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Majorship LET Reviewer

LET Reviewer for Biological Science
LET Reviewer for Biological Science

1. Which of the following statements is definitely true about the nature of science?
A. Science will help make the world a better place to live in.
B. Science can always uncover the truth in the realm of nature.
C. Scientific work requires a dedication that excludes the lives of people in other fields of work.
D. Theories in science can be disproved by testing: a well established theory can be demolished with a single observation.

2. Which of the following processes is best associated with technology than with science?
A. designing for a need
B. uncovering natural phenomena
C. discovering the nature of matter
D. constructing concepts, principles and laws

3. Which of the following statements best describes the connection between science and technology?
A. Scientist use the laws and principles discovered by technologists.
B. Technology is the part of science that deals with mechanical problems.
C. Technology involves the practical applications of scientific knowledge.
D. Science depends on technology for ideas and the organization of experimental work.

4. Which of the following is a technological concept rather than a scientific concept?
A. Tungsten has a high melting point.
B. Metals are good conductors of heat.
C. Resistance is inversely proportional to current.
D. Fluorescent lamps are improved through methods of manufacturing.

5. You want to add exactly 35.00 g of salt to a solution. What instrument must you use to measure this amount?
A. beaker
B. thermometer
C. graduated cylinder
D. triple beam balance

6. Young people stand straight. Very old ones usually stoop. Why?
A. Sedentary lives of the old.
B. Habit of stooping developed in the old.
C. Greater gravitational pull on the old than on the young.
D. Bones of the old have become weak and soft and their joints become loose.

7. Why is it not quite possible for viruses to live and multiply in the outer layers of our skin?
A. The outer layer of the skin has dead cells only.
B. The outer layer of the skin has oil which is harmful to viruses.
C. The outer layer of the skin has a lower temperature unsuitable for viruses.

D. The outer layer of the skin has salt from perspiration which is harmful to viruses
8. Alcohol thermometer works on the principle that
A. Volume usually increases with pressure.
B. Temperature usually increases with density.
C. Volume usually increases with temperature.
D. Temperature usually increases with pressure.

9. Which of the following is an important factor in explaining why seasons occur?
A. Earth's axis is tilted.
B. The sun's axis is tilted.
C. Earth rotates on its axis.
D. The sun rotates on its axis.

10. To preserve the fertility of the soil, farmer should employ the following except
A. strip cropping
B. continuous farming
C. terracing
D. contour farming

11. How can the presence of a person afflicted with HIV and/or AIDS be handled?
A. Discreetly reporting the case to health authorities.
B. Conducting home forum to discuss the identification of AIDS cases.
C. Avoid and discourage patronage of places frequented by these persons.
D. Discourage the establishment of recreation centers like cabarets and discos.

12. The following describe chemical change except
A. A chemical change takes place when a solid is changed to liquid then changed to gas
B. For a chemical change to take place, heat, light, or electricity is either needed or given off.
C. Some examples of chemical change are souring of milk, ripening of fruit, and digestion of food.
D. In a chemical change, a new substance is formed, with chemical properties that are different from, the original substance.

13. Where do we trace the El Nino phenomenon?
A. rising ocean levels
B. very severe earthquakes
C. annual changes in seasons
D. thinning or depletion of the ozone layer

14. Why does the greenhouse effect result to warmer temperature near the earth's surface?
A. clouds trap infrared radiation
B. soil absorbs incoming radiation
C. ozone traps ultraviolet radiation
D. carbon dioxide traps infrared radiation

15. Why do people feel warmer just before it rains?
A. Heat released by the condensation of water vapor.
B. The clouds prevent heat from escaping the earth.
C. The increased relative humidity makes them feel warmer.
D. The warming is due to the heat absorbed by the evaporation of water.

16. A good method to prevent soil from being eroded from a hill is to
A. irrigate the area
B. plow the hill regularly
C. plant only ion alternate layers
D. plant the hill with grass or tree

17. The possible interconnected feeding relationships among organisms in an ecosystem are termed
A. Food pyramid
B. Food web
C. Food chain
D. Food groups

18. Two beakers contain boiling water. Beaker A has a volume of 150 mL while beaker B has a volume of 600 mL. Which of the following statements is true?
A. Both beakers are at equal temperatures.
B. Both beakers have the same thermal energy.
C. Beaker A has more thermal energy than beaker B.
D. Beaker A has a higher temperature than beaker B.

19. On the ground, Francis weighs 500n. Aboard flying at an elevation of 1500 m, what would his mass be?
A. 5 kg
B. 50 kg
C. 100 kg
D. 150 kg

20. How will you classify the statement, “The earth's outer core is a liquid.”?
A. a law
B. a theory
C. an inference
D. an observation

21. To save fuel it is advisable to keep your pot tightly closed while cooking. This prevents
A. escape of nutrients
B. escape of steam, thus built up pressure
C. escape of substances which tenderize the food.
D. escape of vapor which increases the boiling point.

22. Not all organisms are harmful. Which of these is done by yeast?
A. encourage disease food
B. cause Yakult to be milky
C. cause milk to become cheese
D. promotes the rising of bread for baking

23. Which of the following organisms is used to convert milk to cheese?
A. bacteria
B. protozoa
C. viruses
D. algae

24. Why do mountain climbers use oxygen equipment at the top of high mountains?
A. There is a hole in the ozone layer.
B. There is less oxygen in the air at great heights.
C. There is less nitrogen in the air at great heights.
D. There is no air on top of very high mountains.

25. War experts use energy in its discovery of nuclear bombs. When energy is released from a nuclear fission, what occurs?
A. Atoms are split into fragments.
B. Energy is released from fission.
C. Decrease in mass nuclear bombs.
D. The energy possessed is used for bombing nations

26. Which of the following alternative sources of energy could result to acid rain?
A. solar
B. biogas
C. geothermal
D. nuclear energy

27. Which of the following is predicted to be the result of global warming?
A. rising ocean level
B. thinning of ozone layer
C. more severe earthquakes
D. larger volcanic eruptions

28. Billy is one student who tries his best to submit laboratory reports, projects, and other requirements on time. Which of the following scientific attitudes does Billy possess?
A. patience
B. responsibility
C. open-mindedness
D. honesty

29. A manager of a textile company said it is too expensive to treat liquid wastes so he suggested digging hole near the factory where the wastes can be stored. Is this environmentally safe?
A. No, the liquid can be recycled.
B. No, the liquid waste will seep to the ground water.
C. Yes, the liquid wastes will be less hazardous with time.
D. Yes, the liquid will pass through layers of soil and becomes clean.

30. The air in Metro Manila is now heavily polluted with carbon dioxide and lead dust from the motor vehicles, factories, and restaurants. As a citizen, you will minimize pollution by following all the following practices except
A. Bury garbage rather than burning it.
B. Burning garbage in your own backyard.
C. Participate actively in government's tree planting project.
D. Help disseminate information regarding the advantages of using anti-pollution devices for motor vehicles

31. Insecticides are used to control insect populations so that they do not destroy crops. However, over time, a new insecticide has to be developed as they become less effective in killing the insects. Why?
A. Insecticides build up in the soil.
B. Insecticides are concentrated at the bottom of the food chain.
C. Surviving insects pass their resistance to insecticides to their offsprings.
D. Surviving insects have learned to include insecticides as a food source.

32. Why do fishermen catch more fish during the new moon than during the full moon?
A. Fishes look for mates during the new moon
B. Fishes are attracted to the light from the fishing boat
C. Fishes go near the water surface during new moon because the water is warmer.
D. Fishes are more active during new moon because the salt content of water is just right.

33. In one of his investigations, Alexander Fleming noticed that bacteria growing on agar did not grow next to a mold that was growing on the same plate. He wrote in his report,”The mold may be producing a substance that kills bacteria.” The statement is best described as
A. a conclusion
B. a hypothesis
C. an observation
D. a generalization

34. Which of the following is the primary reason why scientists repeat measurements they take during experiments?
A. To list all the results in a table
B. To estimate experimental error
C. To check if the equipment is working
D. To change the experimental conditions.

35. When scientists investigate, it is said that they follow the scientific method. How will you logically arranged the essential steps in the scientific method?
1. make a hypothesis
2. recognize the problem
3. formulate the simplest generalization
4. perform experiments to test the prediction
5. predict the consequences of the hypothesis

A. 1, 4, 2, 3, 5
B. 2, 1, 5, 4, 3
C. 2, 5, 1, 3, 4
D. 3, 2, 1, 4, 5

36. Which of the following factors contribute to “greenhouse effect”?
A. destruction of the forests
B. use of carbon dioxide by land plants
C. depletion of minerals in the soil by overfarming
D. use of solar glass panels to capture radiant energy

37. All interacting units of matter tend to move toward a state in which energy content is a minimum, and the energy distribution is most random. In the process of attaining this state, energy matter and energy-matter transformations occur. This scheme is governed by all of the following concepts except
A. conservation
B. equilibrium
C. homeostasis
D. isostacy

38. Matter exists in the form of units which can be classified in hierarchies or organizational levels. Which of the following units show a correct hierarchical organization?
A. atom – molecule – element – compound – mixture
B. cell – tissue – organ – system – organism
C. solids – liquids – gases – plasma
D. protons – neutrons – electrons – ions

39. Which of the following statements is not true of energy in the biosphere?
A. Energy flows a one – way path.
B. Energy is conserved in the biosphere.
C. Energy follows a cycle through the web of life.
D. Energy leaves the living system in the form of heat.

40. Electrical energy is used to power a light bulb. How does the amount of electrical energy used to compare to the amount of light energy produced?
A. less than the amount of light energy produced.
B. more than the amount of light energy produced.
C. the same as the amount of light energy produced
D. depends on the wattage produced by the light bulb

41. The following statements are ideas about the environment. Which one is false?
A. Clear water is clean water.
B. Plants help clean the air of harmful gases.
C. It takes millions of years for crude oil to form.
D. Fire can sometimes start by itself in a big pile of decaying garbages.

42. Ultrasound is often used by medical workers to obtain features of internal body parts. Infrasound on the other hand is commonly used in:
A. monitoring conditions in pregnant women
B. detecting harmful living tissues inside the body
C. seismographic surveying of structures below the earth's surface
D. providing moving pictures of tidal waves and earthquakes

43. A 12 cm red hot steel bar is placed into a pan of boiling water. Which statement correctly explains the resulting heat transfer?
A. Heat flow out of the kettle to the cooler surrounding air.
B. Heat flow from the water to the steel bar because boiling water has more thermal energy.
C. Heat flows from the water to the steel bar since the water molecules have higher average kinetic energy.
D. Heat flows from the water to the steel bar since the steel bar is at a higher temperature.

44. Which of the following acid groups is found in vinegar?
A. nitric acid
B. acetic acid
C. formic acid
D. ascorbic acid

45. Which of the following forms of energy travels through empty space?
A. chemical energy
B. radiant energy
C. sound energy
D. all of them

46. Why do we see the sun rise in the east and set of the west?
A. the earth rotates from west to east
B. the earth revolves counterclockwise
C. the earth rotates from west to east
D. the sun rotates in a clockwise manner

47. All of the following are physical properties except
A. sugar dissolves in water
B. water evaporates from an open container
C. moth balls sublime at room temperature
D. butter turns rancid when left unrefrigerated

48. Colloids maybe dispersed in a gas, liquid, or solid. Which of the following colloidal systems show a liquid dispersed in a gas medium?
A. clouds
B. smoke
C. paint
D. beaten egg white

49. Which blood transfusion would agglutinate blood?
A. A donor ---> A recipient
B. A donor ---> O recipient
C. A donor ---> AB recipient
D. O donor ---> AB recipient

50. All of the following compose the male reproductive organ of a flowering plant except
A. anther
B. pollen grain
C. Stigma
D. stamen

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