front 1 Acceleration | back 1 Any change in the speed or direction of motion of an object. |
front 2 Acid | back 2 A substance with a pH less than 7.0 that releases hydrogen ions in a water solution; for example, vinegar. |
front 3 Acid Rain | back 3 Rain that is highly acidic because of sulfur oxides, nitrogen oxides, and other air pollutants dissolved into it; can damage plant and animal life. |
front 4 Activation Energy | back 4 The energy needed to enable a chemical reaction to take place. |
front 5 Adaptation | back 5 A process that helps an organism survive and function in its environment. |
front 6 Adequacy | back 6 Being satisfactory; being sufficient for a job. |
front 7 Aging | back 7 The changes that bring about the decline of an organism. |
front 8 Air Mass | back 8 A large body of air that has the same moisture and temperature throughout. |
front 9 Air Pressure | back 9 The weight of the atmosphere. |
front 10 Air Resistance | back 10 Friction caused by air. |
front 11 Alimentary Canal | back 11 The tube that makes up the digestive canal. |
front 12 Allele | back 12 A different form of a gene. |
front 13 Alpha Particle | back 13 A radioactive particle made up of two protons and two neutrons bound tightly together. |
front 14 Alternating Current | back 14 A current in which the electrons flow first in one direction and then in the opposite direction. |
front 15 Alveoli | back 15 Small air sacs in the lungs at the end of the bronchioles where oxygen passes in the blood and carbon dioxide is released from the blood. |
front 16 Amino Acids | back 16 The building blocks of proteins. |
front 17 Amniocentesis | back 17 A procedure that is used to examine fetal cells to identify certain types of genetic disorders present in a fetus. |
front 18 Amniotic Egg | back 18 A covering that protects and nourishes a developing embryo. |
front 19 Amplitude | back 19 The distance between the rest position and crest of a wave. |
front 20 Antibodies | back 20 Substances produced by the body's immune system that fight diseases. |
front 21 Antigen | back 21 A protein on the surface of a pathogen. |
front 22 Aorta | back 22 A large artery that carries oxygen-rich blood from the heart to other parts of the body. |
front 23 Applying ideas | back 23 Taking information learned one set of circumstances and using it in another situation. |
front 24 Artery | back 24 A blood vessel that carries blood away from the heart. |
front 25 Asexual Reproduction | back 25 A method of reproduction in which an organism is produced from a single cell. |
front 26 Assess | back 26 To determine the importance, adequacy, or significance of something. |
front 27 Assumption | back 27 A belief that something is true without checking its validity. |
front 28 Asteroid | back 28 A small celestial body, sometimes called a minor planet, that revolves around the sun. |
front 29 Astronomy | back 29 The study of all celestial bodies in the universe. |
front 30 Atmosphere | back 30 The layers of gases that surround the Earth. |
front 31 Atom | back 31 The smallest particle of an element that can exist alone. |
front 32 Atomic Mass | back 32 The sum of protons and neutrons in the nuclease of an atom. |
front 33 Atomic Number | back 33 The number of protons in the atom. |
front 34 ATP | back 34 A compound in which energy is stored for later use in a cell. |
front 35 Atrium | back 35 One of the upper chambers of the heart (plural, atria) |
front 36 Axis | back 36 The imaginary line running through Earth's center from the North Pole from the South Pole on which the planet rotates. |
front 37 Backbone | back 37 A segmented column of bones. |
front 38 Bacteria | back 38 A one-celled organism that has DNA. |
front 39 Balanced Equation | back 39 A chemical equation in which the same number of each type of atom appears on both sides. |
front 40 Base | back 40 A substance with a pH greater than 7.0 that releases hydroxide ions in a water solution; for example, milk of magnesia. |
front 41 Behavior | back 41 An organism's actions or reactions to its environment. |
front 42 Beta Particle | back 42 An electron emitted from the nuclease of a radioactive atom. |
front 43 Bias | back 43 Anything that sways an experiment's results in a way that makes them inaccurate. |
front 44 Big Bang Theory | back 44 The idea that the universe began with an explosion of a dense, hot, compact mass under extreme pressure. |
front 45 Binary Fission | back 45 A method of reproduction in which a cell divides into two new cells. |
front 46 Biodegradable | back 46 Organic materials that naturally decompose. |
front 47 Biodiversity | back 47 A healthy variety of plant and animal species coexisting in an environment and making the environment more stable. |
front 48 Biogenesis | back 48 The principle that living things only come from living things. |
front 49 Biological Clock | back 49 An internal control of natural behavioral cycles. |
front 50 Biological Process | back 50 A fundamental property that is common to all living organisms. |
front 51 Biology | back 51 The study of all living things. |
front 52 Biomass | back 52 The total mass of the living organisms in a particular place. |
front 53 Black Hole | back 53 The collapsed leftovers of a supernova. |
front 54 Blue Star | back 54 A massive, hot star that uses up its hydrogen quickly, expands, and turs into a giant or supergiant |
front 55 Boiling Point | back 55 The temperature at which a liquid turns into a gas. |
front 56 Bosons | back 56 Force-carrying subatomic particles. |
front 57 Botany | back 57 The study of plants. |
front 58 Brain Stem | back 58 The part of the human brain that controls automatic functions such as breathing and heartbeat. |
front 59 Bronchi | back 59 The two tubes that lead from the trachea into each of the lungs. |
front 60 Bronchioles | back 60 Tubes branching off the bronchi in the lungs and ending in alveoli. |
front 61 Bud | back 61 The part of a plant where the new growth takes place. |
front 62 Calorie | back 62 A measure of energy. |
front 63 Camouflage | back 63 A coloring pattern that enables an animal to blend into their surroundings and not be seen by predators. |
front 64 Capillaries | back 64 Very small blood vessels. |
front 65 Carbohydrate | back 65 The main source of food energy. |
front 66 Carbon Cycle | back 66 A process that keeps the carbon on Earth in balance. |
front 67 Carbon-oxygen Cycle | back 67 The continuous circulation of carbon and oxygen through the biosphere primarily through the processes of photosynthesis, respiration, and decomposition. |
front 68 Carnivore | back 68 An animal that eats other animals. |
front 69 Carrying Capacity | back 69 The maximum population an ecosystem can support without losing resources. |
front 70 Cartilage | back 70 A tough, flexible material that covers bones and joints. |
front 71 Catalyst | back 71 A substance that provides a faster mechanism by which a reaction may take place. |
front 72 Cause | back 72 Something that makes something else (an effect) happen. |
front 73 Cause-and-Effect Relationship | back 73 Something that can make something else (a cause) happen results in another (an effect). |
front 74 Cell | back 74 The smallest unit of life that can exist independently and that makes up all living organisms. |
front 75 Cell Cycle | back 75 The process of division of a cell into new identical cells. |
front 76 Cell Membrane | back 76 The soft, flexible covering that holds a cell together and separates it from other cells. |
front 77 Cell Specialization | back 77 The process in which the cells of an organism develop in different shapes, structures, and functions. |
front 78 Cell Wall | back 78 A tough, flexible covering that surrounds the cell membrane of a plant cell. |
front 79 Cellular Respiration | back 79 The chemical process requiring oxygen by which living things convert food to energy. |
front 80 Cerebellum | back 80 The part of the brain , which controls movement, coordination, and balance; located below the cerebrum at the base of the skull. |
front 81 Cerebrum | back 81 The largest part of the human brain, which coordinates all higher functions such as perception, thinking, and conscious actually. |
front 82 Chain Reaction | back 82 A reaction in which nuclei are split apart in a controlled way, resulting in a great quantity of nuclear energy. |
front 83 Chemical Formula | back 83 A shorthand way of showing which elements are contained in a molecule. |
front 84 Chart | back 84 A visual representation of data. |
front 85 Chemical Bonding | back 85 The process though which atoms are combined. |
front 86 Chemical Change | back 86 A change that produces a new substance. |
front 87 Chemical Equation | back 87 A shorthand way of describing what happens in a chemical reaction. |
front 88 Chemical Reaction | back 88 The process in which two or more substances combine to form one or more substances. |
front 89 Chemical Weathering | back 89 Process that changes the composition of the rocks and occurs through chemical reactions. |
front 90 Chlorophyll | back 90 The green substance in a plant cell that is used to capture light energy. |
front 91 Chloroplast | back 91 An organelle in a plant cell that contains chlorophyll. |
front 92 Chromatin | back 92 The part of a cell's nucleus that contains genetic information. |
front 93 Chromosome | back 93 A structure in a cell that contains DNA. |
front 94 Circadian Clock | back 94 A biological clock that controls daily activity. |
front 95 Circular Argument | back 95 A form of faulty logic which a conclusion is supported by reasons that simply restate the conclusion. |
front 96 Circulatory System | back 96 the system, consisting of the heart, blood vessels, and the blood, that carries nutrients and oxygen to the body's tissues removes carbon dioxide and waste products. |
front 97 Climate | back 97 Average weather conditions in a particular region over a long period of time. |
front 98 Cloning | back 98 The process of creating a genetically identical replica of an organism. |
front 99 Closed Universe | back 99 The theory that the universe at some future time will begin to contract and collapse into its original state as a solar nebula. |
front 100 Coal | back 100 A solid fossil fuel. |
front 101 Codon | back 101 A combination of three bases. |
front 102 Coefficient | back 102 A number added to the reactants and the products to balance a chemical equation. |
front 103 Cold-Blooded | back 103 A classification of an organism that cannot control its own body temperature. |
front 104 Colloid | back 104 A mixture in which fine particles are spread out throughout a second substance; for example, foam. |
front 105 Collusion | back 105 When two or more moving objects run into one another. |
front 106 Comet | back 106 A small object made of dust and frozen gas that orbits in a predictable path around the sun. |
front 107 Commensalism | back 107 A relationship that benefits organism, while the other is neither harmed nor helped. |
front 108 Common Ancestor | back 108 An individual in a species history to which all individuals in that species can be traced. |
front 109 Compare | back 109 To identify how things are alike. |
front 110 Complete Metamorphosis | back 110 a type of metamorphosis that takes place in four stages. |
front 111 Complex Machine | back 111 Two or more simple machines put together. |
front 112 Composting | back 112 The use of natural biological processes to aid in the decomposition of organic materials. |
front 113 Compound | back 113 A group of molecules that each contain the atoms of two or more elements. |
front 114 Concentrated | back 114 When a solution contains a large amount of solute. |
front 115 Conclusion | back 115 A logical result or generalization. |
front 116 Condensation | back 116 The change of a of a gas into a liquid. |
front 117 Condense | back 117 To change from gas to a liquid; for example, from steam to water. |
front 118 Conduction | back 118 Transfer of heat through direct contact. |
front 119 Conductor | back 119 A substance through which electric current flows easily. |
front 120 Conservation | back 120 The controlled use and preservation of natural resources. |
front 121 Constancy | back 121 The tendency for things to remain unchanged. |
front 122 Constellation | back 122 A pattern of stars in the sky that humans have observed and named. |
front 123 Consumer | back 123 An organism that must eat other organisms to obtain energy. |
front 124 Contaminants | back 124 Substances that harm the environment. |
front 125 Context | back 125 The situation within which something is said or done. |
front 126 Continental Drift | back 126 The movements of continents. |
front 127 Contraction | back 127 A decrease in size of a substance due to its atoms moving closer together, often caused by a decrease in temperature. |
front 128 Contrast | back 128 To identify how things are different. |
front 129 Control Variable | back 129 A factor that is kept the same or constant during an experiment. |
front 130 Convection | back 130 The movement of heat through a liquid or gas. |
front 131 Convection Currents | back 131 Currents of molten rock the mantle that carry much of the heat to Earth's surface. |
front 132 Copernican Theory | back 132 The idea that the Sun is at the center of the solar system |
front 133 Core | back 133 The center of the Earth. |
front 134 Coriolis Effect | back 134 The apparent change in motion of wind and water on Earth's surface due to rotation. |
front 135 Covalent Bond | back 135 A bond in which electrons are shared by the bonded atoms of the molecule. |
front 136 Crest | back 136 The high point of a wave. |
front 137 Crust | back 137 The outermost layer of Earth. |
front 138 Crustal Plates | back 138 The exterior layer of Earth's crust (surface); also called tectonic plates |
front 139 Current | back 139 A large movement of water. |
front 140 Cytoplasm | back 140 In a cell, the jellylike matter that surrounds the nucleus and contains cell structures (called organelles) that carry out the cell's activities. |
front 141 Data | back 141 Information gathered during an experiment or investigation. |
front 142 Daughter Cells | back 142 The cells produced as a result of cell division, each identical to the parent cell. |
front 143 Decomposer | back 143 An organism that feed off the dead bodies of a once-living organism. |
front 144 Dendrite | back 144 A branching fiber on a nerve cell the receives messages from another nerve cell. |
front 145 Denitrification | back 145 The process by which certain bacteria in the soil change nitrates into gaseous nitrogen, returning it to the air. |
front 146 Density | back 146 A measure of mass in relation to volume. |
front 147 Dependent Variable | back 147 A factor is changed in response to the independent variable during an experiment. |
front 148 Diagram | back 148 A picture or an illustration that shows information. |
front 149 Diffraction | back 149 The process in which a waves spread out into a region behind or around a barrier. |
front 150 Diffusion | back 150 Movement of a substance from a region of higher concentration to a region of lower concentration. |
front 151 Digestion | back 151 The breaking down of food into nutrients that the body's cells can use. |
front 152 Digestive System | back 152 The system of the body that breaks down food into nutrients the body can use and expels leftover wastes. |
front 153 Dilute | back 153 A solution with the small amount of solute. |
front 154 Direct Current | back 154 Electric current that moves in one direction only. |
front 155 Dissolve | back 155 To become part of a solution. |
front 156 Distillation | back 156 A process for separating liquids that have different boiling points. |
front 157 DNA | back 157 The molecules that contains hereditary information and controls the activities of each cell; found in the chromosomes. |
front 158 Dominant | back 158 An allele for which the phenotype will always be present. |
front 159 Dominant Gene | back 159 One gene in a pair that determines the effect of the gene pair. |
front 160 Dominant Trait | back 160 A trait that will appear in an offspring if one parent contributes it; dominant traits suppress recessive traits. |
front 161 Double Blind | back 161 An investigation in which neither the researchers nor the patients know who is receiving placebos. |
front 162 Drag | back 162 The force slowing or stopping the movement of an object through a gas or liquid. |
front 163 Drawing Conclusions | back 163 Expressing unstated ideas that are logically connected to give information. |