Massachusetts Comprehensive Assessment System Science Grade 8

1.A neutral carbon atom has 6 protons. Which statement identifies this atom?

2.A bus in Worcester starts moving forward. A standing passenger seems to lurch backward relative to the bus. Why does that happen?

3.A cranberry vine in Carver makes food in its leaves on a sunny day. Which word equation best describes photosynthesis?

4.Walden Pond in Concord sits in sand and gravel left by the last glacier. Geologists call it a kettle pond. How does a kettle pond form?

5.In a class model of trout in the Deerfield River, the fish are already born with different spotting. Herons catch the easiest fish to see. After many generations, harder-to-see spotting is more common. Which statement explains the change?

6.Students in Pittsfield put baking soda and vinegar in a bottle, seal it, and set it on a balance. A gas forms inside. What happens to the total mass?

7.A cell from a maple leaf in the Berkshires and a cell from a rabbit muscle both release usable energy from food. Which structure is the main site of that release in both cells?

8.On a hot afternoon at Crane Beach in Ipswich, the sand is much warmer than the ocean, and wind blows from the water onto the beach. What causes this sea breeze?

9.A cart in a Lowell classroom has a mass of 4 kilograms. A net force of 8 newtons pushes it forward. What is the cart's acceleration?

10.On the periodic table, helium and neon are in the same column. What do elements in the same column generally share?

11.A human body cell has 46 chromosomes. How many chromosomes are in one human egg cell, and what does fertilization do?

12.In January, ice covers Spy Pond in Arlington while liquid water remains below the ice. Why does the ice stay on the surface?

13.A salt-marsh food chain is written as algae to small fish to heron. What do the arrows show?

14.A steel bicycle left in salty air near Salem develops a reddish brown coating. What kind of change is rusting?

15.A whale-watch boat leaves Gloucester and travels 24 kilometers in 2 hours at a steady pace. What is its average speed?

16.At noon on Boston Common, a flagpole's shadow is shorter in June than in December. Why?

17.In a pea-plant model, T stands for tall and is dominant, and t stands for short. Two heterozygous plants, Tt and Tt, are crossed. What fraction of the offspring are expected to be short?

18.A metal spoon sits in hot cocoa in a kitchen in Amherst. The handle becomes hot even though it never touches the cocoa. How does thermal energy reach the handle?

19.Several Boston Harbor islands are smooth oval hills of glacial sediment, now partly surrounded by the sea. What are hills of that shape called?

20.A student says a gene, a chromosome, and DNA are three names for the same object. Which comparison is accurate?

21.A swimmer in Gloucester trains all summer and develops stronger shoulder muscles. Which statement about the swimmer's future child is accurate?

22.Students in Plymouth ask why a lunar eclipse does not happen at every full Moon. Which explanation is correct?

23.A sample of Quincy granite has a mass of 54 grams and a volume of 20 cubic centimeters. What is its density, and will it sink in fresh water?

24.Students compare bean growth under two light levels. Each group has ten similar plants in matching pots with equal soil and water. Why use several plants per group?

25.A student thinks Earth's atmosphere is mostly oxygen because people breathe oxygen. Which statement is correct?

26.On a January morning in Greenfield, ice crystals form on a window although no rain fell. Water vapor from the room's air became ice. What is that change of state called?

27.A humpback whale feeding at Stellwagen Bank has a flipper with one upper-arm bone, two forearm bones, and smaller bones toward the tip, the same pattern as a human arm. What does that similarity suggest?

28.A barge moves in a straight line through the Cape Cod Canal at constant velocity. Its engine pushes forward, and water resistance pushes backward with equal strength. What is the net force on the barge?

29.A herring caught off Cape Ann contains proteins, fats, and sugars. Which element is part of all of these molecules of living things?

30.A cloud forms over the Pioneer Valley. A student says the visible cloud is water vapor. What is the cloud actually made of?

31.Two equal-area marsh plots contain 12 and 20 seedlings. A student doubles both dimensions of the first plot and then compares its raw count with the second. Why is the comparison weakened?

32.A cell from a red oak in the Blue Hills has a flexible boundary that lets some materials through and blocks others. What is that boundary?

33.In Massachusetts, the Sun appears to rise in the east and set in the west about once each day. What motion of Earth causes that daily pattern?

34.Fallen leaves pile up on the forest floor at Mount Greylock. Fungi and bacteria feed on the dead leaves. What is their role in the ecosystem?

35.A model lighthouse in Hull uses two bulbs in one series circuit. One bulb breaks, and the second bulb goes out too. Why?

36.Four water samples are tested in a Newburyport classroom. Which sample is acidic?

37.Early in January, Earth reaches its closest point to the Sun. A town in Massachusetts is still in winter that month. What does that fact show?

38.Two pea plants are both tall. One has genotype TT, and the other has genotype Tt. Tall is dominant. What is true of these two plants?

39.Sand at Crane Beach grows hot in sunlight even though empty space lies between the Sun and Earth. How does that energy cross the space?

40.Sedimentary rock in Holyoke preserves dinosaur footprints. No dinosaur bones are in that same set of prints. What can the footprints still show?

41.In a wave tank in Cambridge, a water wave has a frequency of 4 hertz and a wavelength of 0.5 meter. What is the wave speed?

42.In a Berkshire forest, fungi on tree roots help the roots take in water and minerals. The tree shares sugars with the fungi. What relationship is this?

43.A diagram shows one bacterial cell dividing into two cells. What is the name of this type of reproduction?

44.A cold front crosses Massachusetts. Cold air moves into a region of warmer air. What usually happens along that boundary?

45.Carbon-12 and carbon-14 are both carbon. What is different about the atoms of these two isotopes?

46.A current along the outer Cape picks up sand and later drops that sand where the water slows. What are those two processes, in order?

47.A student plucks two strings in a Northampton music room. The second sound has a higher pitch. Which wave property is greater for that higher pitch?

48.Which list places levels of organization in order from smallest to largest?

49.Many Cape Cod towns pump drinking water from underground. Sandy glacial deposits let rain soak downward. Where is that underground water held?

50.A class uses kinetic energy = 1/2 times mass times speed squared. A 2-kilogram model boat in a Gloucester tank moves at 3 meters per second. What is its kinetic energy?

51.A road cut in the Pioneer Valley shows flat sedimentary layers that have not been overturned. Where are the oldest layers?

52.A student riding a bike in Northampton squeezes the brakes and slows down. The wheel rims feel warm. Why do the rims warm up?

53.Near the Concord River, a dominant allele for red petals is rare, while a recessive allele for white petals is common. Which statement uses dominant correctly?

54.A pencil standing in a glass of water at a Salem school looks bent at the waterline. What causes that appearance?

55.A model predicts 2 centimeters of plate motion per year. After 15 years a marker has moved 31 centimeters. Which statement best compares model and observation?

56.A mouse in a field near Amherst and the grass beneath it both carry out cellular respiration. What does that process do?

57.A student in Salem brings the north pole of one bar magnet near the north pole of a second magnet. What happens?

58.A pond receives fertilizer runoff. Algae increase, then die; dissolved oxygen falls afterward. Which follow-up measurement best tests the proposed role of decomposers?

59.Over about a month in Plymouth, the Moon changes from a thin crescent to full and then toward a crescent again. What are these monthly phases?

60.A rock sample has a mass of 2 kilograms in Boston. Astronauts take that same rock to the Moon. Which statement is correct?

61.Granite from Cape Ann has large interlocking crystals. It formed when magma cooled slowly underground. What type of rock is it?

62.A class model says about 10 percent of the energy at one feeding level is stored in the next level. Salt-marsh producers store 8,000 energy units. About how many units do the primary consumers store?

63.A DNA change occurs in a person’s skin cell. Another occurs in an egg cell that is later fertilized. Which could enter the child’s inherited DNA?

64.The water level at a Gloucester dock rises and falls about twice each day. What is the main cause of those tides?

65.Near the Quabbin Reservoir, a student burns a small dry stick of wood in a fire ring and folds a paper trail map. Which comparison is correct?

66.A distance-time graph for a cyclist on the Cape Cod Rail Trail is a horizontal segment from 10 minutes to 20 minutes. What was the cyclist doing during that interval?

67.Carbon dioxide in the atmosphere absorbs infrared energy leaving Earth's surface. Burning fossil fuels in Massachusetts adds carbon dioxide. Which statement best describes the greenhouse effect?

68.A student in Lowell stirs table salt into water until no crystals are visible. Every spoonful of the liquid is equally salty. What kind of mixture is this?

69.A rower on the Charles River pushes water backward with an oar, and the boat moves forward. Which statement names the third-law force pair?

70.Marble in the Berkshires formed when limestone was buried and changed by heat and pressure. The limestone did not melt. What type of rock is the marble?

71.Young herring in Massachusetts Bay are not identical to either parent. Which statement best explains the genetic variation from this sexual reproduction?

72.In a tall chamber with the air removed at a Boston science museum, a steel bolt and a cork are released together. There is no air resistance. What happens?

73.Water evaporates from Buzzards Bay, clouds form, and rain later falls on the Berkshires. Some of that rain flows into the Housatonic River. Which processes are these?

74.A cranberry-leaf cell and a deer cell both keep their DNA inside a membrane-bound structure. What is that structure?

75.After a balloon is rubbed on dry hair in a Worcester classroom, the balloon and the hair attract each other. Why?

76.At solar noon in June, a student in Worcester looks at the shadow of a vertical stick. Massachusetts is north of the Tropic of Cancer. Which way does the shadow point?

77.A class records 2, 5, 8, and 5 degrees Celsius on four mornings. Which conclusion is supported?

78.A student calls the far side of the Moon the dark side and says sunlight never reaches it. What is wrong with that claim?

79.A sealed car tire in Fitchburg is filled on a warm afternoon. The next morning is much colder, and the tire's volume stays about the same. What happens to the air pressure inside?

80.White-tailed deer live in woods near Worcester. Food and winter shelter can support only a limited number of deer year after year. What is that long-term limit called?

81.Boston is at about 42 degrees north latitude. About how high above the northern horizon does Polaris appear there?

82.A bucket from Duxbury beach holds sand mixed with salty seawater. The sand settles, and the water stays salty. Which statement about this mixture is correct?

83.Water held high behind a dam on the Deerfield River flows down through a generator. Which energy description best fits that system?

84.Herring gulls and great black-backed gulls nest on the same Boston Harbor island, and good nesting space is limited. What interaction is this?

85.A star chart says a certain star is many light-years from Massachusetts. What does a light-year measure?

86.In winter at Halibut Point in Rockport, water seeps into a crack in granite and freezes. The crack grows a little wider. Why can the freezing water push the rock apart?

87.A bell rings inside a glass jar in a Springfield classroom. A pump removes the air. The sound fades until it cannot be heard, but the bell remains visible. What does this show?

88.During a solar eclipse, the Moon's shadow falls on part of Earth. At which Moon phase can a solar eclipse occur?

89.A student runs beside the Charles River. Leg muscles need more oxygen, breathing speeds up, and the heart pumps faster. Which two body systems work together to deliver that oxygen?

90.Two sound waves travel through the air in a quiet room in Concord. They have the same frequency, but one has a larger amplitude. How does the larger-amplitude sound compare?

91.The 1755 Cape Ann earthquake damaged buildings in Boston, even though Massachusetts is not on a plate boundary. What does that event show?

92.A maple leaf in Concord looks green in sunlight before its autumn color change. Why does the healthy leaf look green?

93.Earth keeps circling the Sun instead of flying off in a straight line. Which pair of ideas explains the orbit?

94.A log burns in an open fireplace in Lenox. The remaining ash has much less mass than the log had. Was mass destroyed?

95.A class models seismic-wave travel at a constant 5 kilometers per second. A station 100 kilometers away records an arrival after 20 seconds. What does this observation show?

96.In January, the ocean off Cape Ann changes temperature more slowly than the land around Worcester. Which property of water best helps explain the ocean's slower change?

97.Students compare an ice cube, liquid water, and water vapor that all came from the same sample in a Brookline classroom. Which statement about the particles is correct?

98.Earth's average distance from the Sun is about 150 million kilometers, and light travels about 300,000 kilometers each second. About how long does sunlight take to reach Massachusetts?

99.Two matching coolers each hold equal ice blocks. One has foam lining and one has no lining. After an hour in the same room, more ice remains in the lined cooler. What is supported?

100.Piping plovers nest on sandy Massachusetts beaches. Their speckled, sand-colored eggs are hard for predators to see. What name fits a heritable trait that helps survival in that environment?

101.Two students each move at 4 meters per second. One walks east along the Esplanade in Boston, and the other walks west. Which comparison is correct?

102.In a class model, a grain of Cape Cod sand is buried and cemented into sandstone. Later that sandstone melts, and the melt cools into a new rock. What does the model show?

103.Genetically identical plants grow under two light levels with other conditions matched. Leaf sizes differ between groups. Which conclusion is best supported?

104.A circuit in a Brockton classroom uses copper wire covered with rubber. Why are these two materials used together?

105.Much of the rain that falls in Newton drains to the Charles River and then to Boston Harbor. What is the Charles River watershed?

106.A 3-kilogram bag is lifted 2 meters. Use g = 10 newtons per kilogram. If the height doubles with the same bag, how does the gain in gravitational potential energy change?

107.A blizzard hits Boston on one January day. A student says that single storm is the climate of Massachusetts. Which description is better?

108.Vinegar bubbles when it is poured on a piece of chalk in a Fall River classroom, and a gas forms. Which statement about the atoms is correct?