| A | B |
|---|
| abiotic | nonliving parts of the environment |
| acid | a compound that releases hydrogen ions when a dissolved in water; a substance, such as vinegar, with a sour tasts. |
| acid rain | rain that is more acidic than normal |
| active transport | the process by which cells use energy to transport molecules through the cell membrane from areas of low concentration to areas of high concentration |
| adaptive value | any trait that helps an organism survive and reproduce under a given set of environmental conditions |
| agarose | a gel-like substance used in bacterial conditions |
| AIDS | (acquired immunodeficiency syndrome) the disease that results when the HIV virus attacks the human immune system |
| allergy | a condition in which a person's immune system is overly sensitive to environmental substances that are normally harmless |
| amino acid | any one of several building blocks of protein |
| antibody | a protein, produced by the immune system, that either attacks invading pathgens or marks them for killing |
| antigen | a molecule found on the outer surfaces of cells that the immune system recognizes as either part of the body or an outside invader |
| antihitamine | a substance that reduces the effects of histamines and the symptoms they cause |
| artificial selection | the process of breeding two organisms with desirable characteristics to produce offspring that have the advantages of both parents |
| asexual reproduction | a method of reproducion in which all the genes passed on to the offspring are from a singke individual or parent |
| assumption | something accepted as true that may or may not actually be true |
| ATP | (adenine triphosphate) a compound that stores energy in cells |
| autotroph | an organism that produces its own food; the source of energy for all other living things on Earth |
| bacterium | any one of many single-celled-organism without a distinct nucleus |
| balance | a tool that measures mass by comparing the unknown mass of an object with an object of known mass |
| base | a compound that produces hydroxide ions when dissolved in water |
| bias | a tendency to favor something; prejudice |
| biochemical process | a chemical process that occurs in a living thing |
| biodiversity | the variety of species in an area |
| biome | large groups of ecosystems, collectively; the biologically inhabited portions of Earth, including all of the water, land, and air in which organisms survive |
| biotechnology | the combinationof technology and biological sciences |
| biotic | the living parts of the environment |
| bond | the chemical link between atoms that hold molecules together |
| calibrate | to adjust the scale of a measurement tool |
| carnivore | an organism that surbives by eating animals |
| carrying capacity | the largest population of any single species that an area can support |
| catalyst | a substance that can speed up the rate of a chemical reaction without being changed or used up during the reaction |
| cell | the basic unit of structure and function that makes up all organisms |
| cell membrane | the thin boundary between the cell and its environment |
| cellular respiration | the process in which nutrients are broken apart, releasing the chemical energy stored in them |
| Celsius | a temperature scale based on 100 equal units, with ) as the freezing point of water and 100 as the boiling point of water |
| chloraplast | the green organelle that contains chlorophyll; where photosynthesis takes place |
| chromatography | a laboratory technique used to seperate mixtures of molecules |
| chromosome | a thick, threadlike structure that contains genetic information in the form of DNA |
| circulation | the flow of materials within a cell as well as between parts of a multicellualr organism |
| classify | to group things based upon their similarities |
| climax community | a relatively diverse and stable ecosystem that is the end result of succession |
| clone | an organism that is genetically identical to the organism from which it was produced |
| cloning | a technique wused to make identical organisms |
| community | a combination of all the different populations that live and interact in the same environment |
| competiton | the struggle between organisms for the same limited resources in a particular area |
| compound light microscope | a tool that uses more than one lens and a light source to magnify an object |
| conclusion | the deciision made about the outcome of an experiment; usually based on how well the actual result matches the predicted result |
| consumer | an organism that obtains its energy from producers |
| control | that group in an experiment in which everything-except the variable to be tested-is identical; the standard of comparison in an experiment |
| controlled experiment | an experiment in which all variables-except for the one being rested-are exactly the same |
| coverslip | a thin slice of glass that covers the specimen on a slide |
| cytoplasm | the jellylike substane that is between the cell membrane and the nucleus that contains specialized structures |
| data | the results of specific trials and tests completed during experiments |
| decomposer | decomposer an organism, generally a bacterium or fungus, that consumes dead organisms and organic waste |
| decomposition | the process whereby dead organisms, as well as the wastes produced by living organisms, are broken down into their raw materials and returned to the ecosystem |
| deforestation | forest destruction that results from human activity |
| dependent variable | the part of an experiment that is changed to test a hypothesis |
| depletion | a serious decline or reduction |
| detrimental | damaging; harmful |
| deviation | a change from normal circumstances |
| dichotomous key | a guide that compares pairs of observable traits to help the user identity an organism |
| differentiation | the process that transforms developing cells into specialized cells with different structures and functions |
| diffusion | the movement of molecules from areas of high concentration |
| digestion | the process that breaks down large food molecules that the organism can use |
| direct harvesting | the destruction of an organism or the removal of an organism from its habitat |
| disease | a condition, ohter than inhury, that prevents the body from working as it should |
| dissection | the act of cutting apart a dead organism to examine its internal structure |
| DNA | (deoxyribonucleic acid) the material found in all cells that contains genetic information about that organism |
| dynamic equilibrium | the constant small corrections that normally occur to keep an organism's internal environment within the limits needed for survival |
| ecological niche | the specific role played by an organism or a population of organims in the ecosystem |
| ecological succession | the process by which an existing community is replaced by another community |
| ecology | the study of how living things interact with one another and with their environment |
| ecosystem | all the living and nonliving things that interact in a specific area; a subdivision of the environment |
| egg | a sex cell produced by a female |
| electronic balance | a balance that measures mass automatically |
| electrophoresis | a tool that allows scientists to seperate mixture of molecules according to size |
| element | a substance consisting of only one kind of atom |
| embryo | an organism in the early stages of development (prior to birth) |
| endocrine glands | various hormone-producing glands that secrete substances directly into the blood or lymph |
| endoplasmic reticulum | an organelle that transports proteins and other materials from one part of the cell to another |
| energy flow | the movement of energy through an ecosystem |
| energy pyramid | a diagram showing how food energy moves through the ecosystem |
| environment | every living and nonliving thing that surrounds an orgainsm |
| environmental impact statement | a statement that includes an analysis of how a new project or technology might affect the environment |
| enzymes | proteins that speed up the rate of chemical reactions in living things |
| equilibrium | a state of balance and stability |
| estrogen | a hormone (produced by the ovaries) that controls female sexual development and the reproductive process |
| evidence | support for the idea that something is true |
| evolution | the process by which species have changed over time |
| excretion | the removal of all the wastes produced by the cels of the body |
| experiment | a series of trials or tests that are done to support or refute a hypothesis |
| expressed | the way that an unseen gene is seen in an organism as an actual physical trait |
| extinction | the dissapearance of all members of a species from Earth |
| Fallopian tubes | that part of the female reproductive system where the egg call is fertilized by the sperm cell |
| feedback mechanism | a cycle in which the output of a system either modifies or reinforces the first action taken by the system |
| fertilizatiion | the process that combines a sperm cell and an egg cell |
| fetus | the unborn, developing young of an animal during the later stages of development |
| finite | limited |
| flow of energy | the movement of energy through an ecosystem |
| food chain | a representation that identifies the specific feeding relationships among organisms |
| food web | a representation of many intrconnected food chains that shows the feeding relationships among producers, consumers, and decomposers |
| forceps | a tool used mainly during dissection to lift out small parts, to move structuresm and to pry parts open |
| fossil | the preserved remains of ancient organisms |
| fossil fuel | a fuel, such as coal and gas, that comes from the remains of organisms that lived millions of years ago |
| fossil record | a collection of fossils used to represent Earth's history |
| fungus | the kingdom of organisms that lived millions of years ago |
| gamete | an egg or sperm cell; a sex cell |
| gas exchange | the process of obtaining oxygen from the environment and releasing carbon dioxide |
| gene | a segment of DNA (on a chromosone) that contains the code for specific trait |
| gene expression | the result of activated genes |
| genetic engineering | a set of technologies that humans use to alter the genetic instructions of an organism by substituting DNA molecules |
| genetic recombination | the formation of a new combination of genes during sexual reproduction |
| genetic variation | the normal differences found among offspring |
| geologic time | Earth's history as revealed by layers of rock |
| global warming | a increase in Earth's average surface temperature caused by an increase in green house gases |
| glucose | a sugar that is a major source of energy for cells |
| graduated cylinder | a tool used to measure the volume of a liquid |
| greenhouse effect | the trapping of heat by gases in the atmosphere |
| greenhouse gas | an atmospheric gas that traps heat |
| growth | an increase in the size or number of cells |
| guard cells | specialized cells that control the opening and closing of the pores on the surface of a leaf |
| habitat | the place where an animal or plant lives |
| herbivore | an organism that eats only plants |
| heredity | the passing of traits from parent to offspring |
| heterotroph | organism that cannot make its own food; consumers |
| histamine | a chemical that is released as the immune system's reaction to an allergy |
| homeostasis | the ability of an organism to maintain a stable internal environment even when the external environment changes |
| hormone | a chemical produced in the endocrine glands |
| host | the organism in a parastic relationship that provides a home and/or food for the parasite |
| hot water bath | in the science laboratory; usually a large beaker of water heated on a hot plate; used to heat test tubes that contain a flammable liquid, such as alcohol |
| humerus | the long bone in the upper part of the arm |
| hypothesis | a statement that predicts a relationship between cause and effect in a way that can be tested |
| immune system | the body's primary defense against disease-causing pathogens |
| immunty | the body's ability to destroy pathogens before they cause disease |
| independent variable | a factor that might influence the dependent variable in an experiment |
| indicator | a substance that changes color when it encounters certain chemical conditions |
| industrialization | the process of converting an economy into one in which large-scale manufacturing is the primary economic base |
| inference | a conclusion or deduction based on observations |
| infinite | without limits or bounds |
| inorganic | a type of molecule that does not contain both carbon and hydrogen but can contain any other combination of elements |
| insulin | a hormone that prompts glucose to move from the blood into body cells, resulting in a lower glucose level in the blood |
| limiting factor | any factor in the environment that limits the size of a population |
| lipid | any one of a group of organic compounds that includes oils, fats, and waxes |
| magnification | the ability of a microscope to make an object appear larger |
| mass | a measure of the quantity of matter in an object |
| meiosis | the process that results in the production of sex cells (sperm and egg) |
| meniscus | the curved surface at the top of the column of liquid |
| metabolism | all the chemical reactions that occur within the cells of an organism |
| metric ruler | a tool used to measure the length of an object |
| microbe | any microscopic organism |
| micrometer | a unti of length equal to one millionth of a meter |
| microscope | a tool that uses a lens or a combination of lenses to magnify an object |
| mitosis | the process that divides the cell's nucleus into two, each with a complete set of genetic material from the parent cell |
| model | a representation used to explain or demonstrare a process or structure; also used to predict what might occur in a new situation |
| molecule | a particle in which two or more atoms combines to form a single unit; the smallest unit of a compound |
| muscular system | a body system comprised of tissue that contracts when it is stimulated; the combination of muscles that enables the body to move |
| mutation | any alteration in the seguence of DNA |
| natural selection | the process by which the organisms that are best adapted to a specific environment survive and produce more offspring than organisms that are not as well adapted |
| niche | the specific role played by an organism in its environment |
| nitrogen cycle | the movement of nitrogen from the atmosphere to the soil and organisms and then back to the atmosphere |
| nitrogen fixation | the process by which nitrogen forms compounds that can be used by living things |
| nonrenewable resource | any resource, such as fossil fuels and minerals, that cannot be replaced |
| nuclear fuel | an energy source that results from splitting atoms |
| nucleus | a large structure within a cell that controls the cell's metabolism and stores genetic information, including chromosomes and DNA |
| nucleic acids | a substance that provides the body with the materials and energy needed to carry out the basic life of cells |
| nutrient | a substance that provides the body with the materials and energy needed to carry out the basic life of cells |
| objective | on of the lenses of a microscope |
| observation | any information that is collected with any of the senses |
| ocular | the eyepiece lens of a microscope |
| opinion | ideas people have that may or may not be based in fact |
| optimum | the most favorable condition |
| organ | a body structure made of different kinds of tissues combined to perform a specific funtion |
| organ system | several organs that work together to perfrom a major function in the body |
| organelle | a sttucture within the cell that carries out a specific function |
| organic | term used to describe molecules that contain both hydrogen and carbon |
| organic compound | a compound that contains both hydrogen and carbon |
| ovary | the organ of the human female reproductive system that produces an egg cell, the female gamete |
| overproduction | the potential for a species to increase its numbers beyond the area's carrying capacity |
| oviduct | the part of the female reproductive system where the egg cell is fertilized by the sperm |
| oxygen-carbon dioxide cycle | the movement of oxygen and carbon dioxide between living things and the environmenrt |
| ozone shield | the layer of ozone gas in the upper atmosphere that protects Earth from some of the sun's rediation |
| pancreas | an endocrine organ that secrtes insulin |
| parasite | an organism that survives by living and feeding on other organisms |
| parastic relationship | an arrangment in which one organism lives in or on a host organism, deriving some or all of its nourishment from the hosy, to the host's detriment |
| pathogen | an organism that invades the body, causing disease |
| peer review | the process by which scientists carefully examine the work of other scientists to look for possible flaws in their experimental design or their interpretation of results |
| pH | a measure of whether a substance is acidic, neutral, or basic |
| photosynthesis | the process by which some organisms are able to capture light energy and use it to make food from carbon dioxide and water |
| pioneer species | the first organisms to become established in a new habitat |
| pipette | a laboratory tool that looks like a slender tube but works something like an eyedropper |
| placenta | the organ that enables nutrients and oxygen, to pass from the mother's blood to the fetus, and waste products to pass from the fetus to the mother's blood |
| plant | any complex, multicellular organism that obtains energy through photosynthesis and consists of cell wals and specialized tissues and organs |
| poaching | illegally capturing or killing an organism |
| pollution | a harmful change in the chemical makeup of the soil, water, or air |
| population | all the individual of a single species that live in a specific area |
| predator | an animal that hunts and kills other animals for food |
| predator-prey relationship | the connection between predators and prey that limits the growth of both populations |
| prey | an animal that is hunted and killed by predators |
| primary succession | the first group of communities that moves into a previously lifeless habitat |
| producer | an organism that makes its own food from light energy and inorganic materials |
| progesterone | a hormone associated with sexual development and the reproductive system |
| proportion | the relationship of one thing to another in terms of size, number, amount, or degree |
| protist | a single-celled organism with both its genetic materials and its organelles enclosed in membranes |
| quarantine | confined isolation |
| radius | one of the two long bones of the lower forearm |
| receptor molecule | certain protein molecules in the cell membrane that can receive chemical messages from other cells |
| recombination | the additional mixing of genetic material from a sperm and egg which results in a unique combination of genes |
| refute | to disprove |
| replicate | to copy |
| renewable resources | Earth's resources, such as our food supply and solar energy, which given time, can be replaced |
| research plan | the initial stage of an experiment that involves finding backroud information developing a hypothesis, and developing an experimental method for testing the hypothesis |
| respiration | the process by which the chemical bond energy stored in nutrients is released for use in cells |
| reproduction | the process by which organisms produce new organisms of the same type |
| ribosome | one of the tiny structures in the cell that is the site of protein production |
| rider | one of the devices that feeds on the bodies of dead organisms |
| scavenger | a carnivore that feeds on the bodies of dead organisms |
| science | a way of learning about the natural world and the knowledge gained through that process |
| scientific theory | a concept, which has been tested and confirmed in many different ways, that explains a wide variety of observations |
| secondary succession | a type of change that occurs when a disturbance empties an existing habitat without destroying the soil |
| selective breeding | the process of choosing a few organisms with desirable traits to serve as the parents of the next generation |
| sensor | a structure that reacts to stimuli by sending a nerve impulse to the brain |
| sex cell | an egg (female) or a sperm (male) |
| sexual reproduction | a method of reproduction that involves two parents to produce offspring that are genetically different from either parent |
| sibling | a brother or sister |
| simple sugar | the result of digested starches |
| skeletal system | the body system that contains the bones, provides shape and supports, and protects internal organs |
| smog | a kind of air pollution that results when certain pollutants react with sunlight |
| species | a group of organisms that share certain characteristics and can mate with one another, producing fertile offspring |
| sperm | the male sex cell |
| splice | to join two things together |
| stain | a chemical used to make cell structures more visible when veiwed under a microscope |
| steady state | the condition in which something remains relatively constant in spite of minor fluctuations |
| stereoscope | a microscope that uses two eyepieces; often used for dissections |
| stimulus | any change in the environment that causes an organism to react |
| stomata | a tiny pore found on the underside of most leaves |
| subunit | the section of a DNA molecule that contains a sugar, a phosphate, and a base |
| symbiotic | a kind of long-term association between members of different species in which at least one species benefits and neither species is harmed |
| synthesis | a life process that involves combining simple substances into more complex substances |
| tare button | a function on an electric balance that returns the mass reading to zero |
| technology | all of the practical scientific knowledge that has been used to meet human needs |
| template | the pattern for a new molecule |
| testes | the male reproductive organ that produces sperm and the hormone testosterone |
| testosterone | a hormone associated with male sexual develpment and reproduction |
| theory | an explanation, supported by many observations and/or experiments, that can be used to accurately explain related occurrences |
| thermal pollution | a kind of water pollution in which the temperate of the water increases |
| tissue | a group of specialized cells that perform a specific funtion |
| toxic | poisonous |
| trait | a characteristic that is passed from parent to offspring through the genes |
| trade-off | an exchange or agreement made to reach a compromise |
| traspiration | the process whereby plants absorb water through their roots and eliminate it through tiny pores on the undersides of their leaves |
| triple-beam balance | a tool, with a single pan and three bars calibrated in grams, used to measure mass |
| tumor | a clump of cells that develops when cancerous cells divide uncontrollably |
| ulna | one of the two long bones in the lower forearm |
| uterus | the organ, in female animals, where the embryo develops into a fetus |
| vaccine | a substance made of weakened, killed, or partial pathogens and desighned to protect the body from future invasions of that pathogen |
| vacuole | storage sacs within the cytoplasm of a cell that may contain either wastes or useful materials, such as water or food |
| vertebrate | an animal with a backbone |
| virus | a nonliving particle of protein and genetic material that reproduces by invading the cell of a living organism |
| volume | the space occupied by something |
| water cycle | the process by which water continuously moves from Earth's surface to the atmosphere and back |
| zygote | the cell that results from the joining of the egg and sperm |
