UPCAT Review - General Science Review 1 PDF

REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 1|Page  UPCAT Review – Science Review 1 Downloadable e-Book TM...

REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 1|Page  UPCAT Review – Science Review 1 Downloadable e-Book TM Copyright © 2011 Review Masters. REVIEW MASTERS, upcatreview.com, Online UPCAT Review and other related indicia are trademarks of KB Tutorial and Consulting Corp. All rights reserved worldwide This book cannot be redistributed without permission from KB Tutorial and Consulting Corp. More info at: http://www.upcatreview.com For INFO and UPDATES, check out upcatreview.com, the official website of Review Masters and the Online UPCAT Review® Keep updated about UPCAT materials, reviewers, tips and news TM Copyright © 2011 Review Masters - http://www.upcatreview.com  PREFACE Believe That You Can Pass the UPCAT! by Leopold Laset Do you sometimes find it hard to believe that your dream to pass the UPCAT can become a reality? If so, then there is something very important that you need to know. UPCAT is for dreamers like you. Every student who passed the UPCAT began thinking or dreaming of passing the UPCAT. Your near-perfect or perfect score in a quarterly test, your cellphone, PSP, or any gadget, your out-of-town (or out-of- country) vacation, your new pair of shoes, and any other stuff that you desired and now possess - are all the result of your ‘dream come true’. What this means is that throughout your lifetime, you have had an idea, you have desired for many things and worked hard for them, overcome problems and ultimately transformed your dream into reality. And if hundreds and thousands of students have been able to pass the UPCAT in the past, by starting with a dream, then it stands to reason, that you can do it too. Often we make the mistake of thinking that UPCAT is for a small number of bright students who have the brains and intelligence that we don’t possess. But this is simply not true. The fact that thousands of average students have brought their dreams of passing the UPCAT to fruition in the past demonstrates that the opportunity to qualify in the UPCAT is something that is available to each UPCAT aspirant – average or bright. Right now, hundreds of UPCAT dreamers are taking the steps necessary to achieve the goals of passing the UPCAT. Some are studying this early, some are joining community of fellow dreamers, and some are attending review classes. What is it that you need to do? In order to achieve your goal of passing the UPCAT, the only things you really need are: (1) A crystal clear picture that you already passed the UPCAT (2) An unshakeable determination to do whatever it takes to make your dream of passing the UPCAT a reality As soon as you take these two steps, passing the UPCAT becomes achievable. If you need a help – you look for it. If you encounter a difficult concept – you find a way to understand it. If you can’t solve a math problem – you try and try and practice more. And gradually, step-by-step, you bring your UPCAT dream into reality to join the dreams of the thousands of UPCAT dreamers who have gone before you. So today I’d like to encourage you to believe in yourself and appreciate the fact that you live in a world where ‘dreams do come true’. Understand that thousands of students have made their UPCAT dream a reality in the past – Thousands more will make their UPCAT dream a reality in the near future and you CAN be one of them. REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com GENERAL SCIENCE CONTENTS  Structure of the Earth  Theory of Continental Drift  Seafloor Spreading  Theory of Plate Tectonics  Plate Boundaries  Earthquakes  Volcanoes  Minerals  Rocks  Weathering and Erosion  Change and Earth’s History  The Atmosphere TABLE OF CONTENTS page REVIEW TEST --------------------- 4 ANSWERS AND EXPLANATIONS --------------------- 15 2|Page REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com ANSWER SHEET – GENERAL SCIENCE PLEASE DETACH ALONG PERFORATION Correct Filling A B C D A B C D A B C D A B C D A B C D Incorrect Filling A B C D A B C D A B C D Please use No. 2 Pencil A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D 3|Page REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com GENERAL SCIENCE REVIEW TEST For questions 1-3 please refer to the following choices: A. Gold and silver B. Iron and nickel C. Oxygen and silicon 1. What materials are abundant in the crust? 2. What does the mantle contain? 3. The metals _______ make up most of the earth’s core. 4. Which does not belong to the group? A. asthenosphere B. mesosphere C. lithosphere D. troposphere 5. Movement of tectonic plates is due to the hot, flowing condition of the asthenosphere. What is the term for semi-liquid condition? A. fluidity B. malleability C. plasticity D. rigidity 6. The outer core is ________ because _________ is the controlling factor. A. solid – temperature C. liquid – temperature B. liquid – pressure D. solid – pressure 7. The inner core is ______ because _______ is the controlling factor. A. solid – temperature C. liquid – temperature B. liquid – pressure D. solid – pressure 8. Energy in the mesosphere moves slowly by ________. A. conduction B. convection C. radiation D. conduction and radiation 9. The crust is made up of two separate layers: the oceanic crust and the continental crust. Which of the following characterizes the oceanic crust? A. exhibits folded mountain formation C. composed of granite and rhyolite B. composed of basalt and gabbro D. composed of rocks with low density 10. Which make up continental crust? A. basalt and gabbro C. limestone and sandstone B. granite and rhyolite D. granite and basalt 11. Which make up the lithosphere? A. crust C. upper mantle B. crust and upper mantle D. upper and lower mantle 4|Page REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 12. The shadow zone is the boundary between the _______? A. crust and upper mantle C. lower mantle and outer core B. upper mantle and lower mantle D. outer core and inner core 13. Which best describes primary waves? A. compress and expand particles that lie in their path B. resemble the wavelike motion that results when a rope is stretched from side to side C. both A and B D. none of the above 14. Which illustrates a surface wave? A. compress and expand particles that lie in their path B. resemble the wavelike motion that results when a rope is stretched from side to side C. both A and B D. none of the above 15. Where do the seismic waves from an earthquake go? Seismic waves spread out in A. a straight line C. all directions B. a perpendicular pattern D. no particular direction 16. Why can earthquakes be not detected at the shadow zone? A. It is too deep within the earth. B. The outer core stops P waves and bends S waves. C. The outer core bends P waves and stops S waves. D. The outer core bends L waves. 17. Why are P waves bent as they strike the mantle? A. The core and the mantle have identical properties. B. The core and the mantle have different properties. C. The crust and the mantle have identical properties. D. The crust and the mantle have different properties. 18. A change in direction of a wave as it moves through rock layers of different densities is known as A. deflection B. reflection C. refraction D. diffraction 19. What is the principle of uniformitarianism? A. The geologic processes that occurred in the past are very much different from today’s processes. B. The same processes that shaped the earth are still at work today. C. The laws of nature changes very much over time. D. Only sedimentation occurred. 5|Page REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 20. Which supported the continental drift theory? 1.fossils 2.rock formations 3.continental edges 4.glaciers A. 1 only B. 1 and 2 C. 1, 2, and 3 D. 1, 2, 3, and 4 21. All of the following are associated with seafloor spreading except: A. divergent plate boundaries C. old age of oceanic crust compared to continental crust B. mid-oceanic ridges D. rising of magma from the asthenosphere 22. Which of the following occurs when two oceanic plates collide? A. folded mountain formation C. subduction B. seafloor spreading D. tension 23. Any plate boundary where the plates collide is called a ___________ boundary. A. convergent B. divergent C. strike-slip D. transform 24. The theory of _______ explains all known major surface geological phenomena. A. continental drift C. sea-floor spreading B. plate tectonics D. none of the above 25. What are formed when two continental plates collide? A. folded mountains C. trenches B. rift valleys D. volcanoes 26. Which of the following global locations best shows the action of divergent plate boundaries? A. African rift valley C. Marianas trench B. Himalayan mountain range D. Mayon volcano Questions 27 and 28 are related. 27. The type of stress that can form a trench is _______. A. compression B. friction C. shear D. tension 28. What kind of fault results from # 27? A. gravity B. lateral C. normal D. reverse 29. In a ______ fault, the hanging wall to move upward in relation to the footwall, while in a _____ fault, the hanging wall moves downward in relation to the footwall. A. normal…….reverse C. reverse……thrust B. reverse……normal D. uplift……….thrust 6|Page REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 30. Arrange the following in the correct sequence 1.oceanic crust melts 2.magma rises through the earth’s crust 3.pool of magma forms under the earth’s surface 4.magma solidifies forming a pluton 5.oceanic crust subducts at boundary with continental plate A. 1, 2, 3, 4, 5 B. 5, 4, 3, 2, 1 C. 5, 1, 3, 2, 4 D. 2, 5, 1, 4, 3 31. What kind of fault is formed by tension? A. normal B. reverse C. lateral D. transform 32. On the other hand, what kind of fault is formed by compression? A. normal B. reverse C. lateral D. transform 33. Volcanic eruptions usually occur at the _______ of continents where forces between adjoining tectonic plates are usually the strongest. A. bottom B. edges C. middle D. surface 34. What kind of energy do seismic waves carry? A. kinetic B. light C. potential D. radiant 35. The earth has _______ energy and is changed into ________ energy during an earthquake. A. kinetic…….potential C. mechanical……light B. potential……..kinetic D. light……radiant 36. The energy transformation in # 35 occurs at the ________. A. epicenter B. focus C. Moho D. Shadow zone 37. What happens to the amount of kinetic energy carried by the wave as the wave moves away from the focus? A. decreases B. increases C. remains the same D. fluctuates depending on the substance that the wave passes thru 38. Which earthquake waves are called body waves? A. P and L B. L only C. P and S D. L and S 39. The area along a fault where rocks first break and move is the_______. A. epicenter B. focus C. Moho D. Shadow zone 40. The point on the earth’s surface where an earthquake’s shaking is generally the strongest is________. A. epicenter B. focus C. Moho D. Shadow zone 7|Page REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 41. In volcano, what factor causes magma to move through a pipe? A. heat C. heat and pressure B. pressure D. temperature 42. Which best characterizes a cinder cone volcano? A. has flat top formed from runny lava that flows away from the vent B. has steep sides, generally formed by wet, silica – rich magma C. contain alternating layers of volcanic debris and lava, has steep tops but gently sloping bases D. has steep slopes, contains layers of cinders and lava 43. The _______ seismic waves can cause the most damage because they cause the earth’s surface to move up or down or side to side A. P B. L C. S D. P and S 44. Which best characterizes a mineral? 1.naturally formed 2.solid 3.has definite crystal structure 4.organic 5.maybe an element or a compound A. 1, 2, 3, 4 B. 1, 2, 3, 5 C. 1, 2, 4, 5 D. 1, 3, 4, 5 45. Which is NOT a mineral? A. coal B. diamond C. feldspar D. graphite 46. What is the symbol of quartz? A. Si O2 B. Si2 O2 C. Si2 O D. Si O 47. Ferrous oxides are composed of: A. carbon and oxygen C. iron and oxygen B. ferritin and oxygen D. silicon and oxygen 48. Which is NOT a rock? A. halite B. phyllite C. granite D. marble 49. Which statement is TRUE? A. the color of the mineral is always the same B. the luster of the mineral is always the same C. the streak of the mineral is always the same D. none of the above 50. Specific gravity is the ratio of a mineral’s density to the density of water. What is the specific gravity of a 3 mineral whose density is 5.3 g/cm ? 3 3 A. 5.3 B. 5.3 g/cm C. 5.3 cm /g D. 5.3 g 8|Page REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 51. Moh’s scale is used to determine the ________ of a mineral. A. Hardness B. luster C. malleability D. magnetism 52. A mineral scratches all the other minerals. What is its hardness number in Moh’s scale? A. 9 B. 10 C. 11 D. 12 53. The “lead” in pencil is actually A. charcoal B. graphite C. halite D. quartzite 54. What minerals maybe used to make porcelain? A. borax and feldspar C. talc and halite B. quartz and sulfur D. graphite and gypsum 55. The _________ of a mineral leaves even surface while ______ of a mineral leaves uneven plane. A. fracture…..cleavage C. hardness…..streak B. cleavage….fracture D. specific gravity….streak 56. You have two mineral samples that vary in color but are identical in all other properties. What can you infer about the two samples? A. different mineral, different impurities C. same mineral, different impurities B. different mineral, same impurities D. same mineral, same impurities Questions 57 and 58 are related. 3 57. A sample of a mineral has a mass of 64 g and a volume of 16 cm. What is its density? 3 3 3 3 A. 48 g x cm B. 80 g x cm C. 4 cm /g D. 4 g/cm 58. What is its specific gravity? A. 4 B. 8 C. 16 D. 32 59. Which does NOT belong to the group? A. marble B. sandstone C. schist D. quartzite 60. Which is an igneous rock? A. conglomerate B. gneiss C. obsidian D. phyllite 61. Which is a metamorphic rock? A. schist B. dolomite C. pumice D. limestone 62. Igneous rocks are formed by the _________ of magma. A. cooling and solidifying C. depositing and cementing B. cooling and cementing D. solidifying and depositing 9|Page REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 63. The process by which new rocks are formed thru intense heat and pressure is called ________. A. crystallization B. lithification C. metamorphism D. plastic deformation 64. Both sedimentary rocks are metamorphic foliated rocks have layers. Sedimentary rocks are formed by _________ while foliated rock layers consist of _________. A. particles of different sizes……..different minerals B. particles of the same size……….same minerals C. organisms of different sizes………same minerals D. different minerals…….particles of different sizes 65. When magma cools rapidly, the rocks that form __________. A. have small or no minerals C. have large mineral crystals B. are glassy D. are fractured 66. A rock with two very different textures means that the rock probably A. is sedimentary C. is metamorphic B. formed at two different depths D. formed as two different rocks fused 67. The oldest rock layers lie on the bottom according to the principle of A. crosscutting B. faunal succession C. superposition D. uniform process 68. The parent rock of gneiss is __________. A. clay B. shale C. limestone D. granite 69. Breakdown of rocks due to daily fluctuations in temperature is a form of _________. A. chemical weathering C. mechanical weathering B. leaching D. oxidation 70. Which is NOT a factor of weathering? A. heat C. plants and animals B. temperature and pressure D. magnetic field 71. Frost action breaks rocks apart due to _________. A. the expansion of water as it expands C. the sharp edges of the ice B. the dissolution of minerals by water D. none of the above 72. Which mineral will resist weathering the most? A. calcite B. feldspar C. iron oxide D. quartz 73. The most important product of weathering is _______. A. another rock B. mineral C. soil D. fine particle of rock 10 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 74. Daily temperature changes affect rocks due to the ________ of the outer surface layer of the rock which causes rocks to crack. 1.expansion 2.contraction 3.convection A. 1 only B. 2 only C. 1 and 2 D. 2 and 3 75. Which is not a form of chemical weathering? A. carbonation B. exfoliation C. hydration D. oxidation 76. Why is carbonic acid a significant weathering agent? A. it is a strong acid C. it is common in nature B. it can be artificially synthesized D. it is naturally occurring 77. What forces break / split parent rock into blocks or boulders? 1.mechanical weathering 2.chemical weathering 3.cementation 4.lithification A. 1 only B. 2 only C. 1 and 2 D. 3 and 2 and 4 Classification of rivers depends on how much they erode the areas around them. There are three stages of river erosion: young, mature and old. For questions 78 and 79 refer to the following: A. little erosion at the bottom of the river, steep slope, swift flow, B. presence of rapids and waterfalls V-shaped valleys C. broad, flat floodplain, oxbow lake D. gentle slope, presence of meanders E. rapids and waterfalls, oxbow lake, meanders 78. Which characterizes an old river? 79. Which best describes a young river? 80. Which of the following best explains why nitrogen is the most common gas in the atmosphere? A. it is inert C. it is needed to produce fertilizers B. it is required for respiration D. it is a vital component of amino acids 81. In Northern Hemisphere, air in a cyclone blows ________. A. clockwise C. counterclockwise B. from west to east D. into an area of high pressure 82. The least dense air is found in the ________. A. mesosphere B. stratosphere C. thermosphere D. troposphere 11 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 83. The layer of the atmosphere which contains the ozone gas is ________. A. mesosphere B. stratosphere C. thermosphere D. troposphere 84. In what part of the atmosphere do average sized and large meteors burn in during atmospheric entry? A. exosphere B. ionosphere C. mesosphere D. stratosphere 85. Why don’t we feel pressure of air? A. Pressure inside and outside our bodies are equal. B. Pressure inside our body is greater than the pressure outside our body. C. Pressure inside is lesser than the pressure outside. D. Air pressure is negligible. 86. How are the density of air and the air pressure related to the height above the surface of the earth? A. Density and pressure increases as the height increases. B. Density and pressure decreases as the height increases. C. Density increases with altitude while pressure decreases. D. Density decreases with altitude while pressure increases. 87. Energy that powers weather comes from the sun. How is this energy transferred among the different air masses in the earth? A. convection B. radiation C. conduction D. radiation and conduction 88. The warming of the atmosphere due to the trapping of heat from the sun by carbon dioxide and other gases is known as ________. A. coriolis effect B. ozone depletion C. smog D. greenhouse effect 89. The gas in the stratosphere that absorbs UV radiation is _______. A. oxygen B. neon C. ozone D. carbon 90. The layer of the atmosphere where most airline planes travel in is the _____. A. Stratosphere B. ionosphere C. exosphere D. troposphere 91. The temperature at which air is saturated with water vapor is called the _______. A. saturation point C. freezing point B. evaporation point D. dew point 92. Air mass A is 80% saturated, while air mass B is 60% saturated. Assuming that air temperature is constant, which of the following statements is true? A. Air mass A has lower dew point than air mass B. B. Air mass A has higher dew point than air mass B. C. Air mass A and air mass B have equal dew points. D. No conclusion regarding dew points can be made. 12 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 93. Air mass A has a water vapor amount of 25ppm while air mass B has 50ppm. Assuming air temperature is constant, which of the following statements is true? A. Air mass A would exhibit rain first. B. Air mass B would exhibit rain first. C. Both air masses will exhibit rain at the same time. D. No conclusive statement about rain can be made. 94. Sea and land breezes are caused by _______. 1.uneven heating 2.local changes in air pressure 3.changes in air density A. 1 only B. 2 only C. 1 and 2 D. 1, 2 and 3 95. The _________ corresponds to the solar surface. A. chromosphere B. corona C. photosphere D. radiation zone 96. The _________ is the origin of the solar wind. A. chromosphere B. convection zone C. core D. corona 97. After billions of years, the sun would eventually use up its hydrogen fuel and “die”. It would then become a A. black hole B. red giant C. supernova D. white dwarf 98. new moon  __________  waxing quarter  __________  full moon  __________  waning quarter  __________ new moon A. waxing gibbous  waxing crescent  waning gibbous  waning crescent B. waxing crescent  waxing gibbous  waning crescent  waning gibbous C. waxing gibbous  waxing crescent  waning crescent  waning gibbous D. waxing crescent  waxing gibbous  waning gibbous  waning crescent 99. Which of the following does not belong to the group? A. Jupiter B. Neptune C. Pluto D. Saturn 100. Earth’s axis is tilted at an angle of _______. 0 0 0 0 A. 21.5 B. 23.5 C. 30.2 D. 40.1 13 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com Answers and Explanations 14 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com GENERAL SCIENCE REVIEW TEST – ANSWER KEY 1. Given the abundance of oxygen and silicon in 4. The first three choices belong to the physical the crust, it should not be surprising that the most layers of the Earth. Physical layers are determined abundant minerals in the earth's crust are the by the phase of matter in which they exist. They silicates. are determined by a balance of heat and pressure. Element Approximate There are five physical layers: % by weight 1. The outer most physical layer is the Oxygen 46.6 lithosphere. Physically it is cool and solid. It is Silicon 27.7 made up of the crust and a small part of the Aluminum 8.1 mantle. Iron 5.0 2. Next is the asthenosphere. Physically it is hot and semiliquid. This state is often referred to as Calcium 3.6 having plasticity. It is made of a thin part of the Sodium 2.8 upper mantle. This layer is responsible for Potassium 2.6 movement of plates of the lithosphere which Magnesium 2.1 results from convection currents. All others 1.5 3. The rest of the mantle makes the third layer called the mesosphere. It is hot and solid. 4. The fourth layer is the outer core. Physically it Thus, the answer is C. is hot and liquid. Currents in this layer cause the earth to have a magnetic field. This gives us a magnetic north pole. It is determined by the direction a compass points. We also have a 2. The crust is, in fact, a product of mantle melting. geographic north pole which is determined by So there is also an abundance of oxygen and the axis of rotation of the earth. silicon in the earth’s mantle. 5. The fifth layer is the inner core. Physically it is extremely hot and solid. The pressure is so great Element Approximate at this point that even though it is very hot, the % by weight pressure keeps it solid. Oxygen 44.8 Silicon 21.5 The troposphere is the lowest portion of Earth's Magnesium 22.8 atmosphere. Iron 5.8 Thus, the answer is D. Aluminum 2.2 Calcium 2.3 Sodium 0.3 Potassium 0.03 5. As mentioned in the previous item, physically the asthenosphere is hot and semiliquid. This Thus, the best answer is C. state is often referred to as having plasticity. The plasticity of the asthenosphere is due to its being semi-liquid. Due to the presence of areas with solid rock and areas of magma, the 3. The earth’s core is made up of 90% iron and asthenosphere as a whole flows slowly but 10% nickel. consistently due to convection. Thus, the answer is B. Thus, the answer is C. 15 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 6. Temperature inside the earth increases as depth 11. The lithosphere is composed of the upper increases. These high temperatures are more than crust, 5 km thick in the oceans and 65 km thick enough to melt rock. The outer core, being one on the continents, and the upper mantle, which of the deeper layers of the earth is liquid because makes up the remainder. of the high temperatures present at its location. Thus, the answer is C. 7. The inner core is the innermost layer of the earth. It is therefore located at the hottest part of the earth’s interior. However, it remains solid because of the great pressure exerted by the other earth layers lying above the inner core. The intense pressure compresses the molecules of the inner core and prevents their movement. (movement of molecules is characteristic of liquids and gases) Thus, the answer is D. 8. Energy is transferred between the earth's surface and the atmosphere via conduction, convection, and radiation. Image from http://stloe.most.go.th Conduction is the process by which heat energy Thus, the answer is B. is transmitted through contact with neighboring molecules. Energy in the mesosphere moves slowly by conduction. GENERAL SCIENCE TIP: Convection transmits heat by transporting  Ocean crust is thin, dense and basaltic. groups of molecules from place to place within a  Continental crust is thick, less dense and granitic. substance. Convection occurs in fluids such as water and air, which move freely. 12. The shadow zone is the boundary between the Radiation is the transfer of heat energy without solid lower mantle and the liquid outer core. the involvement of a physical substance in the transmission. Radiation can transmit heat through a vacuum. Thus, the answer is A. 9. The oceanic crust is more dense than continental crust. The oceanic crust is made up of heavier elements (basalt and gabbro). Thus, the answer is B. 10. High percentages of silicon, oxygen and aluminum in the continental crust contribute to a lower density as these elements have small atomic masses. Granite and rhyolite (continental crust) are less dense than basalt and gabbro (oceanic crust). Image from http://www.matter.org.uk Thus, the answer is B. Thus, the answer is C. 16 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 13. The P wave is a longitudinal wave, wherein the 15. As rocks break at the focus, seismic waves are wave vibrates forward and backwards as the it sent out equally in all directions. travels forward. As it passes through rocks, the rock particles go with the motion of the wave; some are stretched (expanded) and some are compressed. Image from http://www.mnh.si.edu Thus, the answer is A. Thus, the answer is C. 14. The motion of surface waves is complex. They compress and expand particles that lie in 16. As mentioned in Item #12, the shadow zone is their path. They resemble ocean waves, only the boundary between the solid lower mantle in rocks. They have side-to-side motion as and the liquid outer core. P waves can pass well that is why they are very damaging to thru both solid and liquid rock. S waves can buildings. ONLY pass thru solid rock. When P waves hit the shadow zone, they bend due to the difference in composition of the mantle and core. When S waves hit the liquid outer core, they stop. The absence of the S wave makes it impossible for seismologists to detect earthquakes at the shadow zone. Thus, the answer is C. 17. Though the P wave can pass through both solid Image from http://www.mnh.si.edu and liquid rock, it will change direction if it passes through the boundary between two earth Thus, the answer is C. layers (core and mantle), if these 2 layers have different properties. GENERAL SCIENCE TIP: Thus, the answer is B.  P waves are faster than S waves. 18. Wave behavior:  P waves passes through liquids,  Reflection (bouncing back of a wave from solids and gases (that’s why people a surface) hear earthquakes) S waves travel  refraction (bending of a wave as it passes through “S” olids only. through a certain substance)  diffraction (a wave is scattered if it passes through a certain substance) Thus, the answer is C. 17 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 19. The processes that shaped the earth in 22. When two plates collide, the denser plate will ancient times (plate tectonics, volcanic move under the other plate. This is subduction. activity, weathering, erosion, etc.) are still The plate that subducts will then sink into the shaping the earth today. mantle and melt. Thus, the answer is B. 20. Continuity of fossil remains and rock formations among separate continents suggest that the present continents were once fused into a single landmass, Pangaea. Image from http://www.platetectonics.com Thus, the answer is C. 23. There are three types of plate boundary, each related to the movement seen along the boundary. Divergent boundaries are where plates move away from each other Image from http:// www.volcano.oregonstate.edu Convergent boundaries are where the Thus, the answer is C. plates move towards each other 21. Sea-floor spreading occurs where oceanic Transform boundaries are where the plates are diverging from one another. This plates slide past each other. lengthening of the crust allows magma from the upper mantle to rise to the surface and cool, commonly forming basalt. As a result, the age of the rocks increases as one moves away from the rift zone. The midoceanic ridge is the primary site for sea-floor spreading. Earthquakes and volcanoes are where sea floor spreading is occurring. Image from http://geology.csupomona.edu Thus, the answer is A. GENERAL SCIENCE TIP:  Mid-oceanic ridge new earth being created sea floor spreading  Trenches earth being destroyed subduction zone Image from http://library.thinkquest.org Thus, the answer is D. 18 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 24. The theory of plate tectonics has done for 26. Divergent plate boundaries are locations where geology what Charles Darwin's theory of plates are moving away from one another. This evolution did for biology. It provides geology occurs above rising convection currents. The with a comprehensive theory that explains rising current pushes up on the bottom of the "how the Earth works." The theory was lithosphere, lifting it and flowing laterally formulated in the 1960s and 1970s as new beneath it. This lateral flow causes the plate information was obtained about the nature of material above to be dragged along in the the ocean floor, Earth's ancient magnetism, the direction of flow. At the crest of the uplift, the distribution of volcanoes and earthquakes, the overlying plate is stretched thin, breaks and flow of heat from Earth's interior, and the pulls apart. worldwide distribution of plant and animal fossils. The East Africa Rift Valley is a classic example of this type of plate boundary. The East Africa Rift is in a very early stage of development. The plate has not been completely rifted and the rift valley is still above sea level but occupied by lakes at several locations. Image from http://pacificislandtravel.com Thus, the answer is B. 25. When two continental plates collide, one plate will be forced only slightly under the other, but no subduction will take place. Thus, the pressing together of two plates will fold the Image from http://blue.utb.edu crust and forms what we known as folded mountains. Thus, the answer is A. 27. Refer to the table below: Type of Fault Type Plate Boundary Stress Type Shear Strike-Slip Transform Tension Normal Divergent Compression Reverse Convergent When two oceanic plates converge, because Thus, the answer is A. they are dense, one runs over the top of the other causing it to sink into the mantle and a GENERAL SCIENCE TIP: subduction zone is formed. The subducting plate is bent down into the mantle to form a  Plate tectonics states deep depression in the seafloor called a trench. the earth’s crust is Trenches are the deepest parts of the ocean and broken into plates which remain largely unexplored. can move. Thus, the answer is A. 19 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 28. Based on the table in #27, the answer is D. 31. There are three basic types of stress, each of which deforms the crust in a different way. The three types of stress are compression, 29. A normal fault occurs when the crust is tension, and shearing. extended. The hanging wall moves downward, relative to the footwall. A reverse fault is the opposite of a normal fault — the hanging wall moves up relative to the footwall. Reverse faults are indicative of shortening of the crust. Image from http://en.wikipedia.org Thus, the answer is B. 30. Images from http://www.cgrove417.org Each of the different forms of stress deforms the crust in a different way. The large arrows show the directions of the forces acting on the rocks. Image from http://www.physicalgeography.net Refer to the table below: Type of Fault Type Plate Boundary The answer is C. Stress Type Shear Strike-Slip Transform GENERAL SCIENCE TIP: Tension Normal Divergent Compression Reverse Convergent What are Seismic Waves ??? The answer is A.  Seismic waves are the vibrations from earthquakes that travel through the Earth. 32. As shown in the table: Type of Fault Type Plate Boundary  They are the waves of energy suddenly created by the Stress Type breaking up of rock within the earth or an explosion. Shear Strike-Slip Transform Tension Normal Divergent  They are the energy that travels through the earth and is recorded on seismographs. Compression Reverse Convergent The answer is B. 20 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 33. The theory of plate tectonics explains that the 36. The focus is the point within the earth’s majority of geological phenomena are interior where rocks first break. This is the concentrated along the edges of plates. It is at staring point of the earthquake and the source the edges or boundaries that plate to plate of the body waves, P and S. interactions occur. Image from http://www1.fccj.cc.fl.us The answer is B. 37. As it travels, kinetic energy decreases until it completely stops. Image from http://upload.wikimedia.org The answer is A. The answer is B. 38. P and S waves are called body waves because 34. The presence of tension, compression or they can travel through the earth’s interior. shear in faults results in a buildup of kinetic energy in the rocks. When rocks break, this potential energy is released as kinetic energy (energy in motion) in the form of seismic waves. Image from http://www.sciencelearn.org.nz Image from http://www.mysciencebox.org The answer is A. The answer is C. 35. See explanation in the previous item. 39. See explanation in item#6. The answer is B. The answer is B. 21 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 40. The epicenter is the point on the earth’s 43. L waves or surface waves are seismic waves surface corresponding to the focus. IT IS NOT originating from the epicenter when the latter THE ORIGIN OF THE EARTHQUAKE. It is reached by body waves traveling from the is also the starting point of the L wave or focus. surface wave. L waves are produced when body waves from the focus hit the epicenter. Image from http://www.sciencelearn.org.nz The answer is B. 44. Choices 1, 2, 3 and 5 are the criteria required Image from http://www.physicalgeography.ne by a substance for it to be called a mineral. The answer is A. The answer is B. 41. Heat ensures that the magma stays liquid, so 45. Coal is the result of the cementation of that it can flow. Pressure forces the magma to fossilized plant parts; therefore it is organic in exit the vent. It moves from an area of high origin. For a material to be classified as a pressure (inside a volcano or vent) to an area mineral it must have an inorganic origin. of low pressure (outside the volcano or on the earth’s surface). The answer is A. The answer is C. 46. Quartz is silicon dioxide (SiO2). 42. Cinder cone volcano is formed when ash and cinder are violently spewed out form an The answer is A. erupting volcano and blown to great heights. This type of volcano is hardly composed of 47. Iron(II) oxide, also known as ferrous oxide, any lava, most cinder and ash. The ash and are chemical compounds composed of iron cinder cone volcano normally have steep sides and oxygen. and a small crater. The answer is C. 48. Halite is a mineral produced by precipitation. The others are rocks, which are composed of several kinds of minerals. The answer is A. 49. The streak refers to the color of the powder line of a mineral. The powder is left on an unglazed white tile when a mineral is rubbed on the tile. The color of this powder is Image from http://library.thinkquest.org constant for a given mineral. The answer is B. The answer is C. 22 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 50. Specific gravity is the ratio of the weight of a 54. Borax and feldspar maybe used to make mineral to the weight of an equal volume of porcelain. water. Ratios do not have units of measurements. The answer is A. The answer is A. 55. Cleavage planes are specific planes or angles of cutting a mineral that result in a smooth 51. The Moh’s scale of hardness has a rating of 1 edge. Minerals have fracture if, when they are – 10, with 1 being the lowest and 10 being the cut, they have uneven surfaces that can either highest. Talc, with a rating of 1, is the softest be jagged, conchoidal, fibrous or irregular. mineral. Diamond has rating of 10. It is the hardest mineral and can scratch all other The answer is B. minerals. 56. Two samples of the same mineral may have different color due to differences in impurities. Impurities are foreign substances that are incorporated in a mineral. The answer is C. 57. The density of a substance is the amount of mass of that substance for every specific unit of its volume. In this example, we divide the mass (64g) by the volume (16cm3) to get 4g/cm3. The answer is D. 58. Specific gravity is the ratio of a mineral’s density to the density of water. min eral ' s density 1 Image from http://www.sodablastingservices.com Specific Gravity =  density of water 4 The answer is A. The answer is A. 52. See the explanation in the previous item. 59. Marble, schist, and quartzite are all metamorphic rocks. Sandstone (sometimes The answer is B. known as arenite) is a sedimentary rock composed mainly of sand-sized minerals or rock grains. 53. Graphite is a mineral composed of a specific crystal arrangement of carbon atoms. Note The answer is B. that different crystal arrangements of the same atom could lead to entirely different minerals GENERAL SCIENCE TIP: with unique characteristics. For example, graphite and diamond are both composed of  Mineral properties depend on internal atomic carbon atoms, yet there properties are entirely arrangement. different. The answer is B. 23 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 60. Obsidian (see figure below) is a dark-colored 64. The stratification in sedimentary rocks is the volcanic glass that forms from the very rapid result of sediments with different sizes cooling of molten rock material. It cools so segregating. A single layer in sedimentary rapidly that crystals do not form. It is an rock is composed of sediments of relatively example of an igneous rock. same size. Another layer would have also have sediments of a particular size. But the Conglomerate is a sedimentary rock sediments between these two layers are composed from the deposition and cementation different. of sediments of different sizes. For foliated metamorphic rocks, the mineral Gneiss rocks are metamorphic. These rocks grains in an individual rock are composed of may have been granite, which is an igneous minerals segregating. A mineral grain would rock, but heat and pressure changed it. be a band composed of the same mineral. Another grain would also have a specific Phyllite is a foliated metamorphic rock mineral. But the minerals between two composed of fine grained sheet silicate separate grains are different. minerals. The answer is A. The answer is C. 65. For atoms to arrange themselves in a crystal 61. Dolomite and limestone are sedimentary structure, they must be able to move. In liquid rocks. Pumice is an igneous rock. magma, this is possible. If magma cools slowly, the atoms spend more time in the Schist rocks are metamorphic. These rocks liquid state; they have more time to move and can be formed from basalt, an igneous rock; arrange themselves in crystals. If magma shale, a sedimentary rock; or slate, a cools rapidly, atoms would be quickly metamorphic rock. Through tremendous heat bound in immovable states (solid); they and pressure, these rocks were transformed can’t rearrange into crystals anymore. into this new kind of rock. The answer is A. The answer is A. 66. Texture would refer to the crystal composition 62. Igneous rocks are crystalline or glassy rocks of igneous rocks. Depending on the depth formed by the cooling and solidification of where the rock is formed, it may have no molten magma. There are three types of crystals (glassy), microscopic crystals igneous rocks depending on the depth where (aphanitic), large crystals (phaneritic), or magma cooled and solidified. Intrusive or combinations of large and small crystals plutonic igneous rocks cooled slowly at great (porphyritic, aphanitic-porphyritic). depths, therefore they have large crystals. Fragmental igneous rocks also occur as Extrusive or volcanic igneous rocks solidified ejected igneous mineral. rapidly on the earth’s surface, producing small or no crystals. Hypabyssal igneous rocks solidify at medium depths. The answer is A. 63. Metamorphism is the process wherein rocks are subjected to intense temperature and pressure. Metamorphism induces a chemical change in the mineral composition of these rocks. New rocks (metamorphic rocks) are then formed. Image from http://www.knowledgerush.com The answer is C. The answer is B. 24 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 67. Superposition states that the oldest 72. Quartz can resist weathering as it is the sedimentary rock layers lie at the bottom, hardest common mineral. while the youngest rock layers are at the top. The answer is D. The answer is C. 73. As rocks weather into smaller sediments, 68. Clay is not a rock, it is a sediment. Shale is a these sediments are eroded and can combine sedimentary rock that metamorphoses into with organic debris. This produces soil, a slate. Limestone is another sedimentary rock nutrient-rich medium where most terrestrial that metamorphoses into marble. Granite is an autotrophs get their water and minerals. It also igneous rock that metamorphoses into gneiss. serves as a habitat for most terrestrial heterotrophs. The answer is D. The answer is C. 69. Mechanical weathering takes place when 74. Exfoliation is a form of mechanical rocks are broken down without any change in weathering due to uneven contraction and the chemical nature of the rocks. The rocks are expansion of rock. essentially torn apart by physical force, rather than by chemical breakdown. The most common type of mechanical weathering is the constant freezing, and thawing of water. The answer is C. 70. Choices A, B and C are major factors that cause mechanical weathering. The answer is D. 71. As water freezes in joints or cracks in rocks, it expands. As it requires more space, the cracks grow larger, eventually breaking apart the rock. This process is called frost wedging, a form of mechanical weathering as it breaks apart a rock without changing its mineral composition. Image from http://geodat.co.uk The answer is C. GENERAL SCIENCE TIP:  Chemical weathering dominates in warm, humid climates. Image from http://mail.colonial.net  Physical weathering dominates in cold, humid climates (good for frost wedging). The answer is A. 25 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 75. As explained in the previous item, exfoliation 77. Both physical weathering and chemical is a form of mechanical weathering. weathering reduce the structural integrity of rock. The result is that these rocks may break Chemical weathering happens when the up into smaller pieces. minerals of which the rock is made are changed, leading to the disintegration of the The answer is C. rock. It tends to affect certain minerals selectively, and although there are several different types of chemical weathering, 78. The flat floodplain signifies that the land including oxidation, hydration, hydrolysis, around the river has been well eroded. The carbonation, solution, chelation and the river, which is the main agent of erosion in this effects of acid rain, the different forms tends case, must have been present for a long time. to operate together. The oxbow lake is lake produced when the curve of a meander is separated from the main Oxidation, as the name suggests, occurs upon river body. The lake has a characteristic contact of the rock with oxygen, from the air or crescent shape. from water. A common effect is the rusting of rocks containing iron, as blue-grey becomes reddish-brown when ferrous compounds are oxidised. The chemical structure of the rock is altered by oxidation, making it more susceptible to other forms of weathering. Hydration simply involves the absorption of water into the existing minerals of the rock, causing the expansion of the mineral, leading to eventual weakening. It is less severe than hydrolysis, the most significant chemical weathering process, whereby H+ and OH ions in water react with the mineral ions. Carbonation is a result of the reactions of rainwater and carbon dioxide to produce Image from http://z.about.com carbonic acid (H2CO3), which slowly dissolves any rocks made of calcium carbonate, such as limestone. The answer is C. The answer is B. 79. A young river will have less erosion, as it has been present for only a short time. The 76. The main agent responsible for chemical riverbanks will then be steep. The sloping weathering reactions is water and weak acids terrain can contribute to increased speed of formed in water. the river. The answer is A.  An acid is solution that has abundant free H+ ions.  The most common weak acid that occurs in GENERAL SCIENCE TIP: surface waters is carbonic acid.  Carbonic acid is produced in rainwater by  Gravity is the force that drives erosion. reaction of the water with carbon dioxide  Streams are currently the number one agent of (CO2) gas in the atmosphere. erosion in New York State.  Stream velocity depends on slope (gradient) and discharge.  H+ is a small ion and can easily enter crystal  Velocity is greatest on the outside of meander bend. structures, releasing other ions into the water. The answer is C. 26 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 80. Because nitrogen is inert, it can compose a 82. The layer of the atmosphere that contains the large percentage of our atmosphere without thinnest (least dense) air is the causing negative effects to life and, thus thermosphere. It is also the hottest layer (due largely contributes to the air pressure on Earth to ions, H + and He - , that directly absorb necessary to support our bodies. the sun’s radiation). The atmosphere is composed of 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.03% carbon dioxide and 0.01% of other gases like neon, helium, methane, krypton, nitrous oxides and hydrogen. Image from http://www.sdm.scot.nhs.u The answer is A. 81. When cold air moving up from the poles encounters warm moist air moving down from the tropics, a cold front develops and the warm moist air rises above the cold front. This rising moist air cools as it rises causing the Image from http://www.enchantedlearning.com condensation of water vapor to form rain or snow. Note that the cold air masses tend to The answer is C. circulate around a low pressure center in a counterclockwise fashion in the northern 83. The presence of ozone in the stratosphere hemisphere and clockwise in the southern results to an increase in temperature as altitude hemisphere. Such circulation around a low increases. Ozone (O3) is formed from the pressure center is called a mid-latitude union of O2 and single O molecules. Solitary O cyclone. molecules are generated when UV light breaks down O2. The answer is B. 84. The mesosphere is the coldest layer of the earth’s atmosphere and it is where most meteors burn up. The answer is C. GENERAL SCIENCE TIP:  Winds curve to the right in the northern hemisphere and to the left in the southern hemisphere due to Image from http://www.inthewakeofthebelgica.com the earth rotation – called the Coriolis Effect. The answer is C. 27 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 85. This equilibrium causes in zero net flow of 86. As height increases, the gravity of the earth gases in or out of the body. If pressure weakens. The gas molecules become fewer as outside is greater, air would rapidly flow into height increases. If there are fewer molecules, our bodies (which, if it happens, will certainly there is less substance that can exert pressure. be felt). If pressure inside our bodies is Hence pressure also decreases as height greater, there would be a rapid flow of air out increases. of the body. Air pressure never has this effect because our bodies are hollow and our lungs are full of air, so the air presses equally on the inside and outside of our body at the same time. That's why we don't feel air pressure in the same way we feel water pressure. The answer is A. GENERAL SCIENCE TIP:  As temperature increases, air pressure decreases.  As atmospheric moisture (humidity) increases, atmospheric pressure decreases.  Air pressure decreases with altitude.  Cooler and drier air generally exerts higher pressure. Image from http://eo.ucar.edu  Warm, moist air generally exerts lower pressure. The answer is B. 87. In the atmosphere, convection includes large- and small-scale rising and sinking of air masses and smaller air parcels. These vertical motions effectively distribute heat and moisture throughout the atmospheric column and contribute to cloud and storm development (where rising motion occurs) and dissipation (where sinking motion occurs). The answer is A. Image from http://www.kudzuacres.com 28 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 88. Under normal conditions, excess heat from the sun (in the form of radiation) is reflected by the earth’s surface back to space. However, accumulation of carbon dioxide in the atmosphere prevents this process. The reflected heat by the earth’s surface is bounced back by the CO2 in the atmosphere back to the earth. This is the greenhouse effect. Image from http://www.myclimatechange.net The answer is D. 89. Most UV light is lost when it hits the ozone 90. Modern jet planes fly in the bottom portion of layer as its energy is consumed in the splitting the stratosphere. of ozone into O2 and O. The O2 and O recombines back to ozone. Image from http://ozone.gi.alaska.edu Image from http://www.windows.ucar.edu/ The answer is C. The answer is A. 29 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 91. At a specific temperature, the dew point, water vapor in the air would begin to condense. Dew point would differ according to the amount of water vapor on the air. If there is little water vapor in the air, the dew point is lower. If the water vapor amount is high, the dew point is also high. The answer is D. Image from http://biomet.ucdavis.edu 92. The dew point is used a lot by TV meteorologists and seen on most current weather conditions because it's a great indicator of the moisture content of the air, or humidity. The higher the dew point temperature, the higher the humidity. Since Air mass A has higher humidity (80% saturated), it means that it has higher dew point. The answer is B. 93. No conclusive statement about rain can be made. The answer is D. 94. If you have spent much time at the beach during the summer at the beach, absorbing UV radiation to darken your skin or just beachcombing, you've probably noticed that at around 3:00 p.m. there often is a strong steady wind blowing in from the water. This steady wind, the sea breeze, is a result of the uneven heating during the daytime between the land and the adjacent water. At night the wind often reverses direction and blows from the land to the water (a land breeze). Land and sea breezes are referred to as direct thermal circulations. Image from http://www.free-online-private-pilot-ground-school.com The answer is D. 30 | P a g e REVIEW MASTERS LEAGUE, INC. SCIENCE REVIEW ©2011 www.upcatreview.com 97. The sun was born about 4.6 billion years ago 95. When we speak of the surface of the Sun, we and will remain much as it is for another 5 normally mean the photosphere. billion years. Then it will grow to become a red giant. Late in the sun's lifetime, it will cast off its outer layers. The remaining core is called a white dwarf. Eventually, the white dwarf will slowly fade to become a black dwarf. The answer is D. 98. Phases of Moon Image from http://stargazers.gsfc.nasa.gov The answer is C. 96. The solar wind is a stream of energized, charged particles, primarily electrons and protons, flowing outward from the Sun, Image from http://www.theplantexpert.com through the solar system at speeds as high as 900 km/s and at a temperature of 1 million The answer is D. degrees (Celsius). It is made of plasma. 99. Pluto orbits beyond the orbit of Neptune The solar wind is caused by the hot solar (usually). It is much smaller than any of the corona, which is the outermost layer of the official planets and now classified as a solar atmosphere, expanding into space. The "dwarf planet". corona is the "rim" of the Sun that is visible to the naked eye during a solar eclipse. The answer is C. 100. Earth’s axis is tilted at an angle of 23.5. Image from http://www.americanscientist.org Image from http://divulgence.net The answer is D. The answer is B. 31 | P a g e