General Science

200 General Science practice questions, each with the correct answer and the method behind it.

1. Which organelle produces most of a cell's usable energy?Mitochondrion
2. Which structure is found in plant cells but not in animal cells?Cell wall
3. Mitosis produces how many daughter cells, and how do they compare to the parent?Two, genetically identical to the parent
4. The instructions carried in DNA are organised into units calledgenes
5. A trait that appears only when an organism inherits the same allele from both parents is calledrecessive
6. Which molecule carries the genetic message from the nucleus to the ribosome?Messenger RNA
7. Which chamber of the heart pumps blood out into the aorta?Left ventricle
8. Gas exchange in the lungs takes place in thealveoli
9. Which organ produces bile?The liver
10. The smallest bones in the human body are found in theear
11. Insulin, which regulates blood sugar, is produced by thepancreas
12. Which part of the brain controls balance and coordinated movement?The cerebellum
13. Red blood cells carry oxygen by binding it to which substance?Haemoglobin
14. Which nutrient supplies the most calories per gram?Fat
15. A prolonged deficiency of vitamin C causes which disease?Scurvy
16. A vaccine protects against a disease byprompting the body to make antibodies in advance
17. Which gas do plants release during photosynthesis?Oxygen
18. Organisms that make their own food are calledproducers
19. In a food chain, roughly how much of the energy at one level passes to the next?About one tenth
20. Bacteria that convert nitrogen gas from the air into compounds plants can use carry outnitrogen fixation
21. The release of water vapour from plant leaves into the atmosphere is calledtranspiration
22. The atomic number of an element equals the number ofprotons in the nucleus
23. Which subatomic particle carries no electrical charge?The neutron
24. A chemical bond formed when one atom transfers electrons to another isan ionic bond
25. A solution with a pH of 3 isacidic
26. The change of a substance directly from solid to gas, without melting first, is calledsublimation
27. Elements in the same column of the periodic table sharesimilar chemical properties
28. In a balanced chemical equation, what must be equal on both sides?The number of atoms of each element
29. In a solution, the solvent is the substance thatdoes the dissolving
30. Speed together with direction is known asvelocity
31. Which statement expresses Newton's third law of motion?Every force is matched by an equal force in the opposite direction
32. In physics, work equals force multiplied bydistance
33. Heat passing through a metal spoon left in hot soup travels byconduction
34. At sea level, water boils at what temperature on the Celsius scale?100 degrees
35. An approaching siren sounds higher in pitch than a receding one becausethe sound waves reaching you are compressed
36. Light bending as it passes from air into water is calledrefraction
37. A magnet's field is strongest at itspoles
38. Rock formed from cooled and hardened magma is classified asigneous
39. Earthquakes occur most frequentlyalong boundaries between tectonic plates
40. The ozone layer, which absorbs much of the Sun's ultraviolet light, lies in thestratosphere
41. The passage of a cold front over an area typically bringsbrief heavy storms followed by cooler, drier air
42. Which mineral is the hardest on the Mohs scale?Diamond
43. Fossils are found most commonly in which type of rock?Sedimentary
44. Ocean tides are caused mainly bythe gravitational pull of the Moon
45. Which planet orbits closest to the Sun?Mercury
46. Earth has seasons becauseits axis is tilted relative to its orbit
47. A lunar eclipse occurs whenEarth passes between the Sun and the Moon
48. The Sun is classified asa star
49. In an experiment, the variable the researcher deliberately changes is called theindependent variable
50. A control group is included in an experiment in order toprovide a baseline for comparison
51. Which organelle packages proteins and prepares them for transport out of the cell?The Golgi apparatus
52. Chloroplasts owe their colour to which pigment?Chlorophyll
53. Compared with the parent cell, the cells produced by meiosis havehalf the number of chromosomes
54. In the DNA double helix, which bases pair with each other?Adenine with thymine, cytosine with guanine
55. A permanent change in the sequence of an organism's DNA is called amutation
56. Bacterial cells differ from plant and animal cells chiefly in that bacteriahave no true nucleus
57. Which vessels carry blood away from the heart?Arteries
58. When you breathe in, the diaphragmcontracts and flattens, drawing air in
59. Most absorption of nutrients from food takes place in thesmall intestine
60. Voluntary movements, such as lifting an arm, are produced by which type of muscle?Skeletal muscle
61. The main function of the kidneys is tofilter waste products from the blood
62. White blood cells are produced mainly in thebone marrow
63. A neuron carries information along its length in the form ofan electrical impulse
64. Which vitamin can the body manufacture when skin is exposed to sunlight?Vitamin D
65. Antibiotics are effective againstbacteria but not viruses
66. The main role of dietary fibre is tokeep material moving through the digestive tract
67. An animal that eats only plants is calleda herbivore
68. The range of different species living in a particular area is called itsbiodiversity
69. Decomposers benefit an ecosystem byreturning nutrients from dead matter to the soil
70. A biome is classified as a desert based mainly on itslow annual rainfall
71. A relationship in which one species benefits and the other is neither helped nor harmed is calledcommensalism
72. What is the chemical formula for water?H2O
73. A substance made of two or more elements chemically bonded together isa compound
74. Which of the following is a physical change rather than a chemical one?Ice melting into water
75. Which gas makes up the largest share of Earth's atmosphere?Nitrogen
76. A catalyst affects a chemical reaction byspeeding it up without being used up itself
77. Compared with non-metals, metals generallyconduct heat and electricity well
78. The noble gases are almost completely unreactive becausetheir outer electron shells are already full
79. Two isotopes of the same element differ in their number ofneutrons
80. In the metric system, force is measured innewtons
81. A single fixed pulley is useful because itchanges the direction of the effort without reducing it
82. The energy stored in a stretched spring iselastic potential energy
83. Sound cannot travel througha vacuum
84. Which colour of visible light has the longest wavelength?Red
85. An object's inertia, its resistance to a change in motion, depends on itsmass
86. In a simple series circuit, what happens when one bulb burns out?Every bulb in the circuit goes out
87. Electrical power is measured inwatts
88. Metamorphic rock is formed whenexisting rock is altered by heat and pressure
89. Which is the innermost layer of the Earth?The inner core
90. Which cloud type is most associated with steady rain lasting many hours?Nimbostratus
91. Soil is formed mainly byrock breaking down and mixing with decayed matter
92. A barometer is an instrument for measuringair pressure
93. The breaking down of rock where it lies, without being carried away, is calledweathering
94. Most of Earth's fresh water is held inice caps and glaciers
95. A light-year is a unit ofdistance
96. The phases of the Moon are caused byhow much of its sunlit side faces Earth
97. Which force keeps the planets in orbit around the Sun?Gravity
98. Our solar system lies within which galaxy?The Milky Way
99. For a hypothesis to be scientifically useful, it must above all betestable
100. Which SI unit is used to measure mass?The kilogram
101. Which cell structure reads messenger RNA to assemble a protein?The ribosome
102. The organelle that stores a cell's DNA and directs its activities is thenucleus
103. The thin barrier that controls which substances enter and leave a cell is thecell membrane
104. Compared with an animal cell, a mature plant cell usually hasone large central vacuole taking up most of its volume
105. Chloroplasts are the site in a plant cell wherephotosynthesis converts light into stored energy
106. Unlike mitosis, meiosis results infour cells, each with half the chromosome number
107. Mitosis is best described as the type of division used forgrowth and the repair of tissue
108. The double helix shape of the DNA molecule was described byWatson and Crick
109. Which order correctly describes protein synthesis?Transcription of DNA into mRNA, then translation of mRNA into protein
110. An organism's observable traits, such as eye color, make up itsphenotype
111. Crossing two heterozygous parents (Aa x Aa) for a trait with simple dominance, what fraction of offspring is expected to show the recessive phenotype?One quarter
112. A typical human body cell contains how many chromosomes?46
113. Which blood vessels return blood to the heart?Veins
114. Which chamber of the heart receives oxygen-poor blood returning from the body?Right atrium
115. The main function of the alveoli's thin, moist walls is tolet oxygen and carbon dioxide diffuse across easily
116. Food travels from the mouth to the stomach through theoesophagus
117. Enzymes that begin breaking down starch are first released in themouth
118. Which part of the brain regulates automatic functions such as heart rate and breathing?The medulla
119. The gap between two neurons, across which a nerve signal passes chemically, is called asynapse
120. A joint where two bones are connected by fibrous tissue that allows almost no movement, such as in the skull, is calleda fibrous joint
121. Tendons connect muscle tobone
122. The gland often called the body's master gland, because it directs the activity of several other glands, is thepituitary gland
123. Adrenaline, released in response to sudden stress or danger, is produced by theadrenal glands
124. Lymphocytes are a type of white blood cell whose main job is torecognize and attack specific pathogens
125. Urine leaves the kidneys and travels to the bladder through theureters
126. A normal adult resting heart rate falls in roughly which range?60 to 100 beats per minute
127. Which of these is classified as a macronutrient the body needs in large amounts?Protein
128. Roughly how many calories does one gram of carbohydrate supply?4
129. A long-term shortage of iodine in the diet most often leads toan enlarged thyroid gland, or goitre
130. A diet consistently low in vitamin A is most likely to causedifficulty seeing in dim light
131. Which of the following is caused by a virus rather than a bacterium?The common cold
132. After recovering from a disease, the body often develops long-lasting protection against it because ofmemory cells left behind by the immune response
133. The raw materials plants take in to carry out photosynthesis arecarbon dioxide and water
134. Cellular respiration in both plants and animals releases usable energy bybreaking down sugar with oxygen
135. An animal that eats both plants and other animals is calledan omnivore
136. In a food chain, the organisms that eat producers directly are calledprimary consumers
137. A biome characterized by long, harsh winters and forests dominated by conifers is thetaiga
138. The specific role an organism plays within its ecosystem, including what it eats and where it lives, is called itsniche
139. In the carbon cycle, carbon dioxide is removed from the atmosphere mainly byphotosynthesis in plants and algae
140. Water that soaks into the ground and collects underground is calledgroundwater
141. In a flowering plant, the structure that develops into a seed after fertilization is theovule
142. In the standard biological classification system, which level groups the widest range of organisms together?Kingdom
143. Which subatomic particle carries a negative electrical charge?The electron
144. Almost all of an atom's mass is concentrated in itsnucleus
145. Elements in the periodic table are arranged in order of increasingatomic number
146. Elements found on the far left of the periodic table, such as sodium and potassium, are classified asalkali metals
147. A bond in which two atoms share a pair of electrons is calleda covalent bond
148. Table salt dissolves easily in water largely becausewater's polar molecules pull apart the ionic lattice
149. A reaction that releases heat to its surroundings is calledexothermic
150. A reaction in which two or more simple substances combine to form a single more complex product is calleda synthesis reaction
151. A solution with a pH of 10 isbasic
152. When an acid and a base react completely with each other, the products are typicallya salt and water
153. The change of state from a liquid to a gas is calledevaporation
154. As a gas is cooled and its particles slow down and pack closer together, it will eventuallycondense into a liquid
155. Salt water is an example ofa homogeneous mixture
156. Filtration is a technique used to separatean undissolved solid from a liquid
157. An atom of carbon-12 has 6 protons and 6 neutrons. How many electrons does the neutral atom have?6
158. Elements in the second-to-last column of the periodic table, such as chlorine and fluorine, are calledhalogens
159. Acceleration is defined as the rate of change ofvelocity
160. A car travels 150 miles in 3 hours at a constant speed. What is its average speed?50 mph
161. According to the law of inertia, a puck sliding across frictionless ice wouldcontinue sliding at the same speed and direction forever
162. According to Newton's second law, if the same force is applied to two objects, the one with greater mass will havesmaller acceleration
163. Power is best defined as therate at which work is done
164. A machine does 600 joules of work in 20 seconds. What power does it develop?30 watts
165. A ball held above the ground has energy stored due to its position, calledgravitational potential energy
166. The law of conservation of energy states that in a closed system, energyis neither created nor destroyed, only transformed
167. Warm air rising away from a radiator and carrying heat through a room is an example of heat transfer byconvection
168. On the Fahrenheit scale, water freezes at what temperature?32 degrees
169. The number of complete wave cycles passing a point each second is called the wave'sfrequency
170. The loudness of a sound is most directly related to the wave'samplitude
171. A converging lens, thicker in the middle than at the edges, forms an image bybending light rays inward to a focus
172. Which type of electromagnetic radiation has a shorter wavelength than visible light?Ultraviolet
173. Electric current is measured inamperes
174. Passing an electric current through a coil of wire wrapped around an iron core willproduce a temporary magnetic field, an electromagnet
175. Layers of sand and mud that are compressed and cemented together over time form which type of rock?Sedimentary
176. In the rock cycle, an existing rock can become any of the three rock types depending on theprocesses it is exposed to, such as heat, pressure, or weathering
177. A volcano is most likely to form wheremagma rises through weaknesses in the crust
178. An earthquake's magnitude is commonly reported using theRichter scale
179. A naturally occurring, solid, inorganic substance with a fixed chemical composition and crystal structure is called amineral
180. Topsoil that is rich, dark, and especially good for growing crops is typically high inorganic humus
181. Water vapour cooling and turning back into liquid droplets, forming clouds, is calledcondensation
182. The zone where a river meets the sea and fresh water mixes with salt water is calledan estuary
183. A warm front passing over an area typically bringsa long period of light, steady rain followed by warmer air
184. An anemometer is an instrument used to measurewind speed
185. Weather, including clouds, storms, and daily temperature changes, occurs mainly in thetroposphere
186. The buildup of greenhouse gases such as carbon dioxide contributes to climate change chiefly bytrapping heat that would otherwise radiate back into space
187. Scientists estimate the age of a rock or fossil using the known decay rate of certain isotopes, a method calledradiometric dating
188. In an undisturbed sequence of sedimentary rock layers, the oldest layer is normally foundat the very bottom
189. Which of these planets is classified as a gas giant?Jupiter
190. The belt of rocky debris orbiting mainly between Mars and Jupiter is called theasteroid belt
191. During a solar eclipse, what is happening in space?the Moon slides into the line connecting Earth and the Sun
192. Tides are generally highest, called spring tides, whenthe Sun and Moon pull in roughly the same direction
193. The energy radiated by the Sun is generated bynuclear fusion converting hydrogen into helium
194. When a star much more massive than the Sun exhausts its fuel, it is likely to end its life as asupernova explosion
195. The leading scientific model for the origin of the universe, describing its expansion from an extremely hot, dense state, is called theBig Bang theory
196. A galaxy shaped like a flattened disc with curved arms winding out from its center, such as our own, is calledspiral
197. In an experiment, the outcome that is measured to see how it responds to the variable being changed is called thedependent variable
198. In the SI system, length is measured inmetres
199. A graduated cylinder is a piece of laboratory equipment used mainly to measureliquid volume
200. On a line graph plotting an experiment's results, the steepness of the line at any point represents therate at which the measured quantity is changing