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AHSGE Science Vocabulary 1. Homeostasis- the ability of an organism or cell to maintain internal balance and stability by adjusting its physiological process. 2. Active transport- the movement of a substance across a biological membrane against it concentration or electrochemical gradient with the help of energy input and specific transport proteins. 3. Passive transport- the diffusion of a substance across a biological membrane 4. Osmosis- the movement of water across a selectively permeable membrane 5. Diffusion- the spontaneous tendency of a substance to move down its concentration gradient from a more concentrated to a less concentrated area 6. Exocytosis- the cellular secretion of macromolecules by the fusion of vesicles with the cell membrane 7. Endocytosis- the cellular uptake of macromolecules and particulate substances by localized regions of the cell membrane that surround the substance and pinch off to form an intracellular vesicle. 8. Mimicry- the resemblance of one organism to another or to an object in its surroundings for concealment and protection from predators. 9. Camouflage- the method or result of concealing by disguise or protective coloration such that the organism appears to be part of the natural surroundings. 10. Migration- the process of changing location periodically especially by moving seasonally from one region to another. 11. Hibernation- the process of passing winter in an inactive or dormant state 12. Abiotic factors- an environmental factor that is not associated with the activities of living organisms. 13. Acid rain- precipitation that has a pH below normal and has an unusually high concentration of sulfuric or nitric acids, often as a result of chemical pollution of the air from sources such as automobile exhausts and the burning of fossil fuels. 14. Adaptation (protective adaptation)- the process of becoming adapted to an environment; an anatomical , physiological, or behavioral change that improves a population’s ability to survive. 15. Adenine- one of the four nitrogen-containing bases found in DNA that pairs with thymine 16. Aerobic- describes a process that requires oxygen 17. Agar- a complex polysaccharide derived from a marine alga and used a a solidifying agent in culture media 18. Allele- one of the alternative forms of a gene that governs a characteristic, such as hair color 19. Amino acid- any one of 20 different organic molecules that contain a carboxyl and an amino group and that combines to form proteins 20. Ammonia- a small, very toxic molecule (NH3) produced by nitrogen fixation or as a metabolic waste product of protein and nucleic acid metabolism. 21. Amphibian- a vertebrate that, with some exceptions, lives in water as a larva and on land as an adult, breathes with lungs as an adult, has moist skin that contains mucus glands, and lacks scales and claws; examples are frogs, toads, salamanders, and caecilians 22. Anaerobic- describes a process that does not require oxygen 23. Angiosperms- a flowering plant that produces seeds within a fruit 24. Animalia- a kingdom of multicellular, eukaryotic, heterotrophs whose cells do not have cell walls. 25. Aquatic biomes- freshwater biome-lakes, ponds, rivers, and streams, strongly connected to terrestrial (land) habitats; marine biome- saltwater habitats (oceans) 26. Archaebgacteria- a classification kingdom made up of bacteria that lkive in extreme environments; differentiated from other prokaryotes by various important chemical differences 27. Asexual reproduction- reproduction that does not involve the union of gametes and in which a single parent produces offspring that are genetically identical to the parent. 28. Assymetry- irregular in shape; without symmetry 29. ATP (adenosinetriphosphate)- an organic molecule that acts as the main energy source for cell processes; composed of a nitrogenous base, a sugar, and three phosphate groups. 30. Autotroph- an organism that produces its own nutrients from inorganic substances or from the environment instead of consuming other organisms. 31. Bacteria- domain of unicellular prokaryotes that have cell walls containing peptidoglycans 32. Behavioral adaptation- the way an organism reacts to changes in its internal condition or external environment 33. Bilateral symmetry- a condition in which two equal halves of a body mirror each other 34. Binomial nomenclature- a system for giving each organism a two-word scientific name that consists of the genus name followed by the species name. 35. Biodiversity-the number and variety of organisms in a given area during a specific period of time 36. Biomes- a large region characterized by a specific type of climate and certain types of plant and animal communities 37. Biosphere- part of Earth in which life exists including land and water; air or atmosphere 38. Biotic factors- an environmental factor that is associated with or results from the activities of living organisms 39. Bromeliads- Spanish moss; nonvascular plant with no vascular tissues to conduct water and minerals 40. Budding- asexual reproduction in which a part of the parent organism pinches off and forms a new organism 41. Carbohydrates- any organic compound that is made of carbon, hydrogen, and oxygen and that provides nutrients to the cells of living things. 42. Carbon cycle-carbon atoms are passed from producers to herbivores to carnivores and then passed to top carnivores, which eventually die and decay which eventually puts carbon atoms back into the soil for producers to use. 43. Carbon dioxide- CO2- a by-product of cellular respiration and also the atmospheric gas necessary for photosynthesis 44. Catalyst- substance that speeds up the rate of a chemical reaction 45. Cell-in biology, the smallest unit that can perform all life processes; cells are covered by a membrane and have a nucleus and cytoplasm 46. Cell membrane-a phospholipids layer that covers a cell’ surface and acts a s a barrier between the inside of a cell and the cell’s environment 47. Cell wall-a rigid structure that surrounds the cell membrane and provides support to the cell 48. Cellular respiration- the process by which cells produce energy from carbohydrates; atmospheric oxygen combines with glucose to form water and carbon dioxide 49. Chemical defense- chemicals produced by plants to defend themselves against animals 50. Chloroplast- an organelle found in plant and algae cells where photosynthesis occurs 51. Chromosomes- in eukaryotic cells, one of the structures in the nucleus that are made up of DNA and protein; in a prokaryotic cell, the main ring of DNA 52. Cilia (cilium)- a hair-like structure arranged in tightly packed rows that projects from the surface of some cells 53. Classification- in order to study organisms, a system used to name and group organisms in a logical manner based on similarities 54. Clear-cutting- method of harvesting trees in which all of the trees are removed from a land area, as opposed to selective cutting 55. Codominance-a condition in which both alleles for a gene are fully expressed. 56. Cold-blooded (ectothermic)- describes the ability of an organism to maintain its body temperature by gaining heat from the environment 57. Color-blindness- inherited by multiple genes; red and green color blindness is Xlinked recessive; blue color blindness is autosomal dominant 58. Combustion-burning; puts carbon into the atmosphere 59. Commensalism-a relationship between two organisms in which one organism benefits and the other is unaffected 60. Communities- a group of species that live in the same habitat and interact with each other 61. Concentration gradient- a difference in the number of molecules of a substance across a distance 62. Condensation- process by which a gas changes to a liquid 63. Cone- in animals, a photoreceptor within the retina that can distinguish colors and is very sensitive to bright light; in plants, a seed-bearing structure 64. Conservation- process of sustaining biological diversity at all levels; making do with less; using materials and energy wisely 65. Consumers- an organism that eats other organisms or organic matter instead o fproducing its own nutrients or obtaining nutrients from inorganic sources 66. Contractile vacuole- a membranous sac that helps move excess water out of certain freshwater protests. 67. Cotyledons-the embryonic leaf of a seed 68. Crossing-over- the exchange of genetic material between homologous chromosomes during meiosis; can result in genetic recombination 69. Cross-pollination- in angiosperms, the transfer of pollen from an anther of a flower on one plant to the stigma of a flower on another plant of the same species. 70. Cystic fibrosis- a fatal genetic disorder in which excessive amounts of mucus are secreted, blocking intestinal and bronchial ducts and causing difficulty in breathing 71. –cyte – suffix meaning cell 72. Cytoplasm- the region of the cell within the membrane that includes the fluid, the cytoskeleton , and all of the organelles except the nucleus 73. Cytosine- one of the four nitrogen-containing bases found in DNA; it is complementary to guanine 74. Decomposers- an organism that feeds by breaking down organic matter from dead organisms; examples include bacteria and fungi 75. Decomposition- the process of organic substances being broken down into their elemental components and returned to the soil as nutrients 76. Deforestation- destruction of forests 77. Deletion- a deficiency in a chromosome resulting from the loss of a fragment through breakage; a mutational loss of one or more nucleotide pairs from a gene 78. Denitrification- conversion of nitrates to nitrogen gas 79. Density dependent limiting factors- variable affected by the number of organisms present in a given area; example food and water 80. Density independent limiting factors- a variable that affects a population regardless of the population density; such as climate, weather, and natural disasters 81. Dependent variable-in an experiment, the variable that is changed or determined by manipulation of one or more factors 82. Independent variable- the factor that is deliberately manipulated in an experiment 83. Desert-a biome that receives less than 10 inches of rainfall per year; occurs between 15o and 30o north and south latitude 84. Dichotomous key- series of paired statements that describes physical characteristics of different organisms; used to identify organisms 85. Dicots- angiosperms who seed have two cotyledons (seed leaves) 86. Dihybrid cross- a Punnett square in which two factors (traits) are considered; the Punnett square will have 16 boxes 87. Diploid (2n)- term used to refer to a cell that contains both sets of homologous chromosomes 88. Species diversity- number of different species in the biosphere 89. Deoxyribonucleic acid (DNA)- nucleic acid that contains the sugar deoxyribose 90. Dominant allele- the allele that is always expressed in a pair of alleles 91. Down syndrome- also called Trisomy 21; an extra copy of a chromosome on the 21st pair of chromosomes; autosomal dominant 92. Dynamic equilibrium- refers to a condition in which the parts of a system are in continuous motion, but they move in opposing directions at equal rates so that the system as a whole does not change. 93. Ecological succession- the replacement of one type of community by another at a single location over a period of time. 94. Ecosystem- a community of organisms and their abiotic environment 95. Egg- the female gamete 96. Embryo- an organism in an early stage of development of plants and animals; in humans, a developing individual is referred to as an embryo from the second through the eighth week of pregnancy. 97. Endoskeleton- a structural support located inside the body of an animal. 98. Energy pyramid- a triangular diagram that show an ecosystem’s loss of energythrough the ecosystem’s food chain; each row in the pyramid represent a trophic (feeding) level in an ecosystem, and the area of the row represents food chain (the pathway of energy transfer through various stages as a result of the feeding patterns of a series of organisms. 99. Enzymes- a type of protein that speeds up metabolic reactions in plant and animals without being permanently changed or destroyed. 100. Estuary- wetlands formed where rivers meet the ocean 101. Eubacteria- the classification kingdom that contains all prokaryotes except archeabacteria. 102. Eukaryotic cell (eukaryote)- an organism made up of cells that have a nucleus enclosed by a membrane, multiple chromosomes, and a mitotic cycle; includes animals, plants, fungi but not bacteria and cyanobacteria 103. Evaporation- process by which water changes from liquid into atmospheric gas. 104. Exoskeleton- a hard, external supporting structure that develops from the ectoderm. 105. Binary fission- type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells. 106. Flagella (flagellum)- a long, hair-like structure that grows out of a cell and enables the cell to move. 107. Food chain- the pathway of energy transfer through various stages as a result of the feeding patterns of a series of organisms. 108. Food web- a diagram that shows the feeding relationships between organisms in an ecosystem. 109. Fossil fuels- organic substance such as coal, oil, and natural gas, found underground in deposits formed from the remains of organisms that lived millions of years ago. 110. Fruit- wall of tissue surrounding an angiosperm seed. 111. Fungi- kingdom composed of heterotrophs; many obtain energy and nutrients from dead organic matter. 112. Genes- a segment of DNA that is located in a chromosome and codes for a specific heredity trait. 113. Genetic code- the rule that describes how a sequence of three consecutive nucleotides (triplets) that correspond to specific amino acids, specifies the amino acid sequence of a protein. 114. Genetic variation- different combinations of genes, which in turn produces various phenotypes. 115. Genus- the level of classification that comes after family and that contains similar species. 116. Glacial lake- a lake formed by the melting of glacial ice 117. Glucose- product of photosynthesis; food source for plants; heterotrophs take in glucose by eating foods and it is broken down by cellular respiration. 118. Golgi body (apparatus)- cell organelle that helps make and package materials to be transported out of the cell. 119. Grassland- found in moderate climates half-way between the equator and the poles; prairies are grasslands; highly productive when converted to agriculture; roots penetrate deep into the soil; grazing herds dominated this biome 120. Groundwater- water that is beneath the Earth’s surface. 121. Guanine- one of the four nitrogen containing bases found in DNA and RNA; complementary to cytosine. 122. Gymnosperm- a woody vascular seed plant whose seeds are not enclosed by an ovary or fruit. 123. Habitat- the place where an organism usually lives. 124. Haploid- describes a cell, nucleus, or organism that has only one set of unpaired chromosomes. 125. Hemophilia- a human genetic disease caused by a sex-linked recessive allele resulting in the absence of one or more blood-clotting proteins; characterized by excessive bleeding following an injury. 126. Heterotrophs- an organism that obtains organic food milecules by eating other organisms or their by products and that cannot synthesize organic compound from inorganic compounds 127. Heterozygous- describes an individual that has two different alleles for a trait; Tt (where T= tall phenotype and t= short phenotypes in pea plants) 128. Homozygous- describes an individual that has identical alleles for a train on both homologous chromosomes (TT or tt) 129. Hypertonic- describes a solution whose solute concentration is higher than the solute concentration inside a cell. 130. Hyptonic - when comparing two solutions, the solution with the lesser concentration of solutes 131. Incomplete Dominance – situation where one allele is not completely dominant over another 132. Infiltration- to permeate or enter 133. Insertion – a mutation involving the addition of one or more nucleotide pairs in a gene 134. Interdependence – organisms living and depending on each other in an environment. 135. Inversion – Change in chromosome structure in which a segment of a chromosome is turned around 180°; this reversed sequence of genes can lead to altered gene activity and abnormalities. 136. Invertebrates – animal that does not have a backbone 137. Isotonic – when the concentration of two solutions is the same 138. Lichen – symbiotic association between a fungus and a photosynthetic organism 139. Lipids – macromolecule made mainly from carbon and hydrogen atoms; includes fats, oils, and waxes 140. Locomotion – ability to move 141. Mammals - endothermic vertebrae characterized especially by the presence of hair and mammary glands. 142. Mass – amount of matter in an object 143. Meiosis – type of nuclear division that occurs as part of sexual reproduction, in which the daughter cells receive the haploid number of chromosomes in varied combinations 144. Mendel’s Laws – Law of Segregation-two alleles for a trait separate when the gametes are formed; Law of Independent Assortment- states that the alleles for different genes separate independently of one another during gamete formation. 145. Metabolism – all of the chemical reactions that occur in a cell during growth and repair 146. Mitochondrion – membrane-bounded organelle in which ATP molecules are produced during the process of cellular respiration 147. Mitosis – process in which a parent nucleus produces two daughter nuclei, each having the same number and kinds of chromosomes as the parent nucleus 148. Monera – in the previous five-kingdom, the kingdom that included the Archaebacteria and Eubacteria. 149. Monocots – angiosperm whose seeds have one cotyledon 150. Monohybrid Cross - cross between parents differ by one trait 151. Multicellular – organism composed of many cells; usually has organized tissues, organs, and organ systems 152. Multiple Alleles – three or more alleles of the same gene 153. Mutagens – a chemical or physical agent that interacts with DNA and causes a mutation. 154. Mutation- a change in the DNA sequence that affects genetic information. 155. Mutualism- symbiotic relationship in which both species benefit from the relationship; ants and aphids- ants take care of the aphids and the aphids produce a sweet substance the ants use for food 156. Native species- as opposed to exotic species is one that is original to a particular region. 157. Natural disasters- mud slides, earthquakes, volcanic eruptions, tsunamis, tornados, floods, forest fires, hurricanes 158. Nitrogen cycle- the natural process by which nitrogen, either from the atmosphere or from decomposed organic material, is converted by soil bacteria to compounds that can be assimilated by plants. This incorporated nitrogen is then taken in by other organisms and subsequently released, acted on by bacteria, and made available again to the nonliving environment. 159. Nitrogen oxide- a gas produced by many types of cells 160. Non-native species (Invasive)- a species, often introduced by humans, that takes hold outside its native range. 161. Nonvascular plants- the three groups of plants (liverwort, hornworts and mosses) that lack specialized conducting tissues and true roots, stems, and leaves. 162. Nucleic acids- an organic compound, either RNA or DNA whose molecules are made of one or two chains of nucleotides and carry genetic information 163. Nucleolus- small, dense region within most nuclei (plural for nucleus) in which the assembly of proteins begins. 164. Nucleus- in a eukaryotic cell, a membrane-bound organelle that contains the cell’s DNA and that has a role in processes such as growth, metabolism and reproduction. 165. Offspring- the product of reproductive processes in animals or plants 166. Organ systems- one of the levels of organization with in living organisms; made of organs and all organ systems make up the organism. 167. Organelles- one of the small bodies that are found in the cytoplasm of a cell and that are specialized to perform a specific function. 168. Organism- any living thing 169. Organs- a collection of tissues that carry out a specialized function of the body 170. Ovaries- in plants, a flower structure that contains one or more ovules from which female gametophytes are produces; in animals, the female gonad that produces eggs 171. Oxygen cycle- the cycle whereby atmospheric oxygen is converted to carbon dioxide in animal respiration and regenerated by green plants in photosynthesis 172. Ozone- O3; in the upper atmosphere; block the ultraviolet (UV) radiation of the sun 173. Parasite- a type of symbiont that lives in or on another organism. 174. Parasitism- a symbiotic relationship in which one organism lives in or on another organism (the host) and consequently harms it. 175. Pedigree- chart that shows the relationship within a family. 176. Peptidoglycan- a polymer that is composed of polysaccharide and peptide chains and is found especially in bacterial cell walls. 177. Permafrost- a layer of permanently frozen subsoil in the tundra. 178. Permeable- having pores or openings that allow gases or liquids to pass through. 179. Impermeable- not permitting passage (as a gas or liquid) through a substance. 180. Phenotype- physical characteristics of an organism. 181. Phenylketonuria (PKU)- an inherited metabolic disorder caused by an enzyme deficiency resulting in accumulation of phenylalanine and its metabolites in the blood causing usually severe mental retardation and seizures unless phenylalanine is restricted from the diet beginning at birth 182. Phosphorus- a nonmetallic element of the nitrogen family that occurs widely especially as phosphates. 183. Photosynthesis- process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches. 184. Pistil- the stigma, style and ovary of a plant; female portion of a plant 185. Plankton- tiny, free-floating organisms that occur in aquatic environments. 186. Plantae- kingdom of multicellular photosynthetic autotrophs that have cell walls containing cellulose. 187. Pollination- transfer of pollen from the male reproductive structure to the female reproductive structure of a plant. 188. Populations- group of individuals of the same species that live in the same area. 189. Precipitation- a deposit on the earth of hail, mist, rain, sleet, or snow ; the quantity of water deposited 190. Predation- interaction in which one organism captures and feeds on another organism. 191. Predator- one that preys, destroys, or devours 192. Prey- an animal taken by a predator as food 193. Producers- an organism that can capture energy from sunlight or chemicals and use it to produce food from inorganic compounds; also called autotrophs 194. Product- element or compound that is produced by a chemical reaction 195. Prokaryote- unicellular organism lacking a nucleus 196. Propagation (vegetative propagation)- growing plants from seeds or other vegetative parts 197. Protein synthesis- process of making proteins by using DNA and mRNA and takes place at the ribosome 198. Proteins- a macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair and to make up enzymes 199. Protista- kingdom composed of eukaryotes that are not classifies as plants, animals, or a fungus 200. Pseudopodia (pseudopod)- temporary projection of cytoplasm, or a “false foot,” used by some protests for feeding or movement; amoebas use pseudopodia to move 201. Punnett Square- diagram showing the gene combinations that might result from a genetic cross 202. Radial symmetry- body plan in which body parts repeat around the center of the body; characteristic of sea anemones and sea stars (echinoderms) 203. Rainforest- a tropical woodland with an annual rainfall of at least 100 inches (254 centimeters) and marked by lofty broad-leaved evergreen trees forming a continuous canopy —also called tropical rain forest 204. Reactant- element or compound that enters into a chemical reaction 205. Recessive allele- the allele that is masked by the dominant allele; only expressed when each allele inherited from the parents is recessive; represented by two lowercase letters (tt) 206. Recombinant DNA- DNA produced from combining DNA from different sources 207. Regeneration- in sea stars, the ability to regrow a missing arm, as long as a part of the central disk is present 208. Replication- copying process by which a cell duplicates its DNA 209. Reproduction- the process by which plants and animals give rise to offspring and which fundamentally consists of the segregation of a portion of the parental body by a sexual or an asexual process and its subsequent growth and differentiation into a new individual 210. Reptiles- any vertebrate that has dry scaly skin, lungs, and terrestrial eggs (eggs laid on land) with several protective membranes (the amniotic egg) 211. Ribosomal RNA- rRNA- type of RNA that makes up the major part of the ribosome 212. Ribosome- small particle in the cell on which proteins are assembled; made of RNA and proteins 213. Ribonucleic acid (RNA)- single-stranded nucleic acid that contains the sugar ribose. 214. Roots- underground organ in plants that absorbs water and minerals; fibrous root-part of a root system in which roots branch to such an extent that no single root grows larger than the rest (grasses have fibrous roots); taproot- primary root found in some plants that grows longer and thicker than other roots (carrots are taproots) 215. Rough Endoplasmic Reticulum- internal membrane system in cells in which lipid components of the cell membrane are assembled and some proteins are modifies; it is called rough ER because ribosomes are attached to the surface of the membrane 216. Seed- embryo of a living plant that is encased in a protective covering and surrounded by a food supply 217. Self-pollination- the pollen (containing the sperm) of a plant fertilizes the egg of the same plant; the offspring produced from self-pollination is genetically identical copy of the parent; self-pollination does not increase genetic diversity 218. Semi-arid- characterized by light rainfall; having about 10 to 20 inches of annual rainfall 219. Arid- excessively dry; not having enough rainfall to support agriculture 220. Semi-permeable membrane (selectively)- a membrane that allows some substances to cross and prevents other substance from crossing 221. Sex-linked trait- a trait that is determined by agene found on one of the sex chromosomes such as the X chromosome or the Y chromosome in humans 222. Sexual reproduction- reproduction in which gametes from two parents unite 223. Sickle Cell Anemia- a recessive genetic disorder caused by a mutated allele that produces a defective form of the protein hemoglobin 224. Smooth Endoplasmic Reticulum- same definition as rough ER except smooth ER does not have ribosomes attached to the membrane 225. Solute- substance that is dissolved in a solvent to make a solution 226. Solution- mixture of two or more substances in which the molecules of the substances are evenly distributed 227. Solvent- substance in which a solute is dissolved to form a solution 228. Species- group of similar organisms that can breed and produce fertile offspring 229. Sperm- the male gamete (sex cell) 230. Spontaneous generation- hypothesis stating that life could arise from nonliving matter; this hypothesis has been disproven 231. Spores- a reproductive cell or multicellular structure that is resistant to environmental conditions and that can develop into an adult without fusion with another cell; haploid reproductive cell 232. Stamen- the male reproductive structure of a flower that produces pollen and consists of an anther at the tip of a filament 233. Stomata (stoma, singular form)- many openings in a leaf or a stem of a plant that enable gas exchange to occur 234. Succession- the replacement of a community by another at a single location over a period of time 235. Succulents- plants that have fleshy tissue that hold moisture; cacti are examples of succulents 236. Surface runoff237. Symbiotic- a relationship in which two different organisms live in close association with each other 238. Body symmetry- the property of being symmetrical ; especially : correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or median plane or about a center or axis; organisms can have radial or bilateral symmetry; other organisms may be asymmetrical (no symmetry) 239. Taiga (Coniferous forest)- biome in which the winters are cold but summer are mild enough to allow the ground to thaw 240. Taxonomy- the science of describing, naming, and classifying organisms; the taxonomic grouping are kingdom, phylum, class, order, family genus, species 241. Tay-Sachs Disease- a recessive genetic disorder that occurs in early childhood; causes deterioration of the central nervous system and death; caused by a defective form of a brain enzyme 242. Deciduous forests- relatively mild climate and plentiful rain to promote the grow of the forest; predominant trees are those that shed their leaves in the fall; warm summers, cold winters and annual rainfall of 30 to 100 inches; commons animals include deer, bears, beavers, and raccoons 243. Terrestrial biomes- biomes that are found on land 244. Testes- the primary male reproductive organ, which produce sperm cells and testosterone 245. Thymine- one of the four nitrogen-containing bases found only in DNA; it is complementary to adenine 246. Tissues- a group of similar cells that perform a common function 247. Toxicity- containing or being poisonous material especially when capable of causing death or serious debilitation 248. Transcription- the process of forming a nucleic acid by using another molecule as a template; particularly the process of synthesizing RNA by using one strand of a DNA molecule as a template 249. Translation- the portion of protein synthesis that takes place at ribosomes and that uses the codons in mRNA molecules to specify the sequence of amino acids in polypeptide chains 250. Transpiration- the process by which plants release water vapor into the air through stomata; also the release of water vapor into the air by other organisms 251. Trophic levels- one of the steps in a food chain or food pyramid; examples include producers, and primary, secondary , and tertiary consumers 252. Tundra- characterized by a layer of permafrost; long, cold, dark winters; low precipitation; musk ox, Arctic foxes, caribou, and small rodents are characteristic animals; average temperature is -25oC to 5oC 253. Turgor pressure- also called turgidity, is the main pressure of the cell contents against the cell wall in plant cells. Turgid plant cells contain more water than flaccid cells and exert a greater osmotic pressure on its cell walls; a force exerted outward on a plant cell wall by the water contained in the cell. This force gives the plant rigidity, and may help to keep it erect. Turgor can result in the bursting of a cell. 254. Unicellular- composed of only one cell 255. Uracil- one of the four nitrogen bases that combines with sugar and a phosphate group to form a nucleotide subunit of RNA; uracil is complementary to adenine and found only in RNA 256. Vacuole- cell organelle that stores materials such as water, salts, proteins, and carbohydrates 257. Variation (within species)- divergence in the structural or functional characteristics of an organism from the species or population norm or average; something (as an individual or group) that exhibits variation 258. Vascular bundles- plant stem structure that contains xylem and phloem tissue 259. Vascular plants- plants that contain vascular tissues to transport water, minerals and nutrients throughout the plant; contain xylem and phloem 260. Venation- the arrangement of the veins in a leaf; net venation looks like a road map (oak and maple leaves); parallel venation pattern the veins run parallel to each other (Dogwood leaf) 261. Vertebrates- animal with a vertebral column or a backbone 262. Vesicle- a small cavity or sac that contains material in a eukaryotic cell; forms when part of the cell membrane surrounds the materials to be taken into the cell or transported within the cell 263. Volume- amount of space occupied by an object 264. Warm-blooded (endothermic)- describes the ability of an organism to maintain body temperature by producing heat internally; mammals are endothermic 265. Water-cycle- the sequence of conditions through which water passes from vapor in the atmosphere through precipitation upon land or water surfaces and ultimately back into the atmosphere as a result of evaporation and transpiration 266. Wetlands- ecosystem in which water either covers the soil or is present at or near the surface of the soil for at least part of the year Equation for photosynthesis…….takes place in the chloroplast in plants LIGHT 6CO2 + 6 H2O -------> C6H12O6 + 6O2 (Reactants) (Products) Equation for Respiration………takes place in the mitochondria in plants and animals C6H12O6 + 6O2 -------> (Reactants) 6CO2 + 6 H2O (Products) Lemonade is a solution. Water is the solvent. Sugar and lemon juice are the solutes. Ten Percent Rule: Each level on an energy pyramid only has 10% of the energy available from the level below it. Tertiary Consumer 0.1% energy Secondary Consumers Carnivores 1 % of energy available Primary Consumers Herbivores 10% of energy is available Producers/autotrophs Use 100% of energy form the sun to produce food Hawk (quaternary consumer/carnivore) Snake (tertiary consumer/carnivore) Robin (secondary consumer/carnivore) Insects (primary consumer/herbivore) Grass (producer)