SCIENCE SIMULATED EXAM

Teacher Pen Roces

PSHS Review 2011

DIRECTIONS: Read each question carefully. Choose the letter of the best answer, if the answer is not among the choices answer E.

1. More aquatic plants can be found near the surface rather than at the bottom of the deep pond. What is the main reason for this?

a. They can take in oxygen from the air above the water.b. They can obtain light energy for photosynthesis.c. They can provide shade and shelter for the animals in the pond.d. They can get sufficient nutrient to grow well.

2. If a Mack truck and a Volkswagen have a head on collision, which vehicle will experience the greater impact force?

a. the Mack truckb. the Volkswagenc. both the samed. it depends on other factors

*the volkswagen having the lesser mass will experience the greater impact because of F=ma

*even aquatic plants need sunlight for photosynthesis

3. Which of the following statements about the sound is/are true?

A. Sound is a kind of matter.B. Sound can be used to communicate.C. Sound can be converted to another form of

energy.

a. B only b. A and C only c. B and C only d. A, B and C

4. Look at the diagram below.Which one of the following should be placed between A

and B so that the light will light up?a. a glass rodb. a plastic spoon Ac. a piece of steel d. a piece of rubber B

*sound doesn’t have mass and volume thus it is not matter

*only the steel is a conductor all others are insulators

5. When a piece of wood is burned it turns in to charcoal, this type is an example of a _____________________a. Mutation b. Chemical Change c. Transformation d. Physical Change

*For numbers 6 and 7, refer to the following information:The half-life of a radioactive substance is the time

required for the half of the amount of the substance to change the other substances. The half-life of radium-226 is 1600 years.6. How long will it take for a 2.0 g sample of radium-226 to become 0.5 gram of the same substance?a. 1 600 years b. 2 400 years c. 3 200 years d. 4 000 years7. After 4 800 years, how many grams of the element would be left?a. 1.0 gram b. 0.5 gram c. 0.25 gram d. 0.125 gram

*burning produces a new kind of substance

*it takes two half lives for the substance to reach 0.5g, 2,0x1/2x1/2=0.5g ; 1600+1600=3200

*4800/1600=3half-lives; 2.0x1/2x1/2x1/2=0.25g

*For numbers 8 and 9, study the table below then answer the questions.

DATE SUNRISE SUNSETA. March 21 6:00 am 6:07 pmB. June 12 5:28 am 6:28 pmC. September 23 5:45 am 5:53 pmD. December 22 6:18 am 5:35 pm

8. On which of the four dates is daytime longest?a. March 21 b. June 12c. Sep 23 d. December 22

9. On which of the four dates is night time longest?a. March 21 b. June 12c. Sep 23 d. December 22

*daytime was 13hrs

*sunset was earliest thus night time is longest

10. Which particle in an atom is the lightest and is in constant motion?

a. Proton c. Neutronb. Electron d. Polytron

11. What determines the atomic number of an element?a. # of Protons b. # of Electronc. # of Neutron d. # of Poytron

12. What determines the atomic mass of an element?a. # 0f Protons & Electrons b. # of Electron & Neutronc. # of Neutron & Polytron d. # of Proton & Neutron

13. Which diagram below will you think the seesaw is in table and balance state?a. b.

c. d.

14. The green pigment present in leaves of the leaves of plants play an important role in photosynthesis. What is implied by the fact that the pigment is green?

a. The leaves absorb green lightb. The leaves reflect all kinds of light except green lightc. The leaves absorb all kinds of light except green lightd. none of the above

*to balance out the heavier weight the smaller ball has to be move farther away from the fulcrum

*the reflected light determines the color of an object

15. A rainbow is an arch of light that exhibits the colors of a spectrum and usually appears after the rain. Why is this so?a. Raindrops serve as prisms that refract lightb. Raindrops block white light and reflect each of its componentc. Rainbow is the product of all reflections of different particles in the skyd. Acid rain reacts with the particles in the sky, creating the rainbow

16. Visible light, being a form of electromagnetic wave, possesses wave-like properties such as wavelength. What visible light has the longest wavelength?a. red b. infrared c. ultraviolet d. violet

17. Sound and light travel as waves. Which of them can travel in a vacuum?a. light only b. both sound and light c. sound onlyd. neither sound nor light

*a prism breaks down white light into ROYGBIV

*although infrared has the longest wavelength the question is asking for the a visible light therefore red is the answer

*sound needs a medium to travel unlike light

18. What characteristics do mammals have?a. They lay eggsb. They have are born alivec. They breathe through their skind. Their bodies are made up of 3 parts

19. What is the function of the large intestine in our digestive system?a. It digests the food.b. It passes the digested food to the blood.c. It passes the digested food out of the body.d. It takes away water from the undigested food.

*although there are exceptions to this b is representative of majority of mammals

*digestion ends in the small intestines, absorption of water takes place here

20. Carlo wants to carry out an experiment to find how light affects the amount of oxygen in an aquarium.

A B C D- clear glass - fish - clear glass - fish- fish - glass - fish - glass- water coated with - water plants coated with

black paint black paint- water plants

Of the 4 set-ups A, B, C and D shown above, which two should he use to ensure a fair test?

a. A ad B b. B and C c. A and D d. C and D

21. Which of the following is not mismatched?a. Mesosphere: Weather Changesb. Stratosphere: Ozone Layerc. Thermosphere: Commercial Planesd. Troposphere: Radiowaves

*look for set-ups with almost identical variables except for a few differences such as in C and D

22. Alana wants to test the effect of pesticides on plants. What order of scientific method must she use?

a. Theory-Experimentation-Conclusionb. Inference-Experimentation-Conclusionc. Hypothesis-Experimentation-Conclusion d. Conclusion-Experimentation-Hypothesis

23. Which of the following has a correct relationship?A. Evaporation: solid to gas B. Condensation: gas to liquidC. Sublimation: gas to plasma D. Deposition: gas to solida. B & D b. A & C c. C & D d. B only

24. Light travels at the rate of 300 000 km per second, and sound travels at the rate of 400 meters per second. If there is a time difference of 6 seconds between the time you see the lightning and hear the thunder, about how many meters away is the lightning?a. 4 500 m b. 2 400 m c. 1 600 m d. 550 m

*only B and D are true

*(400m/second)x(6seconds)= 2400m

25. A comb is rubbed in a plastic cover and produced a static charge and is placed near the human hair. The comb is found to be negatively charged. The charge of the hair will be _________a. neutral b. zero c. Negative d. Positive

26. S N Magnet A Magnet B

S NN SMagnet C

When Magnet A is pushed towards the right, what will happen?a. Magnet B will be attracted to Magnet A, Magnet C will be repelledb. Magnet B will be repelled and moves vertically upward.c. Magnet B will be attracted to both Magnet A and Magnet C.d. Magnet B will be repelled and becomes attracted to Magnet C.

*unlike charges attract

*unlike poles attract while like poles repel

27. The sun’s production of energy is through a nuclear reaction. Which of the following is this?

a. fusion of helium atomsb. fission reaction og uraniumc. fission of helium atoms to form hydrogend. fusion of hydrogen atoms to form helium

28. The greenhouse effect results in warmer temperatures near the surface. Why is this so?

a. carbon dioxide molecules do not permit the radiation leaveb. carbon dioxide and water vapor both trap infrared radiationc. clouds trap infrared radiation near the surfaced. some of the energy is reradiated back toward the surface

*the fusion of hydrogen atoms to form helium produces heat, light and radiation energy

*this is the reason why Venus is the hottest planet

29. Why is the mitochondria called the “powerhouse” of the cell?a. it provides the cell with carbohydratesb. it is responsible for ATP to be broken downc. it is where ATP is synthesizedd. it has a plug that you can place in an electrical socket.

30. Which of the following is/are needed for cellular respiration?A. glucose B. sunlight C. water D. oxygena. A & D b. A, B & Cc. D only d. A only

31. Which of the following is/are by-products of photosynthesis?A. oxygen B. water C. starch D. carbon dioxidea. A & D b. C only c. A only d. A & B

*synthesize means formed, starch + oxygen → ATP + carbon dioxide↑ + water↑

*refer to 29 starch and oxygen are the only substances needed for respiration

*by-product means it is no longer needed thus given off, Carbon dioxide + water → starch + oxygen↑

32. Mary puts a balsam plant into a beaker of water in which some blue ink has been added. A few hours later, she observes that the flowers turn from white to blue. What does the experiment show?

a. The stem joins the roots to the rest of the plant.b. The stem carries water from the roots to the rest of the

plant.c. Water absorbed by the plant only through its roots.d. Water is lost to the surroundings from every part of the

plants.

33. Which of the following objects gives out light of its own?a. Star b. Moon c. Battery d. Diamond

*the experiment shows that the ink travel from the root to the flower through the stem

*only the star produces its own light

34. Six objects are classified into two groups as shown in the table.GROUP A Paper cup: Balloon : CottonGROUP B Glass : Sewing needle : Diamond

The objects are grouped according to -----a. how hard they are b. what materials they are made ofc. whether they are water proof d. whether they can be recycled

35. In a pond, there are very tiny plants which are too small to be seen by our eyes. They are important to the aquatic animals in the pond because they -----a. protect them.b. are source of food.c. help to keep the water warm.d. breakdown dead organisms into simple substances.

36. The process that produces sugar and oxygen in plants is -----a. Photosynthesis b. Respirationc. Absorption d. Digestion

*group A are soft materials, while group B are hard

*they are producers in the aquatic food web

37. If you were on the moon, your -----a. weight and mass would be less b. weight and mass would be morec. weight would be lessd. mass would be less

*the acceleration due to gravity in the moon is only 1/6 that of the earth’s, thus weight is less, mass is constant

A shoe box was divided into two rooms by a piece of cardboard across the center of the box. Ten flies were placed in each room of the shoe box. A small hole was made in the cardboard to allow the flies to move back and forth between the two rooms. One room of the box is lighted and the other was dark. The flies in the lighted side of the box were counted at different air temperatures. The count were as follows:

Air temperature (degrees C) No. of Flies in the light side of the box5 010 015 220 1725 2030 20

38. The hypothesis being tested was that -----a. flies don’t like being crowded in a boxb. flies move from dark to the lightc. flies don’t like darkd. the reaction of flies to light depends on the temperature

*the temperature’s effect on the flies’ behavior is being tested

*For questions 39-42, also use the key below as your choices.

a. The statement is true, and the experiment gives direct evidence for it.

b. The statement is probably true but is not tested in the experiment.

c. The statement is false, and the experiment gives direct evidence of this.

d. There is nothing in the experiment that gives any information about this.

39. Between 15 C and 20 C, the number of flies in the light side of the box increase markedly.

40. The flies in the dark side of the box were asleep.

41. Temperature is not a factor in the response of this kind of fly to light.

42. Each of the flies contains eight chromosomes.

*15 more were added to the number of flies

*this was not observed in the experiment

*as temperature increased more floes were observed

*this was not observed in the experiment

43. Which of the following statements about the human circulatory system in NOT true?a. All arteries conduct blood away from the heart while all veins

conduct blood towards the heartb. All arteries conduct oxygenated blood while all veins conduct

deoxygenated blood. c. All arteries have relatively thicker walls than veinsd. All arteries are connected to veins by capillariese. NONE OF THE ABOVE (all statements are true)

44. Jane figured in a car accident. When she woke up in the hospital she lost her ability to talk. What part of the nervous system was affected?

a. cerebrum b. cerebellumc. spinal cord d. brain stem

*cerebrum is the part of the brain that controls thought, memory and the senses

45. If you eat pechay now, you will defecate pechay later. Why is this so?

A. the human digestive system cannot digest celluloseB. vegetables cannot be digested at all by consumersC. vegetables have ways of eluding digestionD. pechay is not good for humansa. A only b. B & Cc. B, C & D d. A, B & C

46. Which of the following is the correct sequence of sites that oxygen will pass through when it is inhaled?

a. nostrils→larynx→pharynx→lungsb. nasal cavity→pharynx→larynx→glottisc. external nares→pharynx→trachea→alveolid. bronchi→larynx→pharynx→nasal cavity

*only ruminants are capable of digesting the cell wall o f plants

*nares is more commonly referred to as nostrils

47. The longest day in the northern hemisphere falls on a solstice. What is this day?

a. June 21 b. June 12c. December 21 d. March 21

48. What is the most abundant element in the universe? The presence of this element allows stars to produce their own light.

a. carbon b. hydrogenc. nitrogen d. oxygen

49. What will happen to two balls of different masses dropped from the same height at the same time, if air resistance is neglected?

a. they will cover the same distance for the same amount of time

b. they will have equal time of flightc. they will have the same final velocitiesd. all of the above

*the longest day occurs during Summer solstice in the northern hemisphere

*it is necessary for the star to continue to produce light, heat and radiation energy

*only accelaration of gravity is at work and is the same for both balls

50. A book is placed in front of the driver on the dashboard of a car. The car is moving uniformly forward. Suddenly, the car accelerates. What will happen to the book?

a. It will be thrown toward the driverb. It will be thrown forward toward the windshieldc. It will be thrown sidewaysd. It will remain where it is

*because of inertia the book will resist the change in speed