plasma

Solid

D. In solids, particles are usually closer together than in other states of matter because of the strong cohesive forces between the particles. See Lesson: States of Matter.

Explanation

D. In solids, particles are usually closer together than in other states of matter because of the strong cohesive forces between the particles. See Lesson: States of Matter.

3. A reporter on the scene of an approaching hurricane notes that a pier has on one of its piles a large vertical ruler marked in feet. She uses it to measure ocean waves as they approach shore, finding that the waves are reaching as high as 12 feet and as low as 3 feet. What is the peak-to-peak amplitude of these waves?

4.5 feet

9 feet

12 feet

15 feet

B. The peak-to-peak amplitude is the distance between the crest and the trough. That distance is the difference between the measured heights of the crest and trough on the ruler: 12 feet – 3 feet = 9 feet.

See Lesson: Waves and Sounds.

Explanation

B. The peak-to-peak amplitude is the distance between the crest and the trough. That distance is the difference between the measured heights of the crest and trough on the ruler: 12 feet – 3 feet = 9 feet.

See Lesson: Waves and Sounds.

4. Several participants are enrolled in a study that is evaluating the effectiveness of new drug targeted at slowing the progression of breast cancer. Some participants are asked to take the new drug and monitored over a six-month period. Others are asked to take a placebo. They are also monitored over six months. What is the dependent variable?

Drug

Condition

Placebo

Time

B. The independent variable is the administered drug because it is being manipulated in the experiment. The condition, following treatment with the drug, is the dependent variable. Condition is a type of response that is dependent on the drug being administered. See Lesson: Designing an Experiment.

Explanation

B. The independent variable is the administered drug because it is being manipulated in the experiment. The condition, following treatment with the drug, is the dependent variable. Condition is a type of response that is dependent on the drug being administered. See Lesson: Designing an Experiment.

5. The amount of heat that has been removed from the substance allows the particles to draw closer together, and the material changes from a liquid to a solid. Which of the following is being described?

Condensation

Deposition

Freezing

Sublimation

C. Freezing is the change of a liquid to a solid. See Lesson: Properties of Matter.

Explanation

C. Freezing is the change of a liquid to a solid. See Lesson: Properties of Matter.

6. What is the name for Earth's outermost layer?

Core

Crust

Center

Mantle

B. The crust is the outermost layer of Earth. See Lesson: Geology.

Explanation

B. The crust is the outermost layer of Earth. See Lesson: Geology.

7.

(–12, 6)

(–12, 18)

(–1, 6)

(–1, 9)

Explanation

8. Which organelle is DNA found in?

Nucleus

Ribosome

Mitochondrion

Endoplasmic reticulum

A. The nucleus is a membrane-bound organelle found only in eukaryotic cells. It contains the genetic information for a cell, or DNA. See Lesson: Cell Structure, Function, and Type.

Explanation

A. The nucleus is a membrane-bound organelle found only in eukaryotic cells. It contains the genetic information for a cell, or DNA. See Lesson: Cell Structure, Function, and Type.

9. What are giant stars?

Stars that are very small and dim

Stars that are in their longest stage of life

Stars that are very large and brighter than the sun

Groups of stars and star systems that are bound together by gravity

C. Stars that have very large radii and are brighter than the sun are called giant stars. See Lesson: Astronomy.

Explanation

C. Stars that have very large radii and are brighter than the sun are called giant stars. See Lesson: Astronomy.

10. A student notices a pattern of stripes on five tigers. Each of the five tigers has the same stripe pattern. Using his inductive reasoning, what does he logically assume based on this information?

The pattern continues to change over time.

Natural adaptations cause this pattern to occur.

Each offspring will have the same stripe pattern.

Ancestors of the tigers have different stripe patterns.

C. Inductive reasoning involves making specific observations and using them to make broad statements. The student observes that all of the tigers have the same stripe pattern. He can use this observation to make the broad statement that all the tigers’ offspring will have the same stripe pattern. See Lesson: Designing an Experiment.

Explanation

C. Inductive reasoning involves making specific observations and using them to make broad statements. The student observes that all of the tigers have the same stripe pattern. He can use this observation to make the broad statement that all the tigers’ offspring will have the same stripe pattern. See Lesson: Designing an Experiment.

11. How many meters are equivalent to 45.5 kilometers?

450

4500

45500

455000

C. One kilometer is equal to 1,000 meters. This means multiplying 45.5 by 1,000 yields 45,500 meters. Moving the decimal to the right (according to the metric staircase) also gives the value of 45,500 meters. See Lesson: Temperature and the Metric System.

Explanation

C. One kilometer is equal to 1,000 meters. This means multiplying 45.5 by 1,000 yields 45,500 meters. Moving the decimal to the right (according to the metric staircase) also gives the value of 45,500 meters. See Lesson: Temperature and the Metric System.

12. What organelle plays a role in assembling subunits for protein synthesis?

Cytoplasm

Flagellum

Lysosome

Nucleolus

D. The nucleolus is found in the nucleus and aids in protein synthesis. See Lesson: Cell Structure, Function, and Type.

Explanation

D. The nucleolus is found in the nucleus and aids in protein synthesis. See Lesson: Cell Structure, Function, and Type.

13. What is the correct order of phases in mitosis?

Telophase, metaphase, prophase, anaphase

Prophase, metaphase, anaphase, telophase

Metaphase, anaphase, prophase, telophase

Anaphase, prophase, metaphase, telophase

B. After the cell cycle occurs during interphase, the cell begins the M phase, or mitosis. Mitosis starts with prophase and proceeds to metaphase. Once chromosomes separate during anaphase, new daughter cells are formed during telophase. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

Explanation

B. After the cell cycle occurs during interphase, the cell begins the M phase, or mitosis. Mitosis starts with prophase and proceeds to metaphase. Once chromosomes separate during anaphase, new daughter cells are formed during telophase. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

14. What is the function of a centromere?

To connect the two chromatids

To keep the chromosome stable

To act as a relay point for genetic information

To transmit genetic codes between other chromosomes

A. The protein disc that connects the two chromatids is the centromere. See Lesson: Genetics and DNA.

Explanation

A. The protein disc that connects the two chromatids is the centromere. See Lesson: Genetics and DNA.

15. Which of the following are the three main phases of the water cycle on Earth?

Evaporation, condensation, glaciation

Evaporation, absorption, precipitation

Evaporation, condensation, precipitation

Assimilation, condensation, precipitation

C. The three main phases of the water cycle on Earth are evaporation, condensation, and precipitation. See Lesson: Meteorology.

Explanation

C. The three main phases of the water cycle on Earth are evaporation, condensation, and precipitation. See Lesson: Meteorology.

16. What is the momentum of a golf ball with a mass of 45.9 g moving at 81 m/s in ?

1.4

2

3.3

3.7

Explanation

17. The compound silver sulfide has the formula Ag₂S. Which of the following best describes the meaning of the subscript 2 in the formula?

The silver ion has a charge of -2.

The silver ion has a charge of +2.

There are two silver ions for every one sulfide ion.

There are two sulfide ions for every one silver ion.

C. Because the 2 comes after the symbol for silver (Ag), it shows how many silver atoms are in one particle of the compound. See Lesson: Chemical Bonds.

Explanation

C. Because the 2 comes after the symbol for silver (Ag), it shows how many silver atoms are in one particle of the compound. See Lesson: Chemical Bonds.

18. A roller-coaster car reaches a circular portion of the track at a speed of 16.0 meters per second. If the circle has a radius of 22.5 meters and the car maintains its speed all the way around, what is its acceleration toward the center of the circle?

0.71 m/s2

11.4 m/s2

19.0 m/s2

256 m/s2

Explanation

19. Which is a characteristic of water?

Nonpolarity

Low boiling point

Organic in nature

Universal solvency

D. Water is an excellent solvent that has the ability to dissolve many different substances and participate in a wide range of biochemical reactions. See Lesson: An Introduction to Biology.

Explanation

D. Water is an excellent solvent that has the ability to dissolve many different substances and participate in a wide range of biochemical reactions. See Lesson: An Introduction to Biology.

20. A car at a certain point on a circular racetrack experiences centripetal acceleration to the west. What is the direction of the centripetal acceleration when the car goes halfway around the circle from that point?

East

North

South

West

A. Draw a circle and mark the rightmost point as the location of the car. If north is up, then the centripetal acceleration of the car will be west—that is, to the left. Next, mark the leftmost point on the circle: this is the location of the car after it has gone halfway around the circle. Because the centripetal acceleration is always toward the center of circular motion, it will be east—that is, to the right. See Lesson: Friction.

Explanation

A. Draw a circle and mark the rightmost point as the location of the car. If north is up, then the centripetal acceleration of the car will be west—that is, to the left. Next, mark the leftmost point on the circle: this is the location of the car after it has gone halfway around the circle. Because the centripetal acceleration is always toward the center of circular motion, it will be east—that is, to the right. See Lesson: Friction.

21. An electron has a mass of 9.11 m 10^-31 kg. When this value is represented in standard notation, how many zeros are between the decimal point and the nearest non-zero digit?

29

30

31

32

B. Because the exponent is negative, the decimal point moves to the left to convert to standard notation. After moving one space, it is on the other side of the 9. It moves 30 more spaces to the left, and the spaces are filled with zeros. See Lesson: Scientific Notation.

Explanation

B. Because the exponent is negative, the decimal point moves to the left to convert to standard notation. After moving one space, it is on the other side of the 9. It moves 30 more spaces to the left, and the spaces are filled with zeros. See Lesson: Scientific Notation.

22. Which gives the correct order of cellular respiration?

Glycolysis, Acetyl coA, Citric Acid Cycle, Electron Transport Chain

Citric Acid Cycle, Glycolysis, Acetyl coA, Electron Transport Chain

Glycolysis, Acetyl coA, Electron Transport Chain, Citric Acid Cycle

Glycolysis, Citric Acid Cycle, Electron Transport Chain, Acetyl coA

A. A cell produces energy through metabolism by breaking glucose molecules into pyruvate. This happens via glycolysis. The pyruvate molecule is prepped for the citric acid cycle by being oxidized to acetyl coA. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

Explanation

A. A cell produces energy through metabolism by breaking glucose molecules into pyruvate. This happens via glycolysis. The pyruvate molecule is prepped for the citric acid cycle by being oxidized to acetyl coA. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

23. Which of the following statements is true regarding bond that forms between two oxygen atoms in a molecule of O₂?

The oxygen atoms share electrons equally.

One oxygen atom pulls harder on shared electrons than the other.

One atom of oxygen loses two electrons, while the other gains two electrons.

There is not enough information to describe the bond in a molecule of oxygen

A. The bond holds two atoms of the same element together, which means there is no electronegativity difference and electrons are shared equally. The oxygen atoms have the same pull on shared electrons. See Lesson: Chemical Bonds.

Explanation

A. The bond holds two atoms of the same element together, which means there is no electronegativity difference and electrons are shared equally. The oxygen atoms have the same pull on shared electrons. See Lesson: Chemical Bonds.

24. What is the maximum amount of KClO3 that can be dissolved in 50 grams of water at 30°C?

5 grams

10 grams

20 grams

70 grams

A. The graph shows that at 30°C, 10 grams of KClO3 can dissolve in 100 grams of water. Half that amount of water (50 grams) will be able to dissolve half the amount of KClO3 (5 grams). See Lesson: Chemical Solutions.

Explanation

A. The graph shows that at 30°C, 10 grams of KClO3 can dissolve in 100 grams of water. Half that amount of water (50 grams) will be able to dissolve half the amount of KClO3 (5 grams). See Lesson: Chemical Solutions.

25. A 100-watt light bulb runs off a 120-volt source. If 0.83 amps flow through the bulb, what is its resistance?

100 ohms

120 ohms

140 ohms

270 ohms

C. Use Ohm’s law:
V=IR
R=V/I=(120 volts)/(0.83 amps)=140 ohms
See Lesson: Electricity and Magnetism.

Explanation

C. Use Ohm’s law:
V=IR
R=V/I=(120 volts)/(0.83 amps)=140 ohms
See Lesson: Electricity and Magnetism.

26. Given the cooling curve below, what is the melting point of titanium?

500°C

1500°C

1700°C

3300°C

C. In the cooling curve, the melting point is where the second plateau in temperature occurs, which is around 1700°C. See Lesson: States of Matter.

Explanation

C. In the cooling curve, the melting point is where the second plateau in temperature occurs, which is around 1700°C. See Lesson: States of Matter.

27. An object simultaneously experiences forces of (3.1, 5.4), (–2.6, 1.9), and (0, –4.3) in newtons. What is the net force on the object?

(0, –44) N

(0.50, 3.0) N

(0.71, 1.7) N

(5.7, 12.0) N

B. The net force is the sum of all forces acting on the object. To calculate net force, add the corresponding elements of the vectors:

(3.1, 5.4) + (–2.6, 1.9) + (0, –4.3) = (0.50, 3.0)

See Lesson: Nature of Motion.

Explanation

B. The net force is the sum of all forces acting on the object. To calculate net force, add the corresponding elements of the vectors:

(3.1, 5.4) + (–2.6, 1.9) + (0, –4.3) = (0.50, 3.0)

See Lesson: Nature of Motion.

28. Which process is anabolic?

Glycolysis

Lipid synthesis

Protein degradation

Oxidative phosphorylation

B. Lipid synthesis is anabolic because monomers like fatty acids are used to synthesize lipid molecules. See Lesson: An Introduction to Biology.

Explanation

B. Lipid synthesis is anabolic because monomers like fatty acids are used to synthesize lipid molecules. See Lesson: An Introduction to Biology.

29. NaOH is a Lewis base because it

Creates hydroxide ions in water.

Donates a lone pair of electrons.

Accepts hydrogen ions from acids.

Completely dissociates in solution.

B. Lewis bases donate an electron pair in a reaction. This is the case for NaOH, which donates a lone pair of electrons from its hydroxide ion to other compounds. See Lesson: Acids and Bases. .

Explanation

B. Lewis bases donate an electron pair in a reaction. This is the case for NaOH, which donates a lone pair of electrons from its hydroxide ion to other compounds. See Lesson: Acids and Bases. .

30. Which ions from a base react with hydrogen ions in a neutralization reaction?

CH3+

OH-

H3O+

COOH-

B. When hydroxide ions (OH^-) from a base react with hydrogen ions from an acid, both water and salt are formed. See Lesson: Acids and Bases.

Explanation

B. When hydroxide ions (OH^-) from a base react with hydrogen ions from an acid, both water and salt are formed. See Lesson: Acids and Bases.

31. What voltage is necessary to deliver 0.40 amps to a 2.5 m 10³-ohm resistor?

1.6 × 10–4 volts

1.0 × 103 volts

2.9 × 103 volts

6.3 × 103 volts

B. Use Ohm’s law:

V=IR

V = 0.40 amps × (2.5×10³ ohms) = 1.0×10³ volts

See Lesson: Electricity and Magnetism.

Explanation

B. Use Ohm’s law:

V=IR

V = 0.40 amps × (2.5×10³ ohms) = 1.0×10³ volts

See Lesson: Electricity and Magnetism.

32. Zinc-64 is one possible isotope of the element zinc. Which of the atoms described below is a different isotope of zinc?

34 protons, 34 neutrons, 34 electrons

34 protons, 30 neutrons, 34 electrons

30 protons, 36 neutrons, 30 electrons

64 protons, 34 neutrons, 34 electrons

C. Zinc-64 contains 30 protons and 34 neutrons. An isotope would contain the same number of protons but a different number of neutrons. See Lesson: Scientific Notation.

Explanation

C. Zinc-64 contains 30 protons and 34 neutrons. An isotope would contain the same number of protons but a different number of neutrons. See Lesson: Scientific Notation.

33. A patient has a fever of 105°C. What is this value in Fahrenheit?

137

157

189

221

D. Use the following equation to convert Celsuis to Fahrenheit: F = (9/5)C + 32 Where F = (9/5) × 105°C + 32 = 221. See Lesson: Temperature and the Metric System.

Explanation

D. Use the following equation to convert Celsuis to Fahrenheit: F = (9/5)C + 32 Where F = (9/5) × 105°C + 32 = 221. See Lesson: Temperature and the Metric System.

34. Inside a plant, water has to travel up, against gravity, to reach all the leaves. What property does this illustrate?

Adhesion

Bonding

Cohesion

Polarity

C. As the water molecules are attracted to each other, which is cohesion, they also adhere to the sides of the xylem vessels, which transport water up to where it is needed in the plant. See Lesson: Properties of Matter.

Explanation

C. As the water molecules are attracted to each other, which is cohesion, they also adhere to the sides of the xylem vessels, which transport water up to where it is needed in the plant. See Lesson: Properties of Matter.

35. Successive troughs of a sound wave arrive through a certain liquid every 0.040 seconds. If they are 100 feet apart, how fast are they traveling?

0.00040 feet per second

4.0 feet per second

25 feet per second

2,500 feet per secon

D. The period is the time between the arrival of successive peaks or troughs of a wave. The frequency is the reciprocal of the period: in this case, 25 Hz. Use the wave-speed formula:
v=λf
v=(25 Hz)×(100 feet)=2,500 feet per second
See Lesson: Waves and Sounds.

Explanation

D. The period is the time between the arrival of successive peaks or troughs of a wave. The frequency is the reciprocal of the period: in this case, 25 Hz. Use the wave-speed formula:
v=λf
v=(25 Hz)×(100 feet)=2,500 feet per second
See Lesson: Waves and Sounds.

36. What is the height above ground of a 55 g egg that possesses 0.27 J of potential energy?

0.00050 m

0.0050 m

0.050 m

0.50 m

Explanation

37. Which of the following elements will form a polar covalent bond with phosphorus?

Argon

Calcium

Oxygen

Silver

C. All covalent bonds, including polar covalent bonds, are formed between two nonmetals or metalloids. Oxygen and argon are both nonmetals, but argon is a noble gas and will not form a bond because of its stability. See Lesson: Chemical Bonds.

Explanation

C. All covalent bonds, including polar covalent bonds, are formed between two nonmetals or metalloids. Oxygen and argon are both nonmetals, but argon is a noble gas and will not form a bond because of its stability. See Lesson: Chemical Bonds.

38. Adenine and guanine belong to a class of organic molecules called _____.

Enzymes

Nucleotides

Purines

Pyrimidines

C. Adenine and guanine belong to a class of organic molecules called purines, which are large molecules. See Lesson: Genetics and DNA.

Explanation

C. Adenine and guanine belong to a class of organic molecules called purines, which are large molecules. See Lesson: Genetics and DNA.

39. In eukaryotes, what does transcription produce?

MRNA

Pre-mRNA

RRNA

TRNA

B. In eukaryotes, transcription produces pre-mRNA. See Lesson: Genetics and DNA.

Explanation

B. In eukaryotes, transcription produces pre-mRNA. See Lesson: Genetics and DNA.

40. If sodium sulfide (Na₂S) and hydrochloric acid (HCl) react in a double-replacement reaction, what product(s) form?

Na2SHCl

NaHCl + S

NaCl + H2S

HCl + Na2S

C. In a double-replacement reaction, two components, one from each reactant, change places. In this case, sodium and hydrogen replace each other. See Lesson: Chemical Solutions.

Explanation

C. In a double-replacement reaction, two components, one from each reactant, change places. In this case, sodium and hydrogen replace each other. See Lesson: Chemical Solutions.

ACT Science Exam 4

1. A child falls down and punctures his skin. What biological process must occur to repair the damaged skin?

2.

What first name or nickname would you like us to use?

2. In which state of matter are the intermolecular forces between particles in a substance the strongest?

5. The amount of heat that has been removed from the substance allows the particles to draw closer together, and the material changes from a liquid to a solid. Which of the following is being described?

6. What is the name for Earth's outermost layer?

7.

8. Which organelle is DNA found in?

9. What are giant stars?

10. A student notices a pattern of stripes on five tigers. Each of the five tigers has the same stripe pattern. Using his inductive reasoning, what does he logically assume based on this information?

11. How many meters are equivalent to 45.5 kilometers?

12. What organelle plays a role in assembling subunits for protein synthesis?

13. What is the correct order of phases in mitosis?

14. What is the function of a centromere?

15. Which of the following are the three main phases of the water cycle on Earth?

16. What is the momentum of a golf ball with a mass of 45.9 g moving at 81 m/s in ?

17. The compound silver sulfide has the formula Ag2S. Which of the following best describes the meaning of the subscript 2 in the formula?

18. A roller-coaster car reaches a circular portion of the track at a speed of 16.0 meters per second. If the circle has a radius of 22.5 meters and the car maintains its speed all the way around, what is its acceleration toward the center of the circle?

19. Which is a characteristic of water?

20. A car at a certain point on a circular racetrack experiences centripetal acceleration to the west. What is the direction of the centripetal acceleration when the car goes halfway around the circle from that point?

21. An electron has a mass of 9.11 m 10-31 kg. When this value is represented in standard notation, how many zeros are between the decimal point and the nearest non-zero digit?

22. Which gives the correct order of cellular respiration?

23. Which of the following statements is true regarding bond that forms between two oxygen atoms in a molecule of O2?

24. What is the maximum amount of KClO3 that can be dissolved in 50 grams of water at 30°C?

25. A 100-watt light bulb runs off a 120-volt source. If 0.83 amps flow through the bulb, what is its resistance?

26. Given the cooling curve below, what is the melting point of titanium?

27. An object simultaneously experiences forces of (3.1, 5.4), (–2.6, 1.9), and (0, –4.3) in newtons. What is the net force on the object?

28. Which process is anabolic?

29. NaOH is a Lewis base because it

30. Which ions from a base react with hydrogen ions in a neutralization reaction?

31. What voltage is necessary to deliver 0.40 amps to a 2.5 m 103-ohm resistor?

32. Zinc-64 is one possible isotope of the element zinc. Which of the atoms described below is a different isotope of zinc?

33. A patient has a fever of 105°C. What is this value in Fahrenheit?

34. Inside a plant, water has to travel up, against gravity, to reach all the leaves. What property does this illustrate?

35. Successive troughs of a sound wave arrive through a certain liquid every 0.040 seconds. If they are 100 feet apart, how fast are they traveling?

36. What is the height above ground of a 55 g egg that possesses 0.27 J of potential energy?

37. Which of the following elements will form a polar covalent bond with phosphorus?

38. Adenine and guanine belong to a class of organic molecules called _____.

39. In eukaryotes, what does transcription produce?

40. If sodium sulfide (Na2S) and hydrochloric acid (HCl) react in a double-replacement reaction, what product(s) form?

17. The compound silver sulfide has the formula Ag₂S. Which of the following best describes the meaning of the subscript 2 in the formula?

21. An electron has a mass of 9.11 m 10^-31 kg. When this value is represented in standard notation, how many zeros are between the decimal point and the nearest non-zero digit?

23. Which of the following statements is true regarding bond that forms between two oxygen atoms in a molecule of O₂?

31. What voltage is necessary to deliver 0.40 amps to a 2.5 m 10³-ohm resistor?

40. If sodium sulfide (Na₂S) and hydrochloric acid (HCl) react in a double-replacement reaction, what product(s) form?