This document contains a test with multiple choice questions about science topics such as the human body, plants, animals, weather, and the environment. The test instructs examinees to choose the correct answer for each question and blacken the corresponding letter on an answer sheet without writing on the test itself. It consists of 58 questions ranging from topics like photosynthesis, the water cycle, and electricity safety.

1. Direction. Each item in this test consists of four (4) options. Choose the correct
answer, blacken the letter that corresponds to your answer sheet. Do not write
anything on this questionnaire.
1. Blums is observing two stones -- one was placed in the shade and
the other was placed under the sun. Which part of his body helps
him feel the temperatures of the stones?
a. nails b. skin c. hair d. bones
2. Peristalsis is the mechanical process by which food is thoroughly
mixed with the digestive juices and pushed through the alimentary
canal. Which of the following would best describe chyme, the partly
digested food in the stomach?
a. flattened c. coarse and fibrous
b. Cut into pieces d. thick and pasty
3. Good eating habits is essential to good nutrition. When eating
your meals, what should you do to avoid having indigestion?
a. Eat more than enough. c. Talk as much as you can.
b. Chew your food well. d. Eat just enough.
4. Disease-causing microorganisms have always been man's
enemies. Which of the following did man invent to strengthen his
body against disease causing microbes?
a. Immunization c. conservation
b. Pasteurization d. fertilization
5. Photosynthesis is the food-making process in green plants. Which
of the following is not essential in photosynthesis?
a. Water b. air c. nitrogen d. sunlight
6. If you visit a beautiful garden, you will most likely see bees and
butterflies flying from flower to flower. In what way do these insects
help the plants?
a. They protect the plants. c. They help in pollination.
b. They beautify the garden. d. They help the plants grow.
7. Tadpoles are young frogs. Why can tadpoles live in water?
a. They have gills for breathing. c. They have scale all over the
body.
b. They have long slim body. d. They have tails for swimming.
8. Traditional farming makes use of animals more than the modern
agricultural equipments. Which group of animals is used to plow the
field?
a. Dog and cow c. horse and dog
b. caribao and cow d. carabao and goat

2. 9. Hunters have keen eyes, sharp ears, and extraordinary sense of
smell. What would be the possible reason for the hunters missing
the crocodile in the muddy water? a. The crocodile is so small. c. The
crocodile is not making any sound.
b. The crocodile is not moving. d. The crocodile is as dark as the
muddy water.
10. Flies and other pests is a nuisance in the home and community.
Which practice helps in eliminating pests?
a. Paint the room. c. Put plants in the room.
b. Keep the room clean. d. Spray the room with air freshener
11. Which order shows the correct stages in the development of a
butterfly?
a. Larvae- eggs-chrysalis-pupa-adult c. egg-larvae-chrysalis-pupa-
adult
b. Egg-chrysalis-larvae-adult-pupa d. egg-adult-larvae-chrysalis-
pupa
12. Pollution threatens our drinking water, destroys the life-
sustaining soil, and corrupts the breathable air. Which of the
following may likely contribute to water pollution?
a. Distillation of salt water. c. Waste disposal in the rivers.
b. Burning of garbage in pits. d. Removing water lilies in the river.
13. Why is water called the universal solvent?
a. It is found anywhere. c. It can easily dissolve most substances.
b. It is safe for drinking. d. It is needed by all living things.
14. The earth's lithosphere is made of rocks of different kinds. What
kind of rock is formed by underground heat and pressure?
a. igneous rock c. metamorphic rock
b. bedrock d. sedimentary rock
15. Which of the following will help prevent air and water pollution?
a. Bury garbage. c. Let stray animals eat our garbage.
b. Burn garbage. d. Throw garbage in esteros or canals.
16. A force is either a push or a pull. It can start motion, stop motion,
or change its direction. What happens if force is applied to a fast
moving object?
a. Object stops immediately.
b. Object continues moving before it stops.
c. Object changes direction before it stops.
d. Object turns back to where it started.

3. 17. Population affects a community in many ways. What will most
likely happen if more families come to live in your barangay?
[A] There will be less space for houses.
[B] There will be more recreational facilities.
[C] There will be more buses and jeeps.
D] There will be big enrolment in schools.
[E] There will be more garbage.
a. A, B & C b. A,D & E c. C, D & E d. B, C & D
18. What will be the most likely temperature reading of a person
wearing a thick sweater?
a. 30OC b. 37OC c. 25OC d. 20OC
19. What force causes objects to move toward the ground?
a. gravity b. friction c. inertia d. magnetism
20. As far as we know, the earth is the only planet that can support
life. The primary reason why men, plants and animals can live on
Earth is that it
a. has the gases and sunlight needed by plants.
b. has oxygen needed by man for breathing.
c. is neither near nor far from the sun.
d. is rich in material resources.
21. What objects travel around the sun between the orbits of Mars
and Jupiter?
a. asteroids b. comets c. meteors d. planets
22. What causes the succession of day and night on Earth?
a. Rotation of the sun. c. Rotation of the moon.
b. Rotation of the earth. d. Rotation of the clouds.
23. Which is the easiest way of loading a concrete pipe on a truck?
a. Put a long ramp against the truck. Roll the pipe up the ramp.
b. Put a short ramp against the truck. Roll the pipe up the ramp.
c. Tie a rope around the pipe. Pull the pipe by the rope.
d. Lift the pipe with bare hands.
24. Conserving electricity at home is our own way of helping prevent
an energy crisis. Which of the following would you do to conserve
electricity?
a. Iron clothes everyday.

4. b. Leave the radio and television on the whole day
c. Switch on the light while sleeping.
d. Turn off appliances when not being used.
25. Seasons affect our lives and lifestyles. What we do during winter
is different from what we do in summer. For example, during summer
the kind of clothes that we will likely want to wear is
a. black and thick clothes. c. white and thin clothes.
b. white and thick clothes. d. black and thin clothes.
26. Population density refers to the number of individuals in a given
land area. A higher population density necessarily means a crowded
area. What happens when houses are too close to each other?
a. Many store should be put up. c. Cleanliness and sanitation
become a problem.
b. There are more literate people. d. Surroundings become
pleasant to look at.
27. Why is Earth the most interesting and useful planet for us?
a. It is the most beautiful planet. c. It is the planet on which we live.
b. It is the planet closest to the sun. d. It is bigger than the sun.
28. Which planet is nearest to the sun?
a. Venus b. Mercury c. Mars d. Earth
29. Why can baby catterpillars live without their mother?
a. They can fly to find the food. c. They can build a place to live.
b. They can eat the leaves of plants. d. They can trap their
enemies.
30. Pollination in flowers takes place when
a. butterflies carry pollen grains from the anther to the stigma of
another flower.
b. insects are attracted by their color and odor.
c. bees sip the pollen grains.
d. ants sip the nectar on the petals.
31. There are different ways by which animals protect themselves
from their enemies. The color of an animal, for example, is a way of
a. distracting the enemies. c. making the animal look attactive.
b. making the sorroundings beautiful. d. making the animal look like
its surroundings.
32. What will happen to water when placed in the freezer of the
refrigerator?

5. a. It contracts and changes to solid. c. It expands then contracts as
it changes to solid.
b. It expands and changes to solid. d. It contracts then expands as
it changes to solid.
33. Which of the following are the correct and safe practices when
working with electricity?
[A] Never touch the switch with wet fingers.
[B] Live electric wires should not be touched with bare hands.
[C] Touch a bare electric wire dangling from a pole.
[D] Put your finger inside an electric socket.
a. A, C & D b. B, C, & D c. C & D d. A & B
34. Which process involves the raising of milk to a higher
temperature in order to kill the harmful bacteria?
a. chlorination c. evaporation
b. preservation d. pasteurization
35. Living things have the ability to respond to certain stimuli.
Hydrotropism, for example, makes the roots of plants move to where
there is water. Why do stems of most plants grow upward?
a. To make food from air.
b. To hold leaves toward the sunlight.
c. To absorb more water in the leaves.
d. To absorb air from the surrounding.
36. The Grade three pupils planted mongoes in small pots.
One mongo plant was placed inside and another outside the
room. The plant outside the room was healthy and green, while
the one inside was thin and pale. This setup shows that the
plants need
a. shade b. air c. sunlight d. water
37. What kind of rocks are formed in layers from materials deposited
by wind and water?
a. sediment b. metamorphic c. igneous d. marble
38. What causes a flying kite to change its direction?
a. The force of the wind. c. The force of the sky.
b. The force of the clouds. d. The force of the earth.
39. Primitive men learned how to produce fire by friction. When
rubbing pieces of stick together to produce fire, what kind of energy
is involved?

6. a. chemical b. mechanical c. electrical d. nuclear
40. Suppose you were asked to help get the large pipe from the canal
onto the road. What is the best thing to do?
a. Use a pole to lift the pipe. c. Use a slanted board to lift the pipe.
b. Bring the pipe up by pulling it. d. Use a pulley to lift the pipe.
41. Simon discovered, while swimming, that it easier to lift a big rock
underwater than on land. Which of the following best explains his
observation?
a. The water pushes the rock upward.
b. The rock becomes lighter when wet.
c. Force of gravity on the rock underwater is less.
d. Air in the pores of the rock is displaced by water.
42. The pupil of the eye controls the amount of light entering our
eyes. What happens to the pupil when you are in a dark room?
a. The color of the pupil changes. c. The pupil becomes bigger.
b. The shape of the pupil changes. d. The pupil becomes smaller.
43. Calcium is an important mineral found in nature. It is used as one
of the building materials for our body's framework. In which part of
the body is calcium mostly deposited?
a. muscle b. blood c. bone d. cell
44. What becomes of a rock that is acted upon by the earth's
tremendous heat and pressure?
a. igneous b. basaltic c. metamorphic d. sedimentary
45. Which statement or statements below is/are true about air?
[A] Air is a mixture of several gases.
[B] The normal components of air are oxygen, carbon dioxide, water
vapor, nitrogen and inert gases.
[C] Dust is an accidental component of air.
a. A only c. B & C only
b. A & B only d. A, B and C
46. Extreme care must be observed when dealing with fire. If a can of
kerosene is on fire, which of the following is the safest thing to do?
a. Pour water. c. Beat the flame with wet rag.
b. Cover the can. d. Topple the can to spread the kerosene.

7. 47. The earth is surrounded with layers of air called the atmosphere.
Without the atmosphere, no living thing can survive and the
temperature of the earth's surface will be very
a. cold throughout the day and night.
b. hot throughout the day and night.
c. very cold at night and very hot during the day.
d. hot at night and very cold during the day.
48. Relative humidity, expressed in percent, refers to the amount of
water present in the air at any given time and temperature. At which
humidity level will you feel warmest?
a. 50% b. 65% c. 75% d. 85%
49. Blood is the transport medium of our body. It carries food and
oxygen to all parts of the body. It also delivers carbon dioxide and
other waste materials to their corresponding excretory organs. How
will you describe the blood after passing through the lungs?
a. It is rich in oxygen and low in carbon dioxide.
b. It is rich in carbon dioxide and low in oxygen.
c. It is rich in both oxygen and carbon dioxide.
d. It is low in both oxygen and carbon dioxide.
50. Lightning is one of the most frightening occurrences during a
thunderstorm. Yet it causes a change in the atmosphere which
favors plant growth. What is this change?
a. The oxygen and hydrogen in the air combine to form water which
is needed by plants.
b. The nitrogen in the air changes into a substance needed by
plants.
c. Air pollutants are changed into substance which are needed by
plants.
d. The oxygen in the air changes into ozone needed by plants.
51. If you were thirsty and stranded in the open sea with no supply of
drinking water, should you drink seawater? Why?
a. No, because seawater contains poisonous chemicals.
b. No, because drinking seawater will speed up the drying out of
body cells.
c. Yes, because seawater will keep their body cells from drying out.
d. Yes, because the salt from seawater will destroy disease
microorganisms.

8. 52. Spring, summer, autumn and winter are the four seasons in some
countries. In the Philippines, we have two seasons: wet and dry.
Which statements below explain why seasons change?
[A] The earth revolves around the Sun.
[B] The earth is made up of continents and bodies of water.
[C] The earth rotates on a tilted axis.
a. A & B b. B & C c. A & C d. A, B and C
53. Bottles A and B are alike in all ways except that bottle A is filled
with oil and bottle B is filled with an equal amount of water. If the two
bottles are tilted at the same angle from the same height to allow the
contents to flow, which bottle will be emptied first? Why?
a. A, because the pull of gravity is greater on the oil than on the
water.
b. A, because there is greater attraction between the molecules of
oil than between the water molecules.
c. B, because the pull of gravity is greater on the water than that on
the oil.
d. B, because there is lesser attraction between the molecules of
water than between the oil molecules.
54. Suppose there was a fire, and you were caught inside your room
that is is filled with thick smoke, what is the best thing for you to do?
a. Crawl out of the room. c. Cover your nose.
b. Run out of the room. d. Stay calm and call for help.
55. Insects help in the fertilization of flowering plants by
a. scattering seeds. c. eating fruits.
b. sucking nectar. d. pollinating flowers.
56. Cooking oil in a frying pan gets hot faster than the same amount
of water. Which of the following explains this observation?
a. Water is denser than cooking oil.
b. Water has a lower kinetic energy than cooking oil.
c. Cooking oil has a higher boiling point than water
d. Cooking oil has a lower specific heat than water.
57. Ozone is a form of oxygen that is present in the upper
atmosphere. It is threatened by pollution, particularly the CFC's. The
destruction of the ozone layer is a serious environmental problem.
What is the importance of the ozone layer to living organisms on
Earth?
a. It regulates air temperature.
b. It is important in rain formation.

9. c. It is needed in the production of oxygen in the air.
d. It is reduces the ultraviolet rays reaching Earth.
58. We are affected by such changes in weather conditions as
typhoons, drought and others. Thus, weather forecasting becomes
an essential aspect of our daily lives. Fortunately, there are
instruments that help us predict the weather. Which of the following
sets of instruments may be used to predict typhoons?
a. thermometer, hydrometer, wind vane, barometer
b. thermometer, hygrometer, wind vane, barometer
c. thermometer, altimeter, seismograph, barometer
d. thermometer, hygrometer, seismograph,barometer
59. Which statement is true for all planets in our solar system?
a. Each planet has at least one moon.
b. Each planet is covered with an atmosphere.
c. All planets revolve around the sun with the same speed.
d. All planets exert different amounts of gravitational force.
60. Tani observed that the storekeeper raises the funnel slightly
when pouring kerosene into a bottle. He became curious and asked
why. Which of the following is the correct explanation for his
observation?
a. To allow air to enter the bottle.
b. To prevent the tilting of the funnel.
c. To prevent the vinegar from spilling.
d. To allow air to escape from the bottle.
61. You are to carry two pails of the same size. One is filled with
water and the other is filled with sand. Which is easier to carry?
Why?
a. The pail of sand, because there are more air spaces in it.
b. The pail of sand, because it is lighter than a pail of water.
c. The pail of water, because it is lighter than a pail of sand.
d. The pail of water, because water particles are finer than sand
particles.
62. If you were on a beach, you will notice that a gentle wind blows
from the sea to the land. This is called the sea breeze. The sea
breeze is stronger when the temperature over the land
a. is the same as that over the sea.
b. is much warmer than that over the sea.

10. c. is much cooler than that over the sea.
d. changes faster than that over the sea.
63. Water-borne diseases are those diseases caused by
microorganisms when dirty water is taken in. Which group of
diseases may result from water-borne microorganisms?
a. Cholera, dysentery, typhoid, cancer.
b. Cholera, dysentery, typhoid, malaria.
c. Hepatitis, dysentery, typhoid, cholera.
d. Hepatitis, malaria, diabetes, polio.
64. Perspiration helps regulate our body temperature. When sweat
evaporates, you feel cooler because heat is taken away from the
body. When sweat does not evaporate, you feel warm and
uncomfortable. Which of the following describes the conditions of
the weather when sweat remains on the skin?
a. hot and dry c. cold and humid
b. hot and humid d. cold and dry
65. Harmful bacteria and viruses are often referred to as "microbes".
They can invade the body and cause illness. Normally, how do
microbes enter the body?
[A] through the air we breathe.
[B] through the food and water we drink.
[C] through wounds in our skin.
[D] through injected medicines.
a. A & B only c. A, B and C
b. B & C only d. B, C and D
66. Our body uses oxygen in changing the food we eat into energy.
This energy is used by the body in many activities. In which of the
following activities does our body use the least amount of oxygen?
a. Walking b. Running c. Swimming d. Jogging
67. Which combination of processes will enable you to obtain fresh
water from sea water?
a. evaporation and filtration c. evaporation and condensation
b. filtration and condensation d. precipitation and condensation
68. The atmosphere contains a certain gas which can be changed
into another substance by the action of bacteria. The new substance
can then be absorbed by plants through their roots. Which gas is
this?
a. oxygen b. hydrogen c. nitrogen d. carbon dioxide

11. 69. Why is the freezer always found in the upper portion of any
refrigerator?
a. To make it easy to put in and remove things from the freezer.
b. To allow better circulation of cold air coming from the freezer.
c. To prevent young children from being exposed to cold air from
the freezer.
d. To prevent the delicate coils of the freezer from being hit
accidentally when placing other foods.
70. Rice, fruits, vegetables and meat are called food because they
a. are easily absorbed by the body.
b. are easily digested in the body.
c. keep the body temperature constant.
d. supply energy and building materials to the body.
71. All animals need to oxygen to live. With the exception of the fish,
all animals get the oxygen from the air. The fish take in oxygen while
underwater. Where does this oxygen come from?
a. From the decomposition of organic matter in the water.
b. From oxygen that is dissolved in the water.
c. From carbon dioxide that splits into carbon and oxygen.
d. From the water molecule that splits into hydrogen and oxygen.
72. A boy is digging a hole in the sandy beach. At a certain depth,
water comes out and fills the hole. What kind of water is it? Why?
a. Fresh, because layers of sand filter out salt in seawater.
b. Fresh, because the water that comes out is rainwater that has
been absorbed by the sand.
c. Salty, because salt in seawater that seeps into the sand is not
filtered out by the sand.
d. Salty, because salt in the sand particles has been dissolved in
water.
73. Which of the following takes the same time to complete?
[A] one revolution of the earth around the sun.
[B] one revolution of the moon around the earth.
[C] one rotation of the earth about its axis.
[D] one rotation of the moon about its axis.

12. a. A and C b. B and D c. A, B and D d. B, C and D
74. Some materials float in water while others sink. If you were to
determine whether a material will float or sink in water without
actually putting it in water, which of the following will you measure?
a. weight b. volume c. density d. center of gravity
75. Coal and oil are our main sources of fossil energy. If you were to
trace the processes involved in the formation of this energy, which
of the following will be the starting point?
a. ocean b. sun c. rocks d. living things
76. Plants kept inside a closet die after sometime because of lack of
a. air. b. food. c. moisture. d. heat.
77. The atmosphere is a mixture of gases that envelopes the earth.
Which statements are true about the earth's atmosphere?
[A] The atmosphere contains substances necessary to sustain life.
[B] The atmosphere is denser at the top of the highest mountain than
on lowlands.
[C] The conditions of the atmosphere are used in predicting the
weather.
[D] The atmosphere protects us from the harmful effects of the sun's
radiation.
a. A, B, C b. A, C, D c. A, B, D d. B, C, D
78. Eating builds and repairs body tissues and supplies the body
with energy. What happens when you habitually overeat?
a. You become stouter and more healthy.
b. You become stouter and less active.
c. You become taller and more healthy.
d. You become taller and less active.
79. Which of the following statements can be the reason why
drinking water is safer when it is boiled or chlorinated?
a. Boiled or chlorinated water is free from dirt.
b. Toxic materials can be removed by boiling and chlorinating
water.
c. Germs are killed when water is boiled or chlorinated.
d. Boiling or chlorinating gives water a pleasant taste.
80. Which of the following may happen during an earthquake?
a. High tides occur.

13. b. Strong winds are produced.
c. Ground surface breaks open.
d. Lava flows on the earth's surface.
81. From the time the solar system was born, Earth has been
continually receiving heat from the sun. Which of the following
reasons explain why Earth does not become as hot as the sun?
[A] Earth is much smaller than the sun.
[B] Earth is very far from the sun.
[C] Earth gives off much of the heat it receives from the sun.
a. A and B b. B and C c. A and C d. A, B and C
82. Why do we usually open the windows to get rid of odors in a
room?
a. To let sunlight enter and absorb the odors.
b. To allow the odors to spread out in the room.
c. To allow air to enter and carry away the odors.
d. To allow more air to enter and mix with the odors.
83. It has been observed that dengue-fever occurs more often during
the rainy months. Which practice will minimize the contracting and
spreading of the disease?
a. Avoid playing or bathing in the rain.
b. Avoid taking in dirty food and water.
c. Remove standing water from cans and canals.
d. Clean the breeding places of flies and cockroaches.
84. An eclipse is formed whenever there is an alignment of the moon,
the earth and the Sun . What is the position of these heavenly bodies
at the time of a total solar eclipse?
a. moon Earth sun
b. sun Earth moon
c. sun moon Earth
d. moon sun Earth
85. Electric wires are covered with insulating materials in order to
prevent a short circuit. When does a short circuit occur?
a. When electricity flows through one unexposed wire.
b. When the wires become heated up at the exposed portion.
c. When electricity flows directly from one exposed wire to the other
wire.

14. d. When electricity flowing through the exposed wires escape into
the air.
86. The cold winds we experience in the Philippines during the
months of December, January and February are due to the
a. cold winds coming from bodies of water surrounding the
Philippines.
b. cold winds moving towards the Philippines coming from cold
countries.
c. cold air in the upper atmosphere which moves downward at a
fast rate.
d. hot air in the lower atmosphere which rises and causes wind to
form.
87. Glass is one of the hardest substances known. Glass cutters
have a special tool containing a diamond tip. Why is diamond used
for cutting glass?
a. It is sharper than glass. c. It is harder than glass.
b. It is tougher than glass. d. It is stronger than glass.
88. Volcanic eruptions contribute to the degradation of the
environment. Which of the following materials from volcanoes
causes acid rain?
a. ash b. gases c. sand and stones d. red hot lava
89. Heat may be transferred in three different ways, namely
conduction, convection and radiation. In a classroom, heat transfer
is mainly by
a. conduction. c. conduction and radiation.
b. convection. d. convection and radiation.
90. Volcanic eruption is primarily due to
a. indiscriminate drilling and mining activities near volcanoes.
b. indiscriminate logging and cutting down of trees near volcanoes.
c. continuous buildup of pressure of hot underground materials.
d. continuous increase in temperature in the earth's interior.
91. In fish farming, it is important to maintain an ideal population of
fish in a given volume of water in a pond. When the population
density is unreasonably high, competition will most likely occur and
the yield will be smaller fishes. Which of the following practices will
prevent the overcrowding of fish in a pond?
a. Put more water plants. c. Put other kinds of much bigger fish.
b. Reduce the amount of feeds. d. Reduce the amount of water.
92. When you open a vacuum-sealed can, you hear a hissing sound.
The sound is produced by the sudden

15. a. release of air from the can.
b. flow of air into the can.
c. change in temperature of the contents.
d. change in volume of the contents.
93. Sunlight is white because it is made up of all colors, primarily the
blue, red and green. During photosynthesis, the chlorophyll of green
plants absorb some of these colors in order to break water into
hydrogen and oxygen. Which are these colors?
a. red and green c. green only
b. red and blue d. green and blue
94. Imagine that a part of a space satellite is suddenly detached while
it is in orbit. Which of the following best describes the motion of the
detached part?
a. It moves in straight line with a decreased velocity.
b. It moves in straight line with an increased velocity.
c. It continues moving in the same orbit with the same velocity.
d. It moves in a different orbit with the same velocity.
95. According to Johannes Kepler, a noted 17th century German
astronomer, the orbits of the planets are elliptical, not circular. If
Earth were to follow a perfectly circular orbit, which of the following
statements would be true?
a. Earth would revolve faster about the sun.
b. Earth would revolve slower about the sun.
c. Earth would be sometimes nearer, sometimes farther from the
sun.
d. Earth would always be at the same distance from the sun.
96. All plants need water, sunlight, minerals and carbon dioxide.
Which of these factors limit the growth of plants in most parts of the
world?
a. water b. sunlight c. minerals d. carbon dioxide
97. Gerard heated some substances for 5 minutes and measured
their volumes.The results are shown in the table below :
substance | before heating | after heating
===================================================
water | 50 ml | 54 ml
---------------------------------------------------
aluminum | 20 cm3 | 21.5 cm3

16. ---------------------------------------------------
iron | 30 cm3 | 30.5 cm3
---------------------------------------------------
air | 100 ml | 150 ml
---------------------------------------------------
Which substance expanded the most?
a. water b. iron c. wood d. air
98. A research is conducted to investigate the strength of hollow
blocks made from volcanic ash as compared to hollow block made
from sand. Which of the following 4 possible mixtures should be
compared with a mixture of cement, water, and volcanic ash?
a. cement, water, and sand c. cement and water,
b. cement and volcanic ash d. cement, water, sand, and volcanic
ash
99. Which of the following can you infer when you see molds on
bread?
[A] The bread is old.
[B] The bread serves as food for the molds.
[C] There is moisture in the bread.
[D] There are molds in the air.
a. A and B b. B and C c. C and D d. A, B, C, D
100. Not all microorganisms are harmful. Some bacteria and molds
are useful. In what way are they useful?
a. They serve as food for animals.
b. They serve as food for plants.
c. They cause the decay of dead plants and animals.
d. They help increase the amount of oxygen in bodies of water.
101. How does an electric fan make a person feel cool on a warm
day?
a. It cools down the surrounding air.
b. It brings cold air in contact with the body.
c. It blows warm air away from the body.
d. It speeds up evaporation of moisture from the body.
102. Why is food not readily spoiled when stored inside a
refrigerator?

17. a. Low temperature preserves the water level of food.
b. Low temperature slows down the growth of microorganisms.
c. Low temperature freezes the water content of food.
d. Low temperature prevents the production of toxic materials in the
food.
103. Pesticides are sprayed on fruits and vegetables in many farms.
Most pesticides have toxic ingredients which can be hazardous to
one's health. Which of the following should be done to lessen the
harmful effects of pesticides in one's body?
a. Wash fruits and vegetables before eating and cooking.
b. Expose fruits and vegetables to the air for several hours.
c. Dip fruits and vegetables in salt water for several hours.
d. Expose fruits and vegetables under the sun for several hours.
104. Waste is always part of every human activity. The waste
products of the body are water, carbon dioxide, urine and dissolved
salts. These are eliminated from the body through their respective
excretory organs. Which is not a correct pair of body waste and
excretory organ?
a. water and mouth c. carbon dioxide and nose
b. urine and anus d. dissolved salts and skin pores
105. Mongo seeds may be germinated in wet newspaper. Where do
the germinating seeds get their food?
a. water c. seed
b. newspaper d. sunlight
106. Food spoils. Which of the following will slow down the spoiling
of food?
[A] Drying [B] Smoking [C] Canning [D] Salting
a. A & B b. C & D c. A, B & C d. A, B, C & D
107. A tray with water is placed in a freezer in order to make ice. As
its temperature is decreased, water changes to ice. During this
process, is energy absorbed or given off? Why?
a. Given off, because decreasing the temperature slows down
water molecules.
b. Absorbed, because decreasing the temperature slows down
water molecules.
c. Given off, because decreasing the temperature speeds up the
molecules of water.
d. Absorbed, because decreasing the temperature speeds up the
molecules of water.

18. 108. Because of the earth's tilted axis, there are places near the north
pole where there is daytime 24 hours a day during summer. What is
the position of the earth with respect to the sun when this happens?
a. When the earth's north pole is facing the sun.
b. When the earth's north pole is away from the sun.
c. When the earth's poles are neither facing nor away from the sun
d. When the earth is farthest away from the sun.
109. Which of the following is the source of energy in almost all
ecosystems?
a. moving water c. plants
b. animals d. sun
110. Which of the following organisms cannot live in the dark?
a. bacterium b. fungus c. green plant d. virus
111. Light-colored clothes reflect more light than dark-colored ones.
Which of the following clothes would be most comfortable to wear
during summer?
a. black clothes c. bright red clothes
b. white clothes d. blue clothes
112. Black bodies are the better absorbers and radiators of heat than
white bodies. Which of the following clothes would be most
comfortable to wear during winter?
a. black clothes c. black clothes with white inner lining
b. white clothes d. white clothes with black inner lining
113. Why should drivers slow down when driving on a wet road?
a. To avoid skidding so that the tires will last longer.
b. To avoid skidding because friction between the tires and the wet
road is less.
c. To save on fuel because tires moving on wet road uses more
fuel.
d. To save on fuel because tires moving on wet road uses less fuel.
114. A wooden ball and an iron ball of the same size are given the
same push on a flat frictionless surface. Which ball will travel a
longer distance? Why?
a. The wooden ball because it has a smaller mass.
b. The iron ball because it has a bigger mass.
c. The wooden ball because it has a lower speed.
d. The iron ball because it has a greater speed.

19. 115. A 40-watt fluorescent lamp is better than a 50-watt incandescent
bulb because it provides a brigher illumination. Which of the
following statements is correct?
a. The bulb uses less electrical energy.
b. The bulb uses more electrical energy.
c. The fluorescent lamp uses more electrical energy.
d. The fluorescent lamp and bulb use the same amount of electrical
energy.
116. The following are clouds seen in the sky. Which are the basic
types of clouds?
[A] Cirrus [B] Cumulus [C] Stratus [D] Cumulunimbus
a. A & B only c. B & D only
b. A & C only d. A, B and C
117. Which of the following events generally accompany a volcanic
eruption?
[A] steam and smoke from cracks
[B] heavy rains
[C] underground noises
[D] lava flow from cracks and crater
a. A, B, C b. B, C, D c. A, C, D d. A, B, D
118. Which of the following energy sources does not get energy from
the sun?
a. geothermal c. oil
b. coal d. wind
119. Which of the following practices contribute to conservation of
energy?
[A] Turn off the lights when not in use.
[B] Whenever possible do all activities that need electric light in one
room.
[C] Iron all clothes at one time.
[D] Change 220 volt outlets to 110 volts.
a. A only b. A & B only c. A, B and C d. A, B and D
120. The food we eat is classified into three main groups : Go foods,
grow foods, glow foods. Which group or groups provide us with
energy?
a. go foods c. glow foods

20. b. grow foods d. All of the above
121. Light is a form of energy. Which of the following organisms in a
farm can get energy for its activities directly from light?
a. carabao b. ricebird c. grasshopper d. rice plant
122. The surface of a shallow pond is covered with water lily. If no
water flows into the covered pond what will happen to it after
sometime?
a. The pond will dry up.
b. The amount of water in the pond will not change.
c. The amount of water in the pond will increase.
d. The water in the pond will become salty.
123. Floods usually bring such diseases as cholera, dysentery, and
typhoid fever. How does a person become infected with cholera?
[A] By drinking contaminated water.
[B] By using dirty needle for injection.
[C] By eating contaminated food.
[D] By blood transfusion.
a. A & B b. A & C c. B & D d. A & D
124. About how long would it take a rocket ship to reach the moon?
a. two hours b. a light-year c. several years d. a few days
125. Statistics showed that at least one person dies of dog bite
everyday. Dogs are immunized against a disease called
a. distemper. b. rabies. c. pneumonia. d. parasitism.
126. For one reason or another, the "pawikan" is an endangered
species in our country. This means its population is continuously
decreasing. Which will help the pawikan from becoming
endangered?
[A] Preserve its natural habitat.
[B] Do not disturb the marine food chain.
[C] Do not hunt it for economic gains.
a. A only b. B only c. A & B only d. A, B and C
127. Formalin is a chemical used to preserve dead bodies. It kills
microorganisms that cause decay. Unfortunately, some also use it
for preserving some food. Which of the following foods are likely to
be treated with formalin?
a. Fish only c. Fish and vegetables only
b. Vegetables only d. Fish, vegetables, rice and corn

21. 128. Victims of amoebiasis suffer from diarrhea. They may die from
excessive dehydration or loss of water. Which should be done to
avoid the disease?
[A] Boil drinking water.
[B] Make sure the food eaten is clean.
[C] Wash the hands with soap and water before eating and after
using the toilet.
a. B only b. C only c. B & C only d. A, B and C
129. After a flood, drinking water supply may become polluted.
People are advised to boil water before drinking it. Which of the
following describes the action of boiling?
a. It kills many microbes in the water.
b. It removes chemical pollutants by evaporation.
c. It makes soil and other dirt settle fast.
d. It removes the bad odor of the water.
130. When cooking rice, mists or clouds form above the cooking pot.
What are the mists made of?
[A] water from the boiling rice.
[B] water from the surrounding air.
[C] water and other substances from the surrounding air.
a. A only b. B only c. A & B only d. A & C only
131. Which food, uncooked rice or loaf bread, is more easily spoiled
by microorganisms? Why?
a. Rice, because it contains less sugar.
b. Rice, because it contains more moisture.
c. Bread, because it contains less sugar.
d. Bread, because it contains more moisture.
132. Bleeding occurs whenever a blood vessel such as a vein or an
artery is ruptured. As one of the body's protection against accidental
cuts, veins and arteries are buried deep within the skin. Why is it that
bleeding results from even a slight scratch on the skin?
a. Tiny blood tubes known as capillaries are cut.
b. The skin contains nerve fibers that are also blood tubes.
c. When a skin is cut, the pressure over a bood vessel decreases
and a little blood flows out by osmosis.
d. There is actually no bleeding. When a skin is slightly cut, a
chemical reaction takes place between the air and some body fluids
causing the formation of a red fluid that looks like blood.

22. 133. Modern farming discourages the use of chemical fertilizers
because they are toxic to the living organisms that thrive in the soil.
These organisms help fertilize the soil the natural way. A soil with
organisms is commonly called a living soil. A child wants to know
what small organisms live in the soil in their garden. Where should
he get the soil sample?
[A] topsoil [B] subsoil [C] parent rock
a. A only b. B only c. A & B only d. A & C only
134. Three glass tumblers are filled with water at different
temperatures. On which tumbler will you see water droplets after
sometime?
[A] cold water @ 50 C [B] tap water @ 250 C [C] hot water @ 500 C
a. A only b. A & C only c. B & C only d. A, B & C
135. The Sun is visible to us because it emits light. At night, we can
also see the stars because they also emit light. Why can we see the
Moon?
a. It reflects light from the Sun. c. It also emits light.
b. It is without an atmosphere. d. It is nearer the Earth than the
Sun.
136. A girl found the skull of an animal. She did not know what the
animal was but she was sure that it preyed on other animals for its
food.
a. The skull was much longer than it was wide.
b. There was a projecting ridge along the top of the skull.
c. Four of the teeth were long and pointed.
d. The jaws could move sideways as well as up and down.
137. There are many factors affecting pulse rate and breathing
rate.To investigate the effect of exercise, pulse and breathing rates
are taken before and after an exercise. What changes would you
expect to find?
a. no change in pulse but a decrease in breathing rate
b. an increase in pulse but no change in breathing rate
c. an increase in pulse and breathing rate
d. a decrease in pulse and breathing rate
138. Which of the following statements is true about seeds?
a. Every plant produces seeds.
b. All fruits contain a large number of seeds.
c. All seeds are good to eat.
d. Every seed contains a young plant, stored food and a seed coat.

23. 139. Flowers cannot usually produce seeds unless
a. they are visited by insects.
b. they are on plants growing in good soil.
c. they produce nectar.
d. the right pollen is placed on their stigmas.
140. Some seeds germinate best in the dark, others in the light, while
others germinate equally well in the dark or the light. To investigate
to which group a certain kind of seed belongs, put some of the seeds
on damp newspaper and
a. keep them in a warm place in the dark.
b. keep one set of seeds in the light and another in the dark.
c. keep them in a warm place in the light.
d. put some on dry newspaper and keep them in the light.
141. When milk decays, it goes sour. Why does it not go sour when
stored in a refrigerator?
a. The cold changes the water of the milk into ice.
b. The cold separates the cream.
c. The cold slows down the action of bacteria.
d. The cold causes a skin to form on the surface of the milk.
142. How does paint, applied to an iron surface, prevent the iron from
rusting?
a. It prevents nitrogen from coming in contact with the iron.
b. It reacts chemically with the iron.
c. It prevents carbon dioxide from coming in contact with the iron.
d. It prevents oxygen and moisture from coming in contact with the
iron.
143. Maria and Nena each bought the same kind of rubber ball. Maria
said, "My ball bounces better than yours." Nena replied, "I'd like to
see you prove that." What should Maria do?
a. Drop both balls from the same height and see which bounces
higher.
b. Throw both balls against a wall and see how far each ball
bounces off the wall.
c. Drop the two balls from different heights and see which bounces
higher.
d. Throw the balls down against the floor and see how high they
bounce.

24. 144. Why are two holes often punched in a can of juice before
pouring it?
a. to let the juice pour out of the can more slowly
b. to let the air go into one hole while the juice pours out of the
other
c. to let the air get into the can before the juice is poured
d. to let the juice pour out of the can more quietly
145. When pumping air into a ball using a hand pump, you will notice
that it is easier to pump the air in the beginning and harder at the
end. Why?
a. Air in the ball pushes against the pump.
b. Air starts to leak out of the pump.
c. The pump gets too hot to hold.
d. The pump gets too sticky to push.
146. If you throw a stone up in the air, why does it come back to the
ground?
a. The air pushes it back. c. The earth pulls it back.
b. The earth is a large magnet. d. A stone always returns to its
resting place.
147. Two cups of the same size and shape are filled with water and
alcohol respectively. They were placed near a window on a hot
sunny day. A few hours later it was observed that both the cups had
less liquid in them but that there was less alcohol left than water.
What inference can be drawn from the observation?
a. All liquids evaporate.
b. Alcohol evaporates faster than water.
c. Alcohol has a higher vapor pressure than water.
d. Water has a higher boiling point than alcohol.
148. Which of these animals live in both land and water?
a. chicken b. fish c. shrimp d. frog
149. The kinetic molecular theory states that all matter is made up of
particles that are in constant motion. Which of the following is not
true?
a. Heat increases the motion of particles.
b. Matter particles are closest in solids.
c. Matter particles have energy.
d. Matter particles in solids and liquids move at the same speed.

25. 150. Which of the following describes a positive test for the presence
of carbon in a compound?
a. The compound turns blue litmus paper red.
b. The compound turns iodine solution blue.
c. The compound leaves a black residue when burned.
d. The compound gives a popping sound when lighted.
151. A certain wild bird has webbed feet. In which of the following
places would you most likely find it?
a. a forest b. a meadow c. a lake d. a cornfield
152. Charlie shot a bird with his pellet rifle. The bird was injured and
could no longer fly. He placed the injured bird in a cage with another
bird. A few months later she had baby birds. How many babies would
probably not be able to fly?
a. none b. few c. most d. all
153. Which of the following is a source of metals like iron and
copper?
a. petrified trees b. rain water c. animal bones d. rocks
154. What gas in the air is essential for us to breathe in order to live?
a. nitrogen b. hydrogen c. oxygen d. carbon dioxide
155. What is the Sun?
a. a planet b. a comet c. a meteor d. a star
156. When a person sees something, what carries the message from
the eyes to the brain?
a. arteries b. muscles c. veins d. nerves
157. An embryo of a bird grows inside an egg for a number of days
before it hatches. Where does the baby bird get its food during this
time?
a. It makes its own food. c. It uses food stored in the egg.
b. It eats the egg shell. d. It does not need any food at such a
stage.
158. If you hang a magnet by a piece of string, the magnet always
stops with one end pointing to the north. What causes this?
a. gravity b. energy c. geomagnetism d. atmospheric pressure
159. Do you think all forests should be cleared and planted with food
crops?
a. Yes, because forests is where harmful animals live.
b. No, because forests give us lumber.

26. c. Yes, because trees take too long to bear fruits.
d. No, because forests protect watersheds.
160. Which one of these animals does not lay eggs?
a. chicken b. frog c. duck d. dog
161. Why do humans need lungs?
a. to hold the chest out c. to pump blood through the body
b. to protect against germs d. to let oxygen enter the blood
162. In which one of the following lists are the items set out from
coldest to hottest?
a. ice, boiling water, human body, fire c. human body, ice, boiling
water, fire
b. ice, human body, boiling water, fire d. fire, human body, boiling
water, ice
163. Which of the following is not a food chain?
a. grass — goat — man c. corn — chick — hawk
b. guava — worm — bird d. worm — grass — goat
164. A breakfast meal consists of milk, bread, butter, and hotdog. To
obtain a more balanced diet which one of the following should be
added to this meal?
a. a green vegetable c. coffee
b. chicken or fish d. ice cream
165. All animals need the oxygen in the air to live. Where do the fish
get most of their oxygen?
a. from air at the surface of the water c. from swallowing air bubbles
in the water
b. from air dissolved in the water d. from eating water plants
166. Garbage disposal has become a twin problem of urbanization.
Where population is high and less available land area, people simply
throw their garbage in streetcorners. Where there are no covered
garbage cans, which of the following will not be true?
a. Bad smell comes from the garbage.
b. There are flies, cockroaches and rats near the garbage.
c. Vegetables growing near the garbage are safe to eat.
d. People can become sick of cholera and typhoid.
167. Which of the following is not a type of rock?
a. loam b. metamorphic c. igneous d. sedimentary

27. 168. The male insects in a population are treated to prevent sperm
production. Would this reduce the insect population? Why?
a. No, because the females would still lay eggs.
b. No, because the insects would still mate.
c. Yes, because it would sharply decrease the reproduction rate.
d. Yes, because the males would die.
169. If 4 grams of oxygen are needed to oxidize 1 gram of copper,
what happens when 10 grams of oxygen are acted upon by 2 grams
of copper?
a. All of the copper will react with all of the oxygen.
b. Approximately 2 g of oxygen will be left over.
c. Approximately 1 g of copper will be left over.
d. Approximately 1 g. of each will be left over.
170. Two given elements combine to form a poisonous compound.
Which of the following conclusions about the properties of these two
elements can be drawn from this information?
a. Both elements are certainly poisonous.
b. One element is poisonous, the other is not.
c. Neither element is poisonous.
d. Neither element needs be poisonous.
171. What should you do if during an experiment you get a result that
does not agree with other data collected?
a. Reject your present result and use the previous data.
b. Reject all previous data collected.
c. Gather more data.
d. Make your data agree with the previous data.
172. Which of the following processes does not allow minerals
buried deep to reach the surface of the earth?
a. mining b. drilling pipes c. weathering d. volcanic eruptions
173. A distillation apparatus converts water to steam and then back
to water. It is a process of purifying water. If an apparatus distills
water at a rate of 1.5 liters per hour, how long will it take to produce
15 liters of distilled water?
a. 5 hours b. 20 hours c. 45 hours d. 10 hours
174. Where does a green plant derive the energy to carry out
photosynthesis?
a. chlorophyll b. sunlight c. carbon dioxide d. chloroplasts

28. 175. Four of these organ are situated in the abdomen of the human
body. Which one is not?
a. liver b. stomach c. heart d. kidney
176. Vinegar is a dilute solution of acetic acid. Its molecular formula
is CH3COOH. What is the total number of atoms in one molecule of
acetic acid?
a. 2 b. 3 c. 6 d. 8
177. All things being equal, a man can jump higher on the moon than
on Earth. Which of the following is the best explanation for this?
a. His mass is less when he is on the moon.
b. The force of gravity is less on the moon than on Earth.
c. His distance from the earth is greater when he is on the moon.
d. There is no air on the moon to offer resistance.
178. Under which of the following conditions does water evaporate
fastest?
a. on a hot and dry day c. on a cold and moist day
b. on a hot and moist day d. on a cold and dry day
179. Under the same atmospheric conditions, a metal pan feels
colder to touch than its wooden handle. Why?
a. Metal always has a lower temperature than plastic.
b. Metal radiates much more heat than plastic and so cools more
quickly.
c. Metal conducts the heat away from your hand better than plastic.
d. Plastic is a better heat conductor than metal.
180. Here are some possible reasons why kitchen utensils are often
made of aluminum. Which one of the reasons is wrong?
a. Aluminum is a poor conductor of heat.
b. Aluminum is malleable
c. Aluminum does not rust.
d. Aluminum does not dissolve in water.
181. Which of the following could you not pick up with a magnet?
a. a magnetic compass needle d. a sewing needle
b. a steel screw e. a brass paper fastener
182. What is the main function of the kidneys?
a. to produce antibodies to help fight diseases

29. b. to circulate the blood
c. to produce red blood cells
d. to remove waste materials from the blood
183. Three of the following are reasons gold is considered to be the
best metal for jewelry. Which one is not?
a. It has luster c. It does not corrode
b. It is malleable. d. It brings good luck.
184. If you are facing north early in the morning, where is the sun?
a. to your left c. behind you
b. to your right d. in front of you
185. A solution containing 20 g of salt in 80 g of water is placed in an
evaporating dish. If 50 g is evaporated from the solution, what is the
content of the remaining 50 g?
a. 20 g of salt and 30 g of water c. 15 g of salt and 35 g of water
b. 10 g of salt and 40 g of water d. 50 g of water only
186. The table below shows the melting point of five elements.
Element Melting point
==============================
aluminum 660 °C
------------------------------
magnesium 649 °C
------------------------------
iron 1535 °C
------------------------------
lead 327 °C
------------------------------
copper 1083 °C
------------------------------
Samples of all these elements are heated in an oven to a temperature
of 1555OC. If the temperature of the oven is then lowered, which of
the samples would solidify first?
a. aluminum b. magnesium c. iron d. lead

30. 187. In spite of the millions of years of continuous erosion and
weathering, the earth's surface was never leveled. Which of the
following is the best explanation of this observation?
a. The sea level keeps changing.
b. Movements in the earth's lithosphere continue to occur.
c. Temperature differences at the earth's surface are not large
enough.
d. Wind and water erosion are not strong enough.
188. If equal amounts of the following foods are eaten, which one
would provide the most protein for the body?
a. potatoes b. chicken c. rice d. bread
189. All of the following are ways by which sweating helps your
body. Which is most important of all?
a. It cools your body. c. It gets rid of the salt in your body.
b. It keeps your skin moist. d. It gets rid of excess water in your
body.
190. All of the following are functions of the blood in the human
body, except
a. to digest food
b. to protect against disease
c. to carry food to the cells
d. to carry waste material away from the cells
191. How are green plants important to animals?
a. Green plants consume both food and oxygen.
b. Green plants consume food and give off oxygen.
c. Green plants produce food and give off oxygen.
d. Green plants produce food and give off carbon dioxide.
192. A test tube, containing steel wool moistened with salt solution,
is sealed with a rubber stopper and weighed on a balance. After a
few days, the steel wool was completely changed to rust. The setup
is again weighed. What happens to the total mass of the setup?
a. It increases because a metal oxide is formed.
b. It remains constant because nothing is added or lost.
c. It decreases because the metal corrodes.
d. It increases because the metal expands.

31. 193. Which statement does not apply to gas molecules?
a. Gases are composed of particles called molecules.
b. Gas molecules are in constant random motion.
c. Gas molecules collide with one another in an elastic manner.
d. The average velocity of gas molecules decreases as
temperature increases.
194. What takes place as an amoeba reproduces?
a. The nucleus and the cytoplasm divide.
b. Only one cytoplasm divides.
c. Only one nucleus divides.
d. None of these.
195. Fertilization refers to the union of an egg and a sperm. Before
fertilization takes place
a. an egg swims to a sperm. c. an egg and a sperm swim toward
each other.
b. a sperm swims to an egg. d. an egg overtakes a swimming
sperm.
196. Which group of numbers shows how the cells in the egg
increase as the fertilized egg develops?
a. 1, 2, 3, 4, 5, ........ c. 1, 2, 4, 8, 16, .......
b. 1, 2, 4, 6, 8, ........ d. 1, 3, 6, 9, 12, .......
197. What may take place in the process of regeneration?
a. Lost body parts may be replaced. c. Existing cells may divide to
form new cells.
b. New individuals may be produced. d. New kinds of animals may
be produced.
198. If you found some eggs laid in water, you could be quite sure
that they were not the eggs of
a. reptiles. b. amphibians. c. birds. d. mammals
199. Which is/are true of both a mammal and a bird?
[A] Both feed their young with milk.
[B] Both start life as a single cell.
[C] Both are warm-blooded animals.
[D] Both produce eggs and sperms.
a. C only b. A and B c. C and D d. A, B and D

32. 200. Rocks are made of
a. minerals. b. soil. c. crust. d. sand
201. Which part of the earth do geologists study?
a. hydrosphere b. lithosphere c. atmosphere d. exosphere
202. Which kind of rock is formed from magma?
a. metamorphic b. igneous c. sedimentary d. conglomerate
203. Which layer is closest to the center of the earth?
a. outer core b. mantle c. crust d. asthenosphere
204. During an afternoon rainstorm, water fills a crack in a rock on
the side of a mountain. At night the temperature of the air falls below
0OC. What may happen to the rock?
a. The rock may crystallize. c. The rock may break along the crack.
b. The rock may fold. d. The rock may dissolve.
205. A seismograph is used to measure
a. the ocean at high tide. c. vibrations within the earth.
b. the hardness of minerals. d. the temperature of the core of the
earth.
206. A field contains many rocks and pebbles. Over a period of
many, many years, the rocks and pebbles will probably change to
a. lava. b. marble. c. soil. d. granite.
207. Which boy does the most work?
a. A boy pushing on a concrete wall with 200 Newtons of force.
b. A boy pulling on a lamppost with 500 Newtons of force.
c. A boy pushing a 5-kilogram chair a distance of 2 meters.
d. A boy carrying a 50-kilogram load over his shoulders.
208. Which man does the least work?
a. A man lifting a 50-kilogram bag of rice 1 meter off the floor.
b. A man pushing a 50-kilogram cart 1 meter along the floor.
c. A man dragging a 50-kilogram bag of rice 1 meter along the floor.
d. Each man does the same amount of work.
209. How much work is done when a force of 5 pounds is used to lift
a rock 2 feet?
a. 2 1/2 foot-pounds c. 3 foot-pounds

33. b. 7 foot-pounds d. 10 foot-pounds
210. With which instrument could you measure most accurately the
thickness of the cover of your science text?
a. micrometer c. yardstick
b. foot ruler d. meter stick
211. We use machines to make work easier. For example, a much
lesser effort is required when we use a ramp to roll a log to a certain
height than it does to lift it up to the same height. But why does it
take more work to do so?
a. The log is rolled a farther distance than it is lifted.
b. More force is needed to roll the log than to lift it.
c. There is friction between the log and the ramp.
d. It takes more time to roll the log than to lift it.
212. A man wants to use the smallest force he can to move a barrel
up an inclined plane into a truck. Which board should he use for the
inclined plane?
a. A board 6 feet long c. A board 10 feet long
b. A board 8 feet long d. A board 12 feet long
213. In which of these is electrical energy changed to thermal
energy?
a. voltaic cell c. solar cell
b. electric iron d. electric bell
214. A pulley is a grooved wheel with a rope passing over it. It is
used to lift heavy objects. In a single fixed pulley, the load is tied to
one end of the rope and it is lifted up by pulling down the other end
of the rope. How much effort is needed to lift a 40-kilogram load
using a single fixed pulley?
a. 20 kilograms c. 60 kilograms
b. 40 kilograms d. 80 kilograms
215. Which of the following is the best explanation why a door opens
more easily after its hinges have been oiled?
a. The oil decreases friction in the hinges.
b. The oil increases friction in the hinges.
c. The oil makes the parts of the hinges smoother.
d. The oil dissolves the rust and dust particles on the moving
surfaces of the hinges.
216. The reason for using a single fixed pulley is that
a. less work is done moving the load with the pulley than without it.

34. b. less effort is needed to move the load with the pulley than
without it.
c. the load is moved in the opposite direction as the effort.
d. no other form of simple machine can do the job except the
pulley.
217. When does photosynthesis occur in green plants?
a. Only during the day. c. At all times, day and night.
b. Only at night. d. At daytime, but only when there is sunlight.
218. Transpiration is the loss of water mainly through the stomata of
the leaves. In which plant does transpiration take place least rapidly?
a. bean plant b. corn plant c. mango tree d. cactus plant
219. When a certain part of a plant was tested to find out the kinds of
food it contained, the following results were obtained :
* Adding iodine solution to the plant part did not produce a blue-
black color.
* Rubbing the plant part on paper produced a grease spot.
* Boiling the plant part in Benedict's solution produced a brick-red
color.
From the results of these tests you can conclude that the plant part
contained
a. fat and sugar. c. only starch.
b. starch and fat. d. starch, fat and sugar.
220. The function of a flower is reproduction. From this statement,
you can conclude that
a. those kinds of plants that do not produce flowers cannot
reproduce.
b. those kinds of plants that do not produce flowers cannot
reproduce by means of seeds.
c. the main purpose of a flower on a plant is for the reproduction of
the plant.
d. a flower can carry on photosynthesis.
221. After photosynthesis, which of the following chemical changes
have taken place?
a. Oxygen and water are changed to form sugar.
b. Carbon dioxide and water are changed to form sugar.
c. Carbon dioxide and oxygen are changed to form starch.
d. Chlorophyll is changed to form starch.

35. 222. Where does the energy needed for photosynthesis come from?
a. sunlight. b. chloroplasts. c. transpiration. d. stomates.
223. The flower is the reproductive organ in flowering plants. Each
flower contains a pistil and a number of stamens. After pollination
and fertilization, a seed grows from the flower. Suppose that you
have a plant that has many flowers, and you want to prevent one of
the flowers from developing seeds, what could you do?
a. Remove one of the stamens of that flower.
b. Remove the pistil of that flower.
c. Remove the sepals of that flower.
d. You could do nothing to prevent seeds from forming.
224. The stem of a dicot plant is composed of many microscopic
tubes bundled together. These tubes are called the sylem and
phloem. A function of the xylem is
a. to carry water and minerals to the leaves.
b. to carry food made in the leaves to other parts of the plants.
c. to store food.
d. to allow gases to enter and leave the plant.
225. Fertilization must take place before a seed develops. Which
statement describes when fertilization occurs?
a. when a pollen grain falls on a pistil
b. when a pollen tube enters an ovary
c. when a sperm from a pollen tube joins with an egg cell in an
ovule
d. when an ovary becomes a fruit
226. The green color of leaves is due to chlorophyll, a chemical that
enables a plant to make food. If a plant part other than its leaves is
green, then
a. some cells in that part contain chlorophyll.
b. the color in that part cannot be due to chlorophyll.
c. that part has the same function as the leaves.
d. that part is where new leaves will sprout.
227. Sound is made by
a. moving molecules. c. energy.
b. vibrating objects. d. ears.

36. 228. Why can't you hear the sound made by a dog whistle?
a. Nothing vibrates when the whistle is blown.
b. Not enough energy is used in blowing the whistle.
c. The human ear cannot respond to sound waves with the
amplitude of those made by the whistle.
d. The human ear cannot respond to sound waves with the
frequency of those made by the whistle.
229. The frequency of a vibrating object is
a. the total number of vibrations the object makes before it stops
vibrating.
b. the number of vibrations the object makes in one second.
c. the time it takes for the object to vibrate once.
d. the time it takes for the object to stop vibrating.
230. Pitch describes the highness or lowness of a sound. In a
vibrating string, pitch determined by the tension and length of the
string. Since most materials expand when heated and contract when
cooled, how would you expect the pitch of a guitar string to change
when the guitar is brought from a very cool room into a very warm
room?
a. The pitch would become higher.
b. The pitch would become lower.
c. The pitch would remain the same.
d. The pitch would become higher in the beginning and would
slowly drop.
231. How does a guitarist raise the pitch of a guitar string?
a. by decreasing the tension on the string
b. by making the string shorter
c. by using less energy when plucking the string
d. by using more energy when strumming the guitar
232. What is the frequency of a string that vibrates 300 times in 5
seconds?
a. 60 vibrations per second c. 305 vibrations per second
b. 295 vibrations per second d. 150 vibrations per second
233. Why can we not hear the tremendous explosions occurring in
the sun?
a. Sounds cannot travel through a vacuum.
b. The frequency of the explosions is beyond human audible range.

37. c. The sun is too far, its sounds are lost in space before they reach
the earth.
d. The gravity of the sun is too great that not even sound can
escape from it.
234. As you move farther and farther away from a sound source, the
softer the sound becomes. Which reason best explains why this
happens?
a. Sound travels in all directions from a vibrating object.
b. Sound travels in air at about 1,100 feet per second.
c. Sound energy is carried in waves.
d. Sound waves lose energy as they travel away from a vibrating
object.
235. When sound waves strike a hard surface, they are reflected back
to the ear causing a repetition of the original sound, called echoes. In
a large auditorium, echoes are a nuisance and must be eliminated.
Which kind of wall material should be used in order to reduce
echoes?
a. A material that reflects most of the sound waves.
b. A material that absorbs most of the sound waves.
c. A material that can be caused to vibrate by the sound waves.
d. A material that vibrates with a different frequency as the original
sound.
236. In which kind of rock are fossils usually found?
a. sedimentary b. metamorphic c. igneous d. All of these
237. Sounds of different pitch can be made with a trombone by
changing
a. the length of the column of air in the instrument.
b. the tension of the column of air in the instrument.
c. the amount of air used in blowing into the instrument.
d. the pressure of the air used in blowing the instrument.
238. The following processes are involve in hearing a sound. Arrange
them in their proper order from the time the vibrations are passed
through the ear and heard as sound?
[A] The nerve cells are stimulated.
[B] The eardrum vibrates.
[C] The cochlea and the liquid in it vibrate.
[D] Impulses are carried to the brain by the auditory nerve.
[E] The bones of the ear vibrate.

38. a. A, B, C, E, D b. B, E, C, A, D c. B, C, E, A, D d. E, B, A, C, D
239. Sound travels about 1,100 feet per second through air. Suppose
you are standing some distance from a hill. Four (4) seconds after
you speak you hear an echo of your voice. What is your approximate
distance from the hill?
a. 550 feet b. 2,200 feet c. 1,100 feet d. 4,400 feet
240. You are standing at the end of a room across a loudspeaker at
the other end. How does the sound reach you from the loudspeaker?
a. The sound from the loudspeaker travels across the room in the
form of radio waves.
b. The molecules in the air hit by the vibrating speaker travel across
the room.
c. The energy of the vibrating speaker is transferred from molecule
to molecule in the air.
d. The vibrating speaker causes all the molecules in the air to
vibrate at the same time.
241. Toby is playing a piano. His brother across the room is listening
to the sound. What could Toby do in order to enable is brother to
hear a louder sound from the piano?
a. Use less energy to strike the keys.
b. Place a wooden box on top of the piano.
c. Move the piano closer to his brother.
d. Strike the keys more slowly.
242. One music room has a thick rug and curtain in it while another
music room has none. Suppose you turn on a radio with the same
volume in both rooms, the sound is less loud in the room with the
rug and curtain. Why?
a. The rug and curtain absorb sound.
b. The rug and curtain reflect sound.
c. The rug and curtain conduct sound.
d. The rug and curtain increase the amplitude of sound.
243. If you are frightened, your vocal cords tighten; the pitch of your
voice
a. becomes higher. b. becomes lower. c. does not change.
244. Suppose you are looking at yourself in a plain mirror that is one
meter away from you. How far behind the mirror does your image
appear to be?
a. 3 feet b. more than 3 feet c. less than 3 feet

39. 245. Different materials conduct sound at a different rate. In general
the faster sound travels through a material, the better the material
conducts sound. Suppose you have bars of the same size made of
each of the materials listed below. If you hold your ear close to one
end of each bar when it is tapped gently on the other end , through
which bar would you hear the loudest sound?
Material Speed in feet per second
==========================================
aluminum 16,700
------------------------------------------
granite 19,700
------------------------------------------
hardwood 13,500
------------------------------------------
iron 16,800
a. aluminum b. hardwood c. granite d. iron
246. Which of the following is the most recent era?
a. Paleozoic b. Cenozoic c. Mesozoic d. Precambrian
247. It is believed that the most recent group of animals to develop
were the
a. amphibians. b. reptiles. c. birds. d. mammals.
248. The strongest evidence that parts of the earth were covered with
dense plant growth millions years ago is
a. the large deposits of coal in the earth.
b. the great amount of oxygen in the air today.
c. the large number of plant-eating animals on earth today.
d. the large number of plant species on earth today.
249. While hiking at the foot of a mountain, Jose found a piece of
petrified wood. Petrification means that
a. the wood itself has become hard as stone.
b. the wood has changed to stone.
c. minerals have filled or replaced the actual wood cells.
d. the pieces of wood have become covered with a mineral coating.
250. Which group of vertebrates appeared first?
a. mammals b. amphibians c. birds d. fish

40. 251. Pieces of sedimentary rocks containing fish fossils were found
on a certain area. Yet there are strong historical and geological
evidences to prove that the said area was never covered by a lake or
sea. Which statement might best explain the occurrence of the fish
fossils?
a. The uplifting of the earth's crust by volcanoes and earthquakes
brought them to the surface.
b. Fish fossils are widespread and are found almost anywhere
whether or not lakes and seas were ever present.
c. Rocks containing the fish fossils were carried to this area by
glaciers.
d. Fishing was the main occupation of people in the area in that
era.
252. It is believed that living things first appeared in the
a. Paleozoic era. b. Cenozoic era. c. Mesozoic era. d. Precambrian
eras.
253. Paleontologists believe that the early amphibians developed
from certain
a. reptiles. b. trilobites. c. fish. d. brachiopods.
254. Coal is a fossil fuel. This means that
a. coal contains many fossils.
b. coal was formed during a time when many animals became
fossils.
c. coal itself is the fossil remains of ancient organisms.
d. coal has been used as a fuel for a very long time.
255. Two different rock layers are several miles apart. One rock layer
is sand stone and contains the fossil bones of small, primitive
dinosaurs. The other rock layer is shale and contains the fossil casts
of trilobites. Which statement about the rock layers is true?
a. The sandstone is older than the shale.
b. The shale is older than the sandstone.
c. The shale is the same age as the sandstone.
d. There is no way of telling which rock layer is older.
256. How does a modern bird differ from Archaeopteryx?
a. A modern bird has feathers. c. A modern bird has scales on its
body.
b. A modern bird has wings. d. A modern bird has no teeth.

41. 257. Birds are believed to have developed from some group of
reptiles. This means that
a. this group of reptiles changed into birds as they grew older.
b. this group of reptiles may be the ancestors of the birds.
c. over a period of many years new generations of these reptiles
became more and more birdlike.
d. this group of reptiles laid eggs from which birds hatched.
258. A paleontologist found a rock containing the footprint of an
animal. Examination of the rock revealed that the rock was formed
about 50 million years ago. From this information, what could
Tommy tell about the animal that made the footprint?
a. The animal lived much later than 50 million years ago.
b. The animal lived about 50 million years ago.
c. The age of the rock does not tell anything about the age of the
footprint.
d. The footprint was made before the rock was formed.
259. The eye is our organ of sight. We see with the eye because light
passes through the eye and forms an image which is then brought to
the brain by optic nerves. Below are listed several parts of the
human eye. How would you arrange these parts to show the order in
which light passes through the eye?
[A] pupil [B] cornea [C] retina [D] lens
a. A-B-D-C b. B-A-D-C c. C-A-D-B d. D-A-B-C
260. LDL is low density lipoprotein. It is found in saturated fats, egg
yolk, liver, coconut oil and all meats. It accumulates on artery walls
resulting in the narrowing and hardening of blood vessels. This
reduces blood flow and increases the risk of a heart attack. Which of
the following is the common name of LDL?
a. creatinin b. fat c. bile d. bad cholesterol
261. The convex lens in the human eye is different from man-made
convex lens, such as magnifying glass, in that the lens in the human
eye can
a. converge light. c. be changed in thickness.
b. refract light. d. transmit light.
262. What is the shape of a convex lens?
a. A convex lens is thicker at the edges than it is at the center.
b. A convex lens is thicker at the center than it is at the edges.
c. A convex lens is as thick at the edges as it is at the center.
d. A convex lens is thicker at one side and thinner at the opposite
side.

42. 263. When parallel beams of light pass through a concave lens, the
beams
a. converge. c. first converge and then diverge.
b. diverge. d. remain parallel.
264. Which part of the eye acts like the film in a camera?
a. retina b. lens c. iris d. pupil
265. Luminous objects differ from nonluminous objects in that
luminous objects
a. give off light. c. reflect light.
b. transmit light. d. absorb light.
266. An objects that looks black in sunlight
a. reflects all colors. c. reflects only the secondary colors.
b. absorbs all colors. d. absorbs only the secondary colors.
267. The image in a flat mirror appears to be
a. the same size as the object. c. inverted
b. larger than the object. d. taller than it is wide.
268. Which of the following statements have been given, at various
times, as scientific explanations of the way light travels?
[A] Light travels as a wave.
[B] Light does not travel, but it is everywhere at once.
[C] Light travels as a stream of particles.
[D] Light travels as packets of light called photons.
a. A and C b. C and D c. B only d. A, C and D
269. In what way are sound and light alike?
a. Both are a form of energy.
b. Both travel at the same speed.
c. Both travel in waves by transferring energy from molecule to
molecule.
d. The human eye is sensitive to all frequencies of light waves,
similarly, the human ear is sensitive to all frequencies of sound
waves.
270. Atoms of the same element always have the same number of
a. protons. b. neutrons. c. protons and neutrons. d. neutrons and
electrons.

43. 271. A community consists of
a. a group of organisms of one kind living together in the same
habitat.
b. a group of organisms of one kind living in different habitats.
c. a group of different kinds of organisms living together in the
same habitat.
d. a group of different kinds of organisms living in different habitats.
272. In which community does succession take place most rapidly?
a. An abandoned field c. A fallen log
b. A pond d. A hay infusion
273. Succession may take place in a community when
a. conditions become more favorable for some organisms than for
others.
b. the dominant organisms create conditions favorable to
themselves and unfavorable to other organisms.
c. a climax community has been established.
d. there is no dominant organism in the community.
274. A climax community does not develop in a fallen log because
a. a log is too small.
b. a log is not a good habitat for the kind of organisms that live in a
climax community.
c. the log changes in to humus before a climax community can
develop.
d. no organisms become dominant.
275. What effect(s) may a natural disaster have upon succession in a
community?
[A] It may change the course of succession in a community.
[B] It may cause a community to reach its climax stage sooner.
[C] It may interrupt the course of succession in a community.
[D] It may have little effect on succession in a community.
a. A & C b. A & D c. A only d. A, B & D
276. When do protozoans succeed bacteria in a hay infusion?
a. When bacteria create conditions unfavorable to themselves and
favorable to protozoans.
b. When protozoans create conditions unfavorable to themselves
and favorable to bacteria.

44. c. When bacteria increase in number and protozoans decrease in
number.
d. When bacteria decrease in number and protozoans increase in
number.
277. Lake Erie was once a lake with clear, cool water. During the past
twenty years, large amounts of chemicals draining into the lake from
surrounding areas have produced conditions favorable for the
growth of algae. As a result, the number of algae growing in the lake
has increased, and the lake has become green with these organisms.
As the algae die, they settle to the bottom. The lake becomes
shallower, causing the water to become warmer. If the chemicals
continue to drain into Lake Erie, what can you predict about its
future?
a. The lake will again become clear and cool after the algae destroy
themselves by overpopulation.
b. Dead plant material will collect at the bottom of the lake, making
it impossible for other plants to grow.
c. Fish that like clear, cool water will be replaced by those
preferring warmer water.
d. The increased growth of algae will cause the lake to fill in faster
than it normally would.
278. What happens when the amount of humus on the bottom of a
pond increases?
a. The increase in humus helps bring about plant succession.
b. All the plant organisms disappear.
c. Fish that build their nests in the sandy bottom are replaced by
other kinds of fish.
d. The increase in humus has no effect on the plants and animals in
the pond.
279. Which statement(s) is/are true of a community that has reached
its climax stage?
[A] All the organisms are one of a kind.
[B]The organisms are not replaced by other kinds of organisms.
[C]All the organisms are dominant.
[D]The organisms are replaced by other kinds of organisms.
a. A only b. B only c. A & C d. A, C & D
280. Which of the following is/are composed of fundamental
particles?
a. paper b. water c. oxygen d. all of these

45. 281. A magnetic compass can be used to detect an electric current
because
a. a wire carrying an electric current is surrounded by a magnetic
field.
b. a compass always points north.
c. a wire has resistance.
d. a wire carrying an electric current is surrounded by a
gravitational field.
282. Which rock has kinetic energy?
a. A rock resting at the top of a hill.
b. A rock falling from a hill.
c. A rock resting on the ground at the bottom of a hill.
d. A rock partially buried at the side of a hill..
283. Electric current is the flow of free electrons through a conductor
from a region where there is more electrons (negative) to a region
where there is less (positive). In an alternating current the free
electrons
a. move to one direction only.
b. move, then stop, and then move on in the same direction.
c. move back and forth.
d. do not move at all.
284. Atoms and ions are made up of protons, neutrons and
electrons. The difference between the two is that ions are electrically
charged atoms. Which of the following is an ion?
a. Six protons, six neutrons and six electrons.
b. Six protons, six neutrons and five electrons.
c. Six protons, five neutrons and six electrons.
d. Five protons, six neutrons and five electrons.
285. What energy transformation takes place in a light bulb when an
electric current is passing through it?
a. Light is changed to electrical energy.
b. Heat is changed to electrical energy.
c. Electrical energy is changed to light.
d. Electrical energy is changed to light and heat.
286. Circuit A has one light bulb connected to a 3-V battery. Circuit B
has two light bulbs connected in parallel to a 3-V battery. How do the
bulbs in circuit B compare in brightness with the bulb in circuit A?

46. a. The bulbs in circuits B and A would have the same brightness.
b. The bulb in circuit A would be brighter than those in circuit B.
c. The bulbs in circuit B would be brighter than that in circuit A.
d. All the three bulbs would have different brightness.
287. A polystyrene (plastic) sheet is rubbed with a piece of
newspaper. When the sheet is brought close to some small pieces of
paper resting on a desk top, the pieces of paper are attracted to the
plastic sheet. Which statement best explains why the pieces of paper
move?
a. The plastic sheet is surrounded by a magnetic field that affects
the pieces of paper.
b. Paper is always attracted to plastic.
c. Rubbing the plastic with paper generates an electric charge that
affects the pieces of paper.
d. The comb and the pieces of paper have the same charge;
therefore, they attract each other.
288. In which of the following is an electromagnet used?
a. telephone. b. light bulb. c. dry cell. d. compass.
289. Two identical bulbs are each connected to a dry cell. In circuit A,
the wire is made of copper while in circuit B the wire is made of an
unknown material. The light from the bulb in circuit A is brighter than
the light from the bulb in circuit B. What conclusion can you draw
about the wires in circuits A and B?
a. The wires in circuits A and B have the same resistance.
b. The wire in circuit A has more resistance than the wire in circuit
B.
c. The wire in circuit A has less resistance than the wire in circuit B.
d. Only the wire in circuit B has resistance.
290. A magnet is a material that attracts pieces of iron or steel. It can
also attract and repel another magnet. The power of a magnet is on
its poles. Unlike poles of magnets attract while unlike poles repel.
The three bars below are either magnets or simply iron bars.
Bar I A ================= B
Bar II C ================= D
Bar III E ================= F
If pole A attracts pole C, pole C attracts pole E, and pole A repels
pole E, which may or may not be a magnet?
a. I only b. II only c. I and II d. II and III

47. 291. George placed a piece of modeling clay on each pan of an equal
arm beam balance. The two pieces of clay are of the same size and
shape. He observed that the beam was balanced, indicating that they
have the same weight. He compressed and flattened one piece of
clay and once more observed their weights. Which of the following
observations and inferences is correct?
a. The beam will still be balanced; nothing is either added or
subtracted.
b. The beam will still be balanced; nothing can affect weight.
c. The beam will tilt down the side of the compressed clay; pressing
the molecules together increased the weight of the clay.
d. The beam will tilt up the side of the compressed clay; the clay
became smaller and therefore lighter.
292. At standard temperature and pressure, one mole of a gas
occupies a volume of 22.4 liters. When a gas sample is compressed
to half its original volume, which of the following changes?
a. number of moles c. mass of the molecules
b. average distance between molecules d. size of molecules
293. All mechanical machines have moving parts in them. Where
there are moving parts, there is friction. Why is there a need of
reducing friction in machines?
a. Friction increases the efficiency of machines.
b. Friction generates useful heat.
c. Friction contributes to the wear and tear of mechanical parts.
d. Friction increases the work being done by the machine.
294. If two substances are mixed resulting in the formation of
another substance with completely different properties, the resulting
substance
a. is definitely a mixture. c. may be a mixture or a compound.
b. is definetely a compund. d. is neither a mixture nor a compound.
295. Acids and bases can be identified by their distinct reactions
with indicators. Bromothymol blue (BTB) will change to yellow if it is
added to
a. vinegar. b. table salt. c. limewater. d. soap solution.
296. A typhoon is a tropical cyclone. This means that it originates in
the
a. cold region of the land. c. warm region of the land.
b. cold region of the ocean. d. warm region of the ocean.
297. The strongest tropical cyclone originating from the Pacific is
called a typhoon. What do you call the strongest tropical cyclone
originating from the Atlantic?

48. a. tornado b. storm c. hurricane d. super typhoon
298. Wanting to relieve himself of the tremendous bodily discomfort
due to the warmth of one hot, sunny day, Paul decided to refresh
himself with a bowl of ice cream. Why is this not such a good idea?
a. The ice cream will melt before it is consumed.
b. It is not clinically safe to drastically lower body temperatures.
c. His discomfort will worsen because his body temperature will
increase after taking the ice cream.
d. He will spend more for nothing. The ice cream will have no
soothing effect on his bodily discomfort.
299. Wind is caused by the unequal heating of the earth's surface,
which in turn causes unequal atmospheric pressure over
neighboring regions. Why does the atmosphere exert pressure?
a. Air in the atmosphere is made up of different gases. The
interaction between gases causes pressure.
b. Air has weight. Atmospheric pressure is the weight of air exerted
upon a unit area.
c. Wind is moving air. Any moving matter exerts a force.
Atmospheric pressure is the force of the wind upon a unit area.
d. Air has a temperature. Anything that has a temperature exerts a
pressure.
300. Carbon dioxide and oxygen are cycled and balanced in nature
by plants and animals. Animals take in oxygen and give off carbon
dioxide. Plants take in carbon dioxide and give off oxygen. But this
cycle is disturbed by industrialization, population, and pollution.
These are the main aggravating factors that contribute to the
increase of carbon dioxide in the air. What is the effect of too much
CO2 in the air?
a. Abrupt cooling of the atmosphere. c. Global warming of the
atmosphere.
b. Uncontrolled vegetation. d. Asphyxiation/suffocation of living
organisms.
301. Nutrients and energy are transferred in the ecosystem through
the food chain. However, toxic materials can also be transferred in
the same way. Pollution is acknowledged to be largely responsible
for cases of food chain poisoning such as the "red tide"
phenomenon. Which of the following is the specific culprit in red
tides?
a. red alga b. green alga c. diatom d. dinoflagellate
302. It's not a plant. It's not an animal. It manufactures its own food
and moves like an animal. What is it?
a. amoeba b. paracecium c. euglena d. daphnia

49. 303. Jessie, Mary and Leony have one thing in common. Their
"Islands of Langerhans" cannot produce enough insulin. What
excess material will surely be present in their blood?
a. bile b. sugar c. cholesterol d. uric acid
304. Cloning is a genetic process of creating an exact copy of an
organism. Which of the following is directly responsible for such
process?
a. ATP b. HDL c. LDL d. DNA
305. Which piece of glass is translucent?
a. A mirror in which the image of an object can be seen.
b. A windowpane through which an object can be seen clearly.
c. A frosted glass through which an object can be seen, but not
clearly.
d. A eyeglass which is tinted brown.
306. Water purification and treatment are essential processes in
making water potable. Which of the following processes removes the
offensive odor and taste of drinking water?
a. chlorination b. aeration c. sedimentation d. coagulation
307. The amount of carbon dioxide dissolved in a softdrink is what
makes one softdrink different from another softdrink. The one that
has more of the gas dissolved in the liquid is the more preferred
softdrink because of its refreshing taste. Pressure and temperature
are the two factors affecting the solubility of carbon dioxide in a
softdrink. Its solubility increases if
a. the temperature of the softdrink is increased.
b. the temperature of the softdrink is decreased.
c. the pressure inside the softdrink bottle is decreased.
d. the softdrink bottle is not sealed.
308. Acceleration is the rate of change in velocity or speed. Which of
the following is not accelerated?
a. a falling body c. a car moving in circular orbit at constant speed.
b. the second hand of a clock d. a rock rolling down a hill
309. A traditional way of making ice cream is adding salt to ice in
order to obtain a temperature lower than 00 C. What is the function of
salt in the said process?
a. Salt melts the ice much faster. c. Salt raises the melting point of
ice.
b. Salt prevents the ice from melting. d. Salt increases the freezing
point of ice.

50. 310. When you skate on ice, you are actually skating over a layer of
water. Which of the following best explains this statement?
a. Water and ice have the same molecular composition. They differ
only in state.
b. Pressure is directly proportional to melting point.
c. The friction between the skate and the ice melts the ice.
d. The skate is made of metal. Metals are good conductors of heat.
311. Two liquids, A and B, have the same volume but different
specific heat. A has a specific heat of 1.0 while B has a specific heat
of 0.6. If the two liquids are placed in similar containers under the
sun, how will their temperatures compare?
a. A will be warmer than B. c. A will be as warm as B.
b. B will be warmer than A. d. It depends on which liquid absorbs
more heat.
312. Two bodies, X and Y, are suspended from the ends of a rope
passing over a frictionless pulley. If the mass of X is greater than the
mass of Y, which of the following statements is true?
a. X moves down at constant speed. c. X and Y remains at rest.
b. X accelerates downward. d. There is no net force between X and
Y.
313. Along the North Diversion Road, Jesica and her dad were on
their way to Manila. Looking out the car window, Jesica asked her
dad how the birds could sit on the high-tension power lines without
being electrocuted with high voltage. His dad correctly explained
that:
a. The power lines do not carry high-voltage at all until they reach
the houses.
b. The birds do not touch anything directly connected to the ground.
c. The power lines are properly insulated to cover the cables
carrying the high-voltage.
d. An enzyme in the birds' claws blocks the electric shock.
314 Jerry pushes a cart with a force of 500 N and the cart moves with
a constant speed. What is the other force involved?
a. The opposite force of the cart which is also 500 N.
b. The opposite force of the cart which is a little less than 500 N.
c. The force of friction between the cart and the ground which is
less than 500 N.
d. The force of friction between the cart and the ground which is
also 500 N
315. One day, King Arthur asked Merlin why the sky is colored blue.
Merlin did not know the answer so he time-travelled into the future to

51. ask someone there. Luckily, he was able to direct the question to a
guy named MacGyver. When Merlin returned to Camelot, he
delivered the correct answer to the King. The answer was:
a. "The blue color of sunlight has a shorter wavelength and is
scattered more in the atmosphere."
b. "The sky reflects the color of the ocean which is blue in color."
c. "The color of outer space is blue when light, such as that coming
from the sun, is present."
d. "It is the will of God. Don't try to figure it out."
316. Mr. Penduco showed his Grade 6 class two aquaria of different
sizes. In one, there are 100 fish in 5 gallons of water. In the other,
there are 40 tadpoles in 2 gallons. Which of the following statements
about their population densities is correct?
a. The fish have a higher population density than the tadpoles.
b. The tadpoles have a higher population density than the fish.
c. They have the same population density.
d. Their population densities cannot be determined by the given
facts.
317. While waiting at a railroad crossing, Minnie noticed that the
whistle on the train was higher when approaching, then seemed to
drop in pitch as the train passed by. It's a good thing her boyfriend
was around to give her a correct explanation.
a. Sounds have different pitch depending on whether they enter our
right or left ear first.
b. The pitch remains the same. The illusion is created by the noise
of the locomotive.
c. An effect known as "Murphy's Law" changes the pitch of sound
with accordance to the distance of the source.
d. Sound waves from an incoming train are pressed together and
thus making them sound higher.
318. Jeremy and Jonathan are hanging from each end of a rope
passing over a frictionless pulley. If Jonathan is moving downwards
at constant speed, compare their weights.
a. Jonathan weighs more than Jeremy.
b. Jeremy weighs more than Jonathan.
c. Jonathan is as heavy as Jeremy.
d. Their weights cannot be compared based on the given
conditions.
319. Ryan learned that rockets can propel themselves through outer
space where there is no air to push against. So he consulted his
astronaut cousin, Lennart, regarding the mystery. Lennart gave Ryan
the correct explanation:

52. a. "What speeds a rocket on its way is the forward kick of the
gases, which is opposite to the kick that sends the gases
backward."
b. "Space may be vaccuum but contains solar winds from stars like
the Sun. This allows heavenly bodies, including rockets, to move
freely in space."
c. "Gravity can be harnessed. A rocket can therefore use this
harnessed force to propel itself."
d. "The information is wrong. Rockets cannot propel them-selves in
vacuum. That's why I'm not allowed to go to outer space without
proper training."
320. Jun, Rodel and Daren were playing basketball in the open court
when a thunderstorm struck. They all hurried into the car because
they knew that
a. lightning is likely to avoid striking at steel bodies like
automobiles.
b. the car is effectively insulated from the rubber tires in the car's
wheels.
c. moving targets, like fast cars, are less likely to get hit by
lightning.
d. the car's steel body leads electrical charge away from the people
inside.
321. Rey's supervisor at a fruit company asked him to sort the larger
calamansi from the smaller ones. Rey experimented by gently
shaking a box of the fruits. He discovered that the larger fruits would
a. rise to the top. c. gather in between.
b. sink to the bottom. d. stay where they are.
322. In the news, Ernie Baron predicted rain and high winds. So
Mariz glanced at her barometer and noticed it rising. Most likely, this
meant that
a. good weather was on the way. "Even PAGASA makes
mistakes."
b. the news was right. Bad weather was coming.
c. it's getting warm. A barometer is an instrument used to measure
atmospheric temperature.
d. it is impossible to predict the weather using a barometer.
323. Two suspects were being chased by the police for robbing a
bank. Driving fast, they noticed that their car tilted everytime they
turn along a curved road. Which of the following best explains their
observation?
a. Centripetal force tends to make a moving car go in a curve
perpendicular to its circular path.

53. b. Centrifugal force tends to make a moving car go in a straight line
tangent to its circular path.
c. In a curved road, vehicles must slow down. Otherwise, they will
experience this force as punishment.
d. There is no explanation yet. It is still a mystery that scientists are
unable to explain why.
324. Two bodies were dropped simultaneously from the same height
and fell to the ground at the same time. The two bodies must have
the same
a. mass. b. weight c. volume. d. density.
325. Jenny placed several mothballs in her closet to get rid of the
insects. After several days, she discovered that the mothballs were
reduced in size. What could be the best inference for her
observation?
a. The insects were nibbling on the mothballs.
b. Clothes attract the molecules of mothballs.
c. A mothball consists of various layers which become invisible
each day.
d. A mothball is made of a material that sublimes.
326. Aris and Leo saw an apparatus in the science fair which
consisted of an air-free chamber with a feather and a stone elevated
inside about to be dropped at exactly the same time. Aris argued that
the stone would hit the ground first. Leo insisted that they would fall
at exactly the same time so he pushed a button that would drop the
objects. What do you think happened?
a. Nothing. Objects do not fall in vaccuum.
b. Aris was right. The stone hit the ground first.
c. Leo was right. The objects landed at the same time.
d. Aris and Leo were both wrong. The feather hit the ground first.
327. Joey was watching his favorite TV show-- Beakman's World. Mr
Beakman pressed a plastic sheet on the table and then quickly lifted
it up. Then he placed the plastic over tiny bits of paper and they were
attracted to the plastic. Mr. Beakman explained what may happen
when two bodies are brought into intimate contact such as rubbing,
pressing, etc. Which of the following is the correct explanation?
a. One body becomes electrically charged.
b. Both bodies become electrically charged.
c. Only the insulator becomes electrically charged.
d. Nothing will happen.
328. Because of the Coriolis force, wind in the northern hemisphere
is deflected

54. a. to the east. c. to the right.
b. to the west. d. to the left.
329. Green plants are called producers because they can produce
their own food through photosynthesis. Which of the following
materials combine in photosynthesis to produce sugar?
[A] carbon dioxide [B] oxygen [C] water [D] chlorophyll.
a. A and B c. A, B and C
b. A and C d. A, C and D
330. When two materials are rubbed together, some of the loosely
held electrons of one material transfer to the other. The material that
loses electrons becomes
a. positively charged. c. alternately charged.
b. negatively charged. d. electrically neutral.
331. Why are tall buildings and poles the most probable targets of
lightnings?
a. These structures are electrically charged.
b. They have the same charge as the lightning.
c. Their charge is opposite to that of the lightning.
d. They are the nearest conductor to the charged cloud.
332. Before going to school one morning, Johnny noticed two ants.
One was trying to move a grain of corn but without any luck. The
other was carrying and moving a grain of rice. So he asked his
father: "Dad, which of the two ants is doing more work?" His dad
answered: "Kiddo, you have to figure that out for yourself. All that I
can say is, in order to do work
a. force must be applied through a distance.
b. force must be exerted through a machine.
c. energy must be spent.
d. energy must be transformed.
333. Having been clarified about the real nature of work, Johnny
inferred from then above observations that
a. the ant trying to move the corn was doing more work.
b. the ant carrying and moving the rice was doing more work.
c. both ants are doing as much work.
d. only the ant carrying and moving the rice was doing work.
334. All of the following can generate electric current except
a. voltaic cell. c. steam turbine.