PAX Science NLN Exams collection 2023 (Answered) latest

PAX Science NLN Exams collection 2023 (Answered) latest 1. A person blows his breath into a straw that is placed in limewater. The limewater becomes cloudy because the person's breath contains A.) carbon dioxide. B.) hydrogen. C.) oxygen. D.) nitrogen. 2. A physician measures the pulse and blood pressure (BP) of all patients on a routine basis. Which of these measurements show the normal BP values for a resting adult patient? A.) 125/95 mm Hg B.) 120/80 mm Hg C.) 100/80 mm Hg D.) 72/120 mm Hg 3. A woman suddenly chokes on a piece of food and clutches frantically at her throat. An immediate remedy is to A.) have her bend forward and tell her to cough. B.) insert a finger or a blunt object toward the back of the mouth. C.) apply quick, hard pressures successively to her abdomen, just beneath her diaphragm. D.) phone "emergency" for help. 4. An unknown gas is more dense than air, does not support combustion, and turns a limewater solution cloudy. This gas is most probably A.) ammonia. B.) methane. C.) carbon dioxide. D.) hydrogen. 5. Human testes produce A.) eggs. B.) follicle stimulating hormone. C.) growth hormone. D.) spermatozoa. 6. If a red light is passed through a dilute solution of chlorophyll solution, the spectrophotometer will detect what amount of transmittance of this light? A.) 100% B.) 50 - 75% C.) Less than 25% D.) None - answer: 7. In diagnostic testing, the electroencephalogram permits the physician to A.) examine the impulses of the specialized muscle cells of the heart. B.) examine the impulses of the nerve cells within the brain. C.) measure the pressure within the eye. D.) measure the amount of air upon exhalation. 8. To sterilize a metal probe in the office, a dentist could use a steam sterilizer. If unavailable, the next most effective method to sterilize the instrument would be A.) boiling it in water for 15 minutes. B.) dipping it into a concentrated acid solution. C.) heating it in a hot air oven at 160°C for 20 minutes. D.) washing it in soap and water. 9. In varieties of matter, the term heterogeneous may be applied to A.) elements, but not compounds. B.) compounds, but not elements. C.) compounds and elements, but not mixtures. D.) mixtures, but not elements or compounds. 10. Heat energy is absorbed in which of these phase changes? A.) Br2 (l) - Br2(s) B.) Br2 (g) -- Br2(l) C.) Br2 (l) - Br2(g) D.) Br2 (g) - Br2(s) 11. Periodontitis is an inflammatory condition of the A.) gum tissue that surrounds the neck of each tooth. B.) pulp that contains nerve cells and blood vessels of the tooth. C.) dentin that surrounds the soft part of a tooth. D.) enamel that provides a hard surface for chewing 12. The atoms of an element with seven valence electrons are most probably classified as A.) metals. B.) nonmetals. C.) metalloids. D.) noble gases 13. The inherited factors that are transmitted in an organism from generation to generation are called its A.) homozygote. B.) heterozygote. C.) genotype. D.) phenotype. 14. The process of nuclear cell division in the cell reproduction of plants differs from mammals. A major difference is that A.) homologous chromosomes are paired. B.) centrioles are replicated. C.) spindle fibers are missing. D.) cell plates are synthesized. 15. Unicellular organisms that have a nucleus and can swim with the aid of cilia are examples of A.) monerans. B.) plants. C.) fungi. D.) protozoans. 16. Which of these conditions is associated with smoking? A.) Esophageal varices. B.) Tonsillitis. C.) Emphysema. D.) Blindness. 17. Which of these equations best illustrates a synthesis reaction? A.) 2Na + Cl2 - 2NaCl B.) NaOH + HCl - NaCl + H2O C.) 2H2O2 - 2H2O + O2 D.) CH4 + 2O2 - CO2 + 2H2O 18. Which of these hydrocarbons is a member of the benzene family? A.) Toluene. B.) Ethyne. C.) Propanone. D.) Methanol 19. Which of these quantities is most closely associated with an object's inertia? A.) Weight. B.) Energy. C.) Power. D.) Mass. 20. Which of these sequences of anatomic organization, from the simplest level to the most complex, is the correct sequence? A.) From tissue, organ, organ system to organism. B.) From organ system, organ, tissue to organism. C.) From tissue, organ system, organ to organism. D.) From organ, organ system, tissue to organism 21. Which of these single instruments may be used to measure the current flowing through a circuit? A.) A voltmeter. B.) An ammeter. C.) A potentiometer. D.) An ohmmeter. 22. Which of these temperatures is known as Absolute Zero? A.) 0°C B.) 0 K C.) positive 273°C D.) negative 273 K 23. Which part of the human central nervous system controls voluntary movements? A.) Spinal cord. B.) Cerebellum. C.) Cerebrum. D.) Medulla. 24. Within which of these structures of the female reproductive tract is the human egg fertilized? A.) Uterus. B.) Fallopian tube. C.) Vagina. D.) Cervix. 25. You cut your finger rather deeply while slicing an apple. Which of these actions should you take first? A.) Apply a sterile adhesive bandage. B.) Press the cut surface to stop the flow of blood. C.) Swab the wound with mild antiseptic. D.) Wash the wound continuously with cold running water. 26. A lens that focuses distant light to a single point is known as a A.) converging lens. B.) diverging lens. C.) concave lens. D.) prismatic lens. - answer: converging lens. 27. A magician rapidly pulls a tablecloth from a table, leaving the dishes undisturbed. Which of these principles of physics explains this "trick"? A.) Gravitational force depends directly on mass. B.) Objects at rest tend to remain at rest. C.) Force equals mass times acceleration. D.) An object traveling at constant velocity has no net force on it. - answer: Objects at rest tend to remain at rest. 28. A quantity that has both magnitude and direction is called a(n) A.) resultant. B.) scalar. C.) vector. D.) undefined unit. - answer: vector. 29. A recently discovered species has these characteristics: amniotic eggs, a four-chambered heart, and lightweight, honeycombed bones. Which of these ADDITIONAL characteristics is likely to be present? A.) Mammary glands. B.) External fertilization. C.) Ectotherms. D.) Feathers for flying. - answer: Feathers for flying. 30. Amnesia in humans is the loss of memory. Which of these parts of the brain has been affected when someone is suffering from amnesia caused by head trauma? A.) Cerebral cortex. B.) Cerebellum. C.) Medulla oblongata. D.) Spinal cord. - answer: Cerebral cortex. 31. An example of the most complex level of organization in a frog is the A.) epithelium. B.) striated muscle. C.) respiratory system. D.) stomach. - answer: respiratory system. 32. Anaerobic respiration occurs in muscle tissue when it cannot get sufficient oxygen to function aerobically. Which of these conditions is most likely to directly result from this? A.) Cramps. B.) Necrosis. C.) Bleeding. D.) Swelling. - answer: Cramps 33. Enzymes that are involved in biochemical reactions are organic A.) colloids. B.) catalysts. C.) cathodes. D.) constants. - answer: Catalysts 34. In a study on the effect of cocaine on the brains of rats, two groups of animals were selected. Each day, Group A was injected with the drug dissolved in water, whereas Group B was injected with water alone. In such a study Group B is included as A.) an experimental group. B.) a test group. C.) an exercise group. D.) a control group. - answer: a control group. 35. In corn plants, the gene that codes for the presence of chlorophyll is sometimes missing. The resulting seedlings are albino and will not survive. This lethal gene appears in corn populations because A.) the soil nutrients will not allow the plant to produce chlorophyll. B.) the parent plants that produced the seeds carried the recessive gene for the albino trait. C.) the farmer used herbicides, which destroyed the chlorophyll in the seedlings. D.) the seeds were old and stored improperly, resulting in the lethal trait. - answer: the parent plants that produced the seeds carried the recessive gene for the albino trait 36. In the reaction of iron with water shown below, what coefficient must be placed before the iron (Fe) to balance the reaction? Fe + 4H2O ° Fe3O4 + 4H2 A.) 2 B.) 3 C.) 4 D.) 6 - answer: 3 37. A circuit contains three 3-ohm (W) resistors in series. What is the equivalent resistance of this combination? - answer: 9W 38. An example of an adaptation to prevent water loss in plants is - answer: waxy epidermis 39. At room temperature, which of these substances exists as diatomic molecules? - answer: oxygen 40. Compounds with the same type and number of atoms and the same chemical bonds but different spatial arrangements of these bonds and atoms are called - answer: structural isomers. 41. The calorie and the kilocalorie are units of - answer: energy 42. The force of gravity on an object is that object's - answer: weight 43. The light sensitive cells of the eye are called rods and cones. Which of these layers of the eye are they found in? - answer: retina 44. The meiotic division of cells leads to the production of cells that - answer: contain half the usual number of chromosomes. 45. The most probable area of study that would show the prevalence of mental illness in midManhattan is that of - answer: epidemiology 46. The normal boiling temperature for water is 100° when measured on which of these scales? - answer: celsius 47. What is the pH of a solution whose H+ ion concentration is 1 x 10-2 mole per liter? - answer: 2 48. When a column of air is vibrating at the same rate as a tuning fork, the process is referred to as - answer: resonance 49. When a population is in Hardy-Weinberg equilibrium, which of these conditions must be present? - answer: The population is isolated from other populations. 50. When three resistors of 10.0 ohms each are placed in series, the total resistance is - answer: 30.0 ohms 51. Which of these changes occurs in the kidneys when a person becomes dehydrated? - answer: The filtration rate of water remains constant and the reabsorption of water increases. 52. Which of these could be stopped by a sheet of paper? - answer: Alpha particle 53. Which of these is an example of a simple machine? - answer: lever, pulley, inclined plane 54. Which of these organisms might be found in contaminated well water? - answer: Giardia 55. Which of these processes occurs at a neuromuscular junction? - answer: Impulse transmission. 56. 1 kilogram (kg) of solid X at 10°C and 1 kg of solid Y at 10°C each absorb 5 joules of heat energy. The final temperatures of X and Y are 15°C and 20°C, respectively. Compared to X, Y must have a lower - answer: specific heat 57. A drop of dilute ammonium hydroxide (NH4OH) is placed on one side of a slide containing a large number of swimming paramecium. Under this condition, which of these behaviors of the paramecia will be observed? - answer: They will eventually all swim away from the ammonium hydroxide. 58. A physician measures the pulse and blood pressure (BP) of all patients on a routine basis. Which of these measurements show the normal BP values for a resting adult patient? - answer: 120/.80 mmHg 59. Which of these processes is responsible for the recorded production of CO2 by yeast cells from sugar solution? - answer: anaerobic respiration 60. In classical physics, light is viewed as part of the electromagnetic spectrum, traveling in the form of transverse waves. Quantum physics proposes that light is composed of quanta called - answer: photons 61. Enzymes that are involved in biochemical reactions are organic - answer: catalysts 62. How much current is drawn by a light bulb that has a resistance of 100 R with a voltage of 110 V? (V = IR) - answer: 1.1 amperes 63. Sodium will react most readily with - answer: chlorine 64. The watt is a unit of - answer: power 65. The boiling point of liquid nitrogen at one atmosphere pressure is 77 K. This temperature is equivalent to. - answer: - 196 C 66. The energy associated with an object's position is termed - answer: potential energy 67. The extension of a neuron that carries the impulse to another cell is called - answer: axon 68. What is the correct sequence in the life cycle of a moth? - answer: Egg, larva, pupa, adult. 69. When water passes from a region of greater concentration to a region of lesser concentration through a selectively permeable membrane, the process is known as - answer: osmosis 70. Which of these experiments would be an effective way to determine the distribution of touch receptors in the skin? - answer: Have a blindfolded student tell when a bristle placed lightly against the skin is felt. 71. Which of these processes is used to free contaminated water of bacteria? - answer: Passing it through charcoal. 72. Which of these structures produces sperm cells in human males? - answer: testes 73. What is a gram stain? - answer: an important technique used in the laboratory thatdistinguishes between different kinds of bacterial cell walls. 74. Reducing the use of aeresol cans has contributed to the decrease of? - answer: the destruction of the ozone layer 75. The atomic number of flourine is 9. How many electrons are contained in the second principal energy level of a flourine atom in the ground state? - answer: 7 76. The second law of thermodynamics states that with every spontaneous process, the entropy of the universe - answer: increases 77. When blood is filtered in the kidney and urine is produced, red blood cells and plasma proteins do not pass through the blood capillaries. This occurs because - answer: blood and plasma proteins are needed by the body, so they do not get filtered out into the kidney. 78. Which of these germ layers gives rise to the skin? - answer: ectoderm 79. A material that settles out of a reaction is termed a - answer: colloid 80. According to the Ideal Gas Equation (PV = nRT), if the temperature and amount of gas are kept constant, what will be the effect of an increase in pressure on the volume of a gas? - answer: As the pressure increases, the volume decreases. 81. All living cells contain cytoplasm. Cytoplasm is important because it - answer: controls what moves in and out of the cell. 82. All of these groups of land plants produce seeds EXCEPT - answer: evergreen trees, such as pines and spruces. 83. Charles Darwin's theory of evolution suggests that the reason for the various differences between species is a result of - answer: natural selection 84. In order to observe the endoplasmic reticulum in a cell, a scientist would use - answer: an electron microscope 85. Scientists have discovered that most vertebrates have cone cells in their eyes, which distinguish colors in daylight. The rods are more sensitive to light, but do not distinguish colors. If a mammal is nocturnal - answer: there are fewer cones and a greater concentration of rods to collect the minimal light for night vision. 86. The functional group present in all alcohols is the - answer: hydroxyl group 87. The scientific name of the wolf is Canis lupus. The name indicates the wolf's - answer: genus and species 88. The weight of an adult human in newtons (N) is closest to - answer: 500 N 89. When two atoms share a pair of electrons, the bond between them is called - answer: covalent 90. When a sperm and egg join to form a zygote in humans, what determines the sex of the child that is produced? - answer: sperm 91. Which of these arrangements of atoms is found in all alcohols? - answer: C-OH 92. Which of these units is associated with magnitude, but not direction? - answer: Time 93. Which aspect of a simple machine is represented by the ratio work output to work input? - answer: Actual mechanical advantage. 94. 30 students in a class carefully measure the length and width of 20 peanut shells. They also count the number and note the size of the peanuts inside. This information is recorded on various graphs showing the numbers of nuts and the different sizes. The collected evidence of the peanuts gives the students an idea of the extent of - answer: variation within a species. 95. A lens that focuses distant light to a single point is known as a - answer: converging lens. 96. During exercise, a person's respiratory rate increases due to - answer: an increase in CO2 concentration in the blood. 97. Ganglia are made up of a cluster of - answer: neurons. 98. To determine the optimum conditions for the activity of a digestive enzyme, it would be necessary to test its activity over a range of - answer: temperature, pH and substrate concentration. 99. Which of these findings suggests a serious illness from a urinalysis? - answer: Presence of glucose and protein. 100. As part of the human immune response, which of these cells are responsible for producing antibodies? - answer: lymphocytes 101. A cell which manufactures a large amount of protein for export would have an abundance of organelles called - answer: ribosomes 102. A lab technician has the choice of four different enzymes to use in an experiment that will run at 25°C. The optimal temperatures of enzymes using the Kelvin scale are: Enzyme A: 273 K, Enzyme B: 298 K, Enzyme C: 310 K, Enzyme D: 325 K. Which enzyme would be the best to use in this experiment? - answer: Enzyme B 103. If a person is fasting for 24 hours and ingests no carbohydrates, the liver will provide for the body's need by - answer: converting glycogen into glucose. 104. The physics principle that is primarily used in developing a rollercoaster ride is - answer: centripetal force 105. Whole blood of type AB can be transfused to people with which of these types of blood? - answer: AB only 106. Which of these organ systems does NOT provide for the excretion of substances? - answer: lymphatic 107. Which of these processes is illustrated by the spreading out of ammonia vapor in a closed room? - answer: Diffusion 108. Which human body system does meiosis occur in? - answer: reproductive 109. Which biochemical family do starch and glycogen belong in? - answer: carbohydrates 110. The succession of flora and fauna encountered while climbing a mountain in the northern hemisphere is similar to that found when traveling from the base of the same mountain in which of these general directions? - answer: North 111. When steel wool (mostly iron) burns, its mass increases. The best explanation of this observation is that - answer: the iron oxide formed has more mass than the iron alone. 112. The number of complete waves which pass a point in one second is known as a - answer: frequency 113. An example of an adaptation to prevent water loss in plants is - answer: waxy epidermis 114. A circuit contains three 3-ohm (W) resistors in series. What is the equivalent resistance of this combination? - answer: 9 W 115. Which of these quantities is a vector quantity? - answer: force 116. Which of these substances carries energy within cells and is produced as a result of cellular respiration - answer: ATP 117. Which of the structures contains valves to prevent blood from flowing in the wrong direction? - answer: veins 118. Which of these is an example of a simple machine? - answer: all of the above 119. When three resistors of 10.0 ohms each are placed in series, the total resistance is - answer: 30.0 ohms 120. When a drop of dilute nitric acid is added to water surrounding a hydra, the animal draws in its tentacles. The acid is acting as - answer: a stimulus 121. When a column of air is vibrating at the same rate as a tuning fork, the process is referred to as - answer: Resonance 122. Scientists have discovered that most vertebrates have cone cells in their eyes, which distinguishes colors in daylight. The rods are more sensitive to light, but do not distinguish colors. If a mammal is nocturnal - answer: There are fewer cones and a greater concentration of rods to collect the minimal light for night vision 123. In a study on the effects of cocaine on the brains of rats, two groups of animals were selected. Each day, Group A was injected with the drug dissolved in water, whereas the Group B was injected with water alone. In such a study group B is included as - answer: A control group 124. If blue light emits electrons from a photosensitive surface, then electrons must also be emitted it by - answer: Ultraviolet light 125. If all of the second-order consumers within an ecosystem of a region were removed, the most likely short-term effect would be - answer: An increase in the number of first-order consumers 126. During exercise, a person's respiratory rate increases due to - answer: An increase in CO2 concentration in the blood 127. Anaerobic respiration occurs in muscle tissue when it cannot get sufficient oxygen to function aerobically. Which of these conditions is most likely to directly result from this? - answer: Cramps 128. Amnesia in humans is the loss of memory. Which of these parts of the brain has been affected when someone is suffering from amnesia caused by head trauma? - answer: Cerebral cortex 129. A quantity that has both magnitude and direction is called a(n) - answer: vector 130. Which of these equations best illustrates a synthesis reaction? - answer: 2Na + CI2 - 2NaCI 131. He energy is absorbed in which of these phase changes? - answer: Br2 (l) - Br2(g) 132. A student focuses sunlight to a point with a thin converging (convex) lens. Which of these direct measurement can the student make as a result of this experiment? - answer: The approximate focal length of the lens 133. Guard cells which can be found in the leaves of plants are most closely associated with which of these processes? - answer: Evaporation of water from the plant 134. A drop of dilute ammonium hydroxide (NH4OH) pIs placed on one side of the slide containing a large number of swimming paramecium. Under this condition, which of these behaviors of the paramecia will be observed? - answer: They will all eventually swim away from the ammonium hydroxide. 135. Which of these organisms might be found in contaminated well water? - answer: Giardia 136. Which of this is an example of an emulsion? - answer: Mayonnaise 137. When your muscles atrophy, they - answer: waste away 138. Which of these instruments is used to measure the amount of heat exchanged in a system? - answer: Calorimeter 139. When a population is in Hardey-Weinberg equilibrium, which of these conditions must be present? - answer: The population is isolated from other populations. 140. Water freezes at 0°C. On the Kelvin temperature scale, this is equivalent to - answer: 273 K 141. The region of the brain most concerned with coordinating somatic motor function is the - answer: Cerebellum 142. The law of dominance was proposed by which of the following scientists? - answer: Mendel 143. The function of the myelin sheath That's surrounds many neurons is to - answer: Increase the rate of impulse transport 144. Most internal gas exchanges in the human respiratory tract occurs across the capillaries of which of these structures? - answer: Alveoli 145. How much current is drawn by a lightbulb that has a resistance of 100 R with the voltage of 110 V? (V = IR) - answer: 1.1 amperes 146. Which of these particles can only be found in the nucleus of an atom? - answer: Protons and neutrons 147. Unicellular organisms that have a nucleus and can swim with the aid of cilia are examples of - answer: Protozoans 148. The process of nuclear cell division in the cell reproduction of plants differ from mammals. A major difference is that - answer: Cell plates are synthesized 149. The inherited factors that are transmitted in an organism from generation to generation are called its A.) DNA B.) genotype C.) - answer: Genotype 150. The bending of a wave around an obstacle is known as A.) diffraction. B.) deflection. C.) refraction. D.) reflection. - answer: Diffraction 151. Iodize salt is used to prevent a human condition known as A.) rickets. B.) goiter. C.) scurvy. D.) beri-beri - answer: goiter 152. In varieties of matter, the term heterogeneous may be applied to A.) elements, but not compounds. B.) compounds, but not elements. C.) compounds and elements, but not mixtures. D.) mixtures, but not elements or compounds. - answer: Mixtures, but not elements or compounds. 153. Night blindness in humans is caused by a lack of A.) Vitamin A. B.) Niacin. C.) Calcium. D.) Vitamin D - answer: vitamin A 154. The energy associated with an object's position is termed A.) kinetic energy. B.) thermal energy. C.) photon energy. D.) potential energy. - potential energy. 155. The full set of genes in an individual is known as A.) specific DNA. B.) the human genome. C.) a chromosomal pattern. D.) cellular identity. - answer: The human genome 156. The Pap test can detect cancer in the female reproductive tract at an early stage, requiring cells scraped from A.) the vagina. B.) the fallopian tubes. C.) the uterus. D.) the cervix. - answer: the cervix. 157. When blood is filtered in the kidney and urine is produced, red blood cells and plasma proteins do not pass through the blood capillaries. This occurs because A.) the cell membrane of the capillary does not allow any substance to pass through it. B.) large molecules such as blood and plasma proteins do not fit through the permeable membrane, so they cannot enter the tubules in the kidney. C.) blood and plasma proteins are needed by the body, so they do not get filtered out into the kidney. D.) urine is composed of urea and water, so these are the only substances that will pass through the capillary membrane into the kidneys. - answer: large molecules such as blood and plasma proteins do not fit through the permeable membrane, so they cannot enter the tubules in the kidney 158. When three resistors of 10.0 ohms each are placed in series, the total resistance is A.) 3.3 ohms. B.) 10.0 ohms. C.) 30.0 ohms. D.) 40.6 ohms. - 30.0 ohms 159. When your muscles atrophy, they A.) waste away. B.) stiffen up. C.) become fatigued. D.) gain strength. - answer: Waste away 160. Which of these could be stopped by a sheet of paper? A.) Alpha particle. B.) Beta particle. C.) Gamma ray. D.) Cosmic ray. - answer: Alpha particle 161. Which of these is NOT an organic compound? A.) CH4 (methane). B.) C6H12O6 (glucose). C.) CH3COOH (acetic acid). D.) HCl (hydrochloric acid). - answer: HCl (hydrochloric acid). 162. Which of these is the correct sequence of chambers through which blood flows in the human heart and lungs? A.) Right ventricle; right atrium; lungs; left atrium; left ventricle. B.) Right atrium; right ventricle; lungs; left atrium; left ventricle. C.) Left ventricle; left atrium; lungs; right atrium; right ventricle. D.) Left atrium; left ventricle; lungs; right atrium; right ventricle. - answer: Right atrium; right ventricle; lungs; left atrium; left ventricle. 163. Which of these processes is used to free contaminated water of bacteria? A.) Filtering. B.) Passing it through charcoal. C.) Treating it with chlorine. D.) Allowing it to settle. - answer: Treating it with chlorine 164. Which of these structures contains valves to prevent blood from flowing in the wrong direction? A.) Veins. B.) Arteries. C.) Capillaries. D.) Lymph ducts. - answer: Veins 165. Which of these structures of the male reproductive system carries sperm cells from the testes to the lower part of the abdomen? A.) Urethra. B.) Seminiferous tubules. C.) Epididymis. D.) Vas deferens. - Vas deferens. 166. A method for determining the blood alcohol content of a subject is to A.) do a Mantoux test. B.) do a Dick test. C.) use a Breathalyzer. D.) inspect the size of the pupils. - answer: use a Breathalyzer 167. Guard cells which can be found in the leaves of plants are most closely associated with which of these processes? - Evaporation of water from the plant 168. Human testes produce - answer: spermatozoa 169. If the medulla of the brain in a human was damaged, which of these conditions would most likely result? A.) Inability to remember. B.) Difficulty in breathing. C.) Inability to speak. D.) Blurred vision. - answer: Difficulty in breathing 170. In diagnostic testing, the electroencephalogram permits the physician to A.) examine the impulses of the specialized muscle cells of the heart. B.) examine the impulses of the nerve cells within the brain. C.) measure the pressure within the eye. D.) measure the amount of air upon exhalation. - answer: examine the impulses of the nerve cells within the brain 171. In ecological succession, the first living thing to colonize a hitherto barren area is called a A.) producer. B.) primary consumer. C.) pioneer organism. D.) carnivore. - answer: pioneer organism 172. To sterilize a metal probe in the office, a dentist could use a steam sterilizer. If unavailable, the next most effective method to sterilize the instrument would be - boiling it in water for 15 minutes. 173. Iodized salt is used to prevent a human condition known as - answer: goiter 174. The organ that filters metabolic waste from the blood is the A.) small intestine. B.) liver. C.) kidney. D.) stomach. - answer: kidney 175. Unicellular organisms that have a nucleus and can swim with the aid of cilia are examples of - answer: protozoans 176. Which of these conditions is associated with smoking? - answer: emphysema 177. Which of these organisms use nitrogen directly from the air? - answer: Blue-green algae 178. Which of these pairs of units measures the same quantity? - answer: Calorie and joule 179. Which of these processes is responsible for the recorded production of CO2 by yeast cells from sugar solution? - answer: Anaerobic respiration 180. Which of these substances contains a nonpolar covalent bond? A.) NaCl B.) HBr C.) O2 D.) NH3 - answer: O2 181. Which of these processes occurs at a neuromuscular junction? - answer: Impulse transmission. 182. Which of these processes is illustrated by the spreading out of ammonia vapor in a closed room? - answer: Diffusion. 183. When a drop of dilute nitric acid is added to water surrounding a hydra, the animal draws in its tentacles. The acid is acting as A.) a hormone. B.) an impulse. C.) a stimulus. D.) a response. - answer: a stimulus 184. The physics principle that is primarily used in developing a rollercoaster ride is A.) centripetal force. B.) specific gravity. C.) (no) quantum energy. D.) (no) certainty principle. - answer: centripetal force. 185. Sugar molecules enter a cell against a concentration gradient by the process of A.) passive diffusion. B.) facilitated diffusion. C.) osmosis. D.) active transport. - answer: active transport 186. The light sensitive cells of the eye are called rods and cones. Which of these layers of the eye are they found in? A.) Cornea. B.) Retina. C.) Sclera. D.) Choroid. - answer: retina 187. Substance Y is soluble only in nonpolar solvents and does not conduct electricity, either in the solid or liquid phases. Y is most probably A.) an ionic substance. B.) a polar substance. C.) a nonpolar substance. D.) a metallic substance. - answer: a nonpolar substance. 188. Reducing the use of aeresol cans has contributed to the decrease of A.) the green house effect. B.) the destruction of the ozone layer C.) thermal pollution. D.) acid rain. - answer: the destruction of the ozone layer 189. If the night temperature drops 50 degrees, the roadrunner's internal energyconservation permits a lowering of body temperature to A.) 101°F B.) 98°F C.) 94°F D.) 90°F - answer: 94°F 190. Ductless glands in the human body secrete A.) enzymes. B.) mucus. C.) hormones. D.) metabolic wastes. - answer: hormones. 191. All the glucose filtered from the blood in the glomerulus into the Bowman's capsule of the kidney nephron is returned to the tissue fluid while passing along the proximal tubule. This rapid return is effected by the process of - answer: active transport 192. A material that settles out of a reaction is termed a(n) A.) precipitate B.) product C.) reactant D.) solid - answer: precipitate 193. A tincture is a solution in which A.) alcohol is the solvent. B.) water is the solvent. C.) alcohol is the solute. D.) water is the solute. - answer: alcohol is the solvent 194. 30 students in a class carefully measure the length and width of 20 peanut shells. They also count the number and note the size of the peanuts inside. This information is recorded on various graphs showing the numbers of nuts and the different sizes. The collected evidence of the peanuts gives the students an idea of the extent of A.) natural selection within a species. B.) variation within a species. C.) evolution within a species. D.) speciation from a species. - answer: variation within a species 195. Within a living cell, the oxygen (O2) from a mixture of O2 and carbon dioxide (CO2) is used up. This creates a concentration gradient across the cell membrane, drawing O2 across the membrane from the outside in, a process known as A.) Osmosis. B.) Active transport. C.) Diffuision. D.) Cellur respiration. - answer: Diffusion 196. While working in the chemistry laboratory, a student spills dilute hydrochloric acid on her hand. What is the first action this student should take? - answer: Flush her hand with large quantities of water 197. A person who was in an auto accident has formed a blood clot at the site of the injury. One event that can lead to formation of a blood clot is that A.) red blood cells release hemoglobin. B.) bone marrow cells decrease platelet production. C.) white blood cells release antibodies. D.) ruptured platelets release thromboplastin. - answer: ruptured platelets release thromboplastin 198. Which part of the cell structure controls the passage of materials into and out of the cell? A.) Golgi apparatus. B.) Ribosome. C.) Nuclear membrane. D.) Plasma membrane. - answer: Plasma membrane 199. 1 kilogram (kg) of solid X at 10°C and 1 kg of solid Y at 10°C each absorb 5 joules of heat energy. The final temperatures of X and Y are 15°C and 20°C, respectively. Compared to X, Y must have a lower A.) specific heat. B.) conductive heat. C.) heat of fusion. D.) heat of vaporization. - answer: specific heat 200. A drop of dilute ammonium hydroxide (NH4OH) is placed on one side of a slide containing a large number of swimming paramecium. Under this condition, which of these behaviors of the paramecia will be observed? A.) They will eventually all swim toward the ammonium hydroxide. B.) They will show no net change in behavior to the ammonium hydroxide. C.) They will all be instantly killed by the ammonium hydroxide. D.) They will eventually all swim away from the ammonium hydroxide. - answer: They will eventually all swim away from the ammonium hydroxide. 201. A woman suddenly chokes on a piece of food and clutches frantically at her throat. A.) An immediate remedy is to have her bend forward and tell her to cough. B.) insert a finger or a blunt object toward the back of the mouth. C.) apply quick, hard pressures successively to her abdomen, just beneath her diaphragm. D.) phone "emergency" for help - answer: apply quick, hard pressures successively to her abdomen, just beneath her diaphragm. 202. In varieties of matter, the term heterogeneous may be applied to A.) elements, but not compounds. B.) compounds, but not elements. C.) compounds and elements, but not mixtures. D.) mixtures, but not elements or compounds. - answer: mixtures, but not elements or compounds. 203. The bending of a wave around an obstacle is known as A.) diffraction. B.) deflection. C.) refraction. D.) reflection. - answer: diffraction 204. The process of nuclear cell division in the cell reproduction of plants differs from mammals. A major difference is that A.) homologous chromosomes are paired. B.) centrioles are replicated. C.) spindle fibers are missing. D.) cell plates are synthesized. - answer: homologous chromosomes are paired 205. Which of these particles can only be found in the nucleus of an atom? A.) protons, only. B.) electrons, only. C.) protons and neutrons. D.) neutrons and electrons. - answer: protons and neutrons. 206. According to the Ideal Gas Equation (PV = nRT), if the temperature and amount of gas are kept constant, what will be the effect of an increase in pressure on the volume of a gas? A.) As the pressure increases, the volume decreases. B.) As the pressure increases, the volume increases. C.) The volume equalizes despite pressure changes. D.) The volume and pressure are unrelated - answer: As the pressure increases, the volume decreases. 207. As an object falls freely near the surface of the earth, its speed increases, representing a transformation of A.) friction to kinetic energy. B.) kinetic energy to friction. C.) kinetic energy to potential energy. D.) potential energy to kinetic energy. - answer: potential energy to kinetic energy. 208. At room temperature, which of these substances exists as diatomic molecules? A.) Carbon. B.) Iron. C.) Neon. D.) Oxygen. - answer: Oxygen 209. Coulomb's law is most closely associated with A.) gravitational fields. B.) fluid flow. C.) electric charges. D.) nuclear forces. - answer: electric charges. 210. During exercise, a person's respiratory rate increases due to A.) an increase in CO2 concentration in the blood. B.) a decrease in O2 concentration in the lungs. C.) an increase in hemoglobin in the blood. D.) a decrease in CO2 concentration in the blood. - answer: an increase in CO2 concentration in the blood. 211. If a person is fasting for 24 hours and ingests no carbohydrates, the liver will provide for the body's need by A.) converting glycogen into glucose. B.) breaking down red blood cells. C.) emulsifying fat. D.) producing more bile. - answer: converting glycogen into glucose. 212. If all of the second-order consumers within an ecosystem of a region were removed, the most likely short-term effect would be A.) a decrease in decomposers. B.) an increase in producers. C.) an increase in the number of first-order consumers. D.) a decrease in the number of first-order consumers. - answer: an increase in the number of first-order consumers. 213. In order to observe the endoplasmic reticulum in a cell, a scientist would use A.) a light-microscope. B.) an electron microscope. C.) an ultracentrifuge. D.) dissecting instruments. - answer: an electron microscope. 214. Muscles are attached to bone by which of these structures? A.) Cartilage. B.) Ligament. C.) Capsula. D.) Tendon. - answer: Tendon. 215. Sodium will react most readily with A.) potassium. B.) helium. C.) chlorine. D.) boron. - answer: chlorine 216. The amplitude of a sound wave is most closely related to its A.) pitch. B.) speed. C.) wavelength. D.) loudness. - answer: loudness 217. The full set of genes in an individual is known as A.) specific DNA. B.) the human genome. C.) a chromosomal pattern. D.) cellular identity. - answer: the human genome. 218. The physics principle that is primarily used in developing a rollercoaster ride is A.) centripetal force. B.) specific gravity. C.) quantum energy. D.) certainty principle. - answer: centripetal force. 219. The surface of the moon has almost no atmosphere and is one-sixth the gravitational acceleration of the earth. If a feather and a hammer were dropped near the surface of the moon A.) the feather would hit the surface first because it has less mass. B.) the hammer would hit the surface first because it has more mass. C.) the feather and the hammer would hit the surface at the same time. D.) it is impossible to predict which would hit the surface first without more information. - answer: the feather and the hammer would hit the surface at the same time. 220. The vertical columns on the periodic chart are known as A.) periods. B.) ions. C.) metalloids. D.) groups. - answer: groups 221. The horizontal columns on the periodic chart are known as A.) periods. B.) ions. C.) metalloids. D.) groups. - answer: periods 222. What is the pH of a solution whose H+ ion concentration is 1 x 10-2 mole per liter? A.) 1 B.) 2 C.) 12 D.) 13 - answer: 2 223. When a drop of dilute nitric acid is added to water surrounding a hydra, the animal draws in its tentacles. The acid is acting as A.) a hormone. B.) an impulse. C.) a stimulus. D.) a response. - answer: a stimulus 224. When two atoms share a pair of electrons, the bond between them is called A.) electrovalent. B.) covalent. C.) ionic. D.) metallic. - answer: covalent 225. Which aspect of a simple machine is represented by the ratio work output to work input? A.) Power expended. B.) Efficiency. C.) Ideal mechanical advantage. D.) Actual mechanical advantage. - answer: Efficiency 226. Which of these arrangements of atoms is found in all alcohols? A.) C=C B.) C-O-C C.) C=O D.) C-OH - answer: C-OH 227. Which of these changes occurs in the kidneys when a person becomes dehydrated? A.) The kidneys filter more water and there is less reabsorption of water from the blood. B.) The filtration rate of water remains constant and the reabsorption of water increases. C.) The filtration rate of water increases and the reabsorption of water remains constant. D.) No changes occur in kidney function. - answer: The filtration rate of water remains constant and the reabsorption of water increases. 228. Which of these pH values represents the most basic solution? A.) 2 B.) 4 C.) 12 D.) 14 - answer: 14 229. which of the following would be classified as a vertebrate A.) earthworm B.) starfish C.) snake D.) lobster - answer: snake 230. the human diaphragm can be described as A.) the muscle that protects the entrance tot he larynx B.) the location in the lungs where the diffusion of respiratory gasses occurs C.) the muscular sheet that assists in the mechanics of breathing D.) the tube down which air passes on its way to the lungs - answer: a muscular sheet that assists in the mechanics of breathing 231. which of these conditions most likely explains the sudden death of many fish in a river on a hot day in summer? A.) an increased number of predators B.) an increased growth of algae C.) a reduced food supply D.) a reduced amount of dissolved oxygen - answer: a reduced amount of dissolved oxygen 232. the energy associated with an object's motion is called A.) potential energy B.) nuclear energy C.) kinetic energy D.) thermal energy - answer: kinetic energy 233. the frequency of a sound wave is directly related to its A.) loudness B.) pitch C.) timbre D.) resonance - answer: pitch 234. Which measurement shows the normal pulse and blood pressure values for a patient? A.) 55/min, 125/95 mm/hg B.) 72/min, 120/80 mm/hg C.) 60/min, 100/75 mm/hg D.) 80/min, 72/120 mm/hg - answer: 72/min, 120/80 mm/hg 235. When the rib cage moves upward and outward and the diaphragm flattens out A.) air is expelled from lungs B.) air is drawn into lungs C.) air pressure in the lungs rises D.) there is no change in the air pressure in the lungs - answer: air is drawn into lungs 236. The term that describes how the stem of a plant grows toward the light is A.) -phototropism B.) -geotropism C.) +phototropism D.) +geotropism - answer: +phototropism 237. The electrical activity of the brain is recorded as an A.) electrocardiogram B.) angiogram C.) electroencephalogram D.) electromotor response - answer: electroencephalogram 238. the first living thing found colonizing a hitherto barren area is called a A.) producer B.) primary consumer C.) pioneer organism D.) carnivore - answer: pioneer organism 239. Photographs in an old family album reveal that an area now covered with shrugs and small trees and occasionally gets swampy in the spring was once a pond, this is an example of A.) food chain B.) ecological succession C.) an ecosystem D.) the colonization of barren land - answer: ecological succession 240. If attempts to decompose a substance prove unsuccessful, the substance is probably A.) an element B.) a compound C.) a mixture D.) a liquid - answer: an element 241. A solution with hydrogen ion concentration of 1x10-7 is A.) acidic B.) basic C.) neutral D.) alkaline - answer: neutral 242. An animal who's retina has no cone cells probably can not A.) see at all B.) distinguish color C.) see 3D objects D.) distinguish shades of black and white - answer: distinguish color 243. the average kinetic energy of a substance increases when A.) its temp increase B.) its temp decreases C.) it changes from liquid to solid D.) it changes from liquid to gas - answer: its temp increases 244. within which of these structures of the female reproductive tract is the human egg fertilized A.) uterus B.) fallopian tube C.) vagina D.) ovary - answer: fallopian tube 245. The xylem vessels of a plant carry A.) food down from the leaves B.) carbon dioxide into the leaves C.) chlorophyll to assist in photosynthesis D.) water up from the roots - answer: water up from the roots 246. A small foil disk was attached to a leaf of a plant that was placed in a well lit area, after 2 hours the leaf was removed from the plant and chlorophyll was extracted from it. how would the leaf appear after it was stained with lug's solution (iodine) A.) uniformly black B.) white C.) mostly black except for a white area corresponding to the presence of the disk D.) mostly white except for a black area corresponding to the presence of the disk - answer: mostly black except for a white area corresponding to the presence of the disk 247. When a human RBC is placed in distilled water it will A.) swell up and eventually burst B.) shrink in size C.) stay the same size D.) actively pump water out of the cell - answer: swell up and eventually burst 248. The enzymes found in the stomach and small intestine that hydrolyze fats are called A.) amylases B.) peptidases C.) proteases D.) lipases - answer: lipases 249. Blood returning to the heart from the body travels through the vena cave and enters the A.) RA B.) RV C.) LA D.) LV - answer: RA 250. a particle of light energy is called a A.) positron B.) neutron C.) betatron D.) photon - answer: photon 251. A simple series circuit carries a current of 3.0 amp when the potential difference across it is 24.0 volts, the resistance of this circut is A.) 0.125 omega B.) 8.0 omega C.) 27.0 omega D.) 72.0 omega - answer: 8.0 omega 252. Tissue that is striated with multinucleate cells is found at A.) the heart B.) the stomach C.) the brain D.) the arm muscle - answer: the arm muscle 253. In which of these media will monochromatic light have the lowest speed, refractive indices given A.) lucite 1.50 B.) diamond 2.42 C.) water 1.33 D.) air 1.00 - answer: diamond 2.42 254. Although it is not possible to experiment with human beings to obtain genetic info, data on human genetics have been obtained from A.) observing human eggs under a microscope B.) listing the genetic characteristics of individual humans C.) fertilizing human eggs in a glass dish D.) making family trees that include information about certain diseases that related individuals have had - answer: making family trees that include information about certain diseases that related individuals have had 255. The region of the human brain where speech function and conscious thought processes are located is called the A.) cerebrum B.) cerebellum C.) medulla oblongata D.) hypothalamus - answer: cerebrum 256. a structure associated with osmosis in the amoeba and paramecium is the A.) nucleus B.) mitochondria C.) contractile vacuole D.) ribosome - answer: contractile vacuole 257. What is the correct voltage of a chemical cell that has reached equilibrium A.) 1v B.) greater than 1v C.) between 0 and 1v D.) 0v - answer: 0v 258. A cross between a plant with red flowers and one bearing white flowers produces pink flowers, this is an example of A.) incomplete dominance B.) mendel's law of independent assortment C.) mendel's law of segregation D.) sex linkage - answer: incomplete dominance 259. a chemical change always involves the formation of a A.) compound B.) gas C.) new element D.) new substance - answer: new element 260. If a solution turns litmus blue, it will also turn phenolphthalein A.) pink B.) green C.) yellow D.) colorless - answer: pink 261. The interaction of bone and muscle that results in a specific musculoskeletal movement can best be characterized by the physical principle of a A.) pulley B.) spring C.) wave D.) lever - answer: lever 262. One possible reason that animals such as mice, moles, and rabbits have such rapid rates of reproduction is that they A.) are herbivorous B.) live together in burrows C.) are predators D.) serve as prey for many other animals - answer: serve as prey for many other animals 263. Solid objects become positively charged by A.) losing protons B.) gaining protons C.) losing electrons D.) gaining electrons - answer: losing electrons 264. Which of these statements accurately describes what happens to an object as it falls freely near the surface of the earth A.) its kinetic an potential energies decrease B.) its kinetic energy decreases and its potential energy increases C.) its kinetic energy increases and its potential energy decreases D.) its kinetic and potential energies increase - answer: its kinetic energy increases and its potential energy decreases 265. Which process produces the energy in modern nuclear reactors A.) fusion B.) alpha decay C.) fission D.) electron capture - answer: fission 266. Which molecule contains nonpolar covalent bonds A.) NaCl B.) Cl2 C.) Her D.) CO2 - answer: Cl2 267. The scientific name of the cat is Felis domestics, the term Felis indicates which of these levels of classification A.) genus B.) species C.) family D.) kingdom - answer: genus 268. Different types of white blood cells are classified histologically, they are distinguished from one another base on their morphology and their A.) cell size B.) number in a sample of blood C.) staining characteristics D.) ability to engulf bacteria - answer: ability to engulf bacteria 269. Which of the following is an example of a physical property? a substance's ability to A.) react with an acid B.) oxidize a compound C.) decomose D.) dissolve in water - answer: dissolve in water 270. Coulomb's law is most closely associated with - answer: electric charges.