R74 McDougal Littell Science Grade 6

Aabiotic factors, 496, 496, 497–499, 516, 524

as limiting factors, 550, 551spread of pollution by, 580, 580, 601–603, 602,629, 630

acceleration, 754accuracy, 20, 20, 32, 32, R22, R22 acid rain, 578, 578, 580, 630, 672actinides, 769 active transport, 241–244, 242, 242, 243, 248adaptation, FL29, 290, 344, 364, 429. See also

specialization.of arthropods, 433, 435, 436, 438of birds, 463, 464–466, 467, 468, 470, 470 and body temperature, 460–461, 464–465change in behavior, 336, 349, 352–354, 352, 353,354, 428, 438, 461, 465–466, 541

change in physiology, 242, 288, 289–290, 336, 336,343–344, 349–352, 351, 455, 458, 464

change in structure, 336, 337, 343–344, 351, 351,352, 382, 384, 415–416, 418–419, 418, 426, 429,430, 433, 435, 438, 448–449, 451, 458, 465–466,467, 472

of cnidarians, 418–419of echinoderms, 429, 429 of fish, 448–449, 451hibernation, 289, 354, 474of mammals, 472, 475–476of mollusks, 426, 427, 428–429, 429, 430of mosses and ferns, 382–386of plants, 343–344, 380, 382, 384, 388, 392, 435, 485protective coloration, 336, 336, 337, 428, 435reproductive success and, 336, 338–339, 338, 339,359, 385, 386, 388, 392, 436, 459, 485, 537

of reptiles, 458, 461seeds as, 388–389, 389

aeolipile, 137aerosol sprays, chlorofluorocarbons in, 634, 635Africa, 187, 601–603, 721agriculture. See farming.air

as abiotic factor, 496absorption and reflection of light, 618–619density of, 612, 621, 622, 623, 638, 646, 646 dust and, 601–603gases in, 613, 613, 630as need of living things, 192, 611saturation of, 660

air masses, 681, 681–684, 708, 708 continental polar, 682, 682 continental tropical, 682, 682

maritime polar, 682, 682 maritime tropical, 682, 682 movement of, 683, 688, 688 North American, 682 pressure systems and, 686–687, 686, 687 thunderstorms and, 695, 695 weather fronts, 684, 685

air movementair masses and weather, 681–684, 685, 686–687, 686, 687

air pressure and, 647, 649–650, 650, 652, 653, 654, 656, 656

cloud formation and, 662Coriolis effect on, 651, 651 jet streams, 654, 654 severe storms and, 693–698, 695, 696, 697, 698 uneven heating and, 648–649, 655–656, 656 wind, 601–603, 629, 630, 649–652, 653, 654–657wind belts, 652, 653

airplanes, collection of weather data by, 701, 701 air pollution, 43, 577, 629, 641, 672

acid rain from, 578, 578 attempts to reduce, 117, 590, 591, 631changes in climate and, 734–735effects of, 631global warming and, 633–664, 633 greenhouse gases as, 632–634, 632, 635 from human activities, 573, 578, 632 movement of, 580, 580, 601–603, 629from natural events, 578, 601–603, 734–735, 735 and ozone layer, 634–635, 635 particulate, 630–631, 636–637, 734–735, 735 precipitation and, 672reducing, 634types of, 630, 641

air pressure, 645, 645–648, 646, 652, 674air movement and, 647, 649–650, 650, 652, 653,654, 656, 656

high-pressure system, 686illustrated by isobars, 703, 703 low-pressure systems, 686–687, 686, 687, 689–693, 690, 691, 708

measurement of, 648, 648, 712station symbol for, 766, 766

air quality, 573, 578, 578, 580, 580, 601–603pollution, 629, 630–635, 632, 635, 641, 672

alcoholic fermentation, 234–235algae, 185, 277, 279, 279, 282, 382–383, 383

carbon cycle and, 504energy cycle and, 509and fungi, 360–361, 360 oxygen level in water and, 550red tide and, 184–187, 184–187

IndexPage numbers for definitions are printed in bold type.Page numbers for illustrations, maps, and charts are printed in italic type.

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algae bloom, 185algebraic equations, 628al-Khazini, 137alligators, 294, 295alternative energy sources, 44altitude, 612, 638

air density and, 612, 621, 622, 623, 646, 646 air pressure and, 646cloud formation and, 662density of air and, 621effect on boiling point, 94effect on precipitation, 719temperature and, 621, 622, 623, 719, 721, 721

altocumulus clouds, 663 altostratus clouds, 663 amino acids, 225, 225, 240amoeba, 256, 280amphibians, 454, 454, 456, 457, 478, 478

body temperature of, 460–461amplitude, of wave, 749analysis

critical, R8of data, 251, 251, 285, 285, 409, 409 of diagrams, 481, 481 of experiments, 107, 107 of graphics, 181, 181, 329, 329

angiosperm, 397, 397–398, 399, 400–404animal cells, 229, 229, 260, 260

active transport and, 241–244basic processes in, 229, 233 diffusion and, 238–240organelles of, 203, 203, 204, 205–206, 760, 761 osmosis and, 241sources of energy for, 224, 229–230viruses and, 260

Animalia (kingdom), 256, 317, 317, 318, 319, 320 characteristics of, 320, 758

animals, 344, 544abiotic factors and, 497, 497, 499adaptations to environment, 352–353, 352, 353 amphibians, 454–455, 456, 457, 460–461arthropods, 432–433, 434, 435–439behaviors of, 352–353, 352, 353 as biotic factor in ecosystems, 496birds, 463–466, 464, 465, 467, 468–469, 468,469, 470

body plans of, 417, 417, 421, 421 and body temperature, 289–291, 460–461, 464–465, 473–474

carbon cycle and, 614, 615 changes in environment and, 548, 553characteristics of, 413cnidarians, 414, 418–420, 419, 420 as consumers, 348–350, 364, 512, 513, 514dependence on environment, 531of desert and grassland biomes, 518, 519effects of global warming on, 740of estuaries, 295, 522in extreme climates, 288–289, 289–291, 290 fish, 448–452, 449, 450

of forest biomes, 294, 520of freshwater biomes, 295, 521as heterotrophs, 205invertebrates, 410, 410, 413–414, 439 (See alsoarthropods; cnidarians; echinoderms; mollusks;sponges; worms)mammals, 472–477mollusks, 426–429, 426, 427, 428, 429 nitrogen cycle and, 614, 615 patterns in living space of, 536patterns in time for, 537, 537 and plant reproduction, 401–403, 402, 544populations of, 549–550, 550, 551, 555preservation of species, 561, 563, 586 red tide and, 186relationships with other organisms, 348–349, 528, 528–529, 533, 540–545, 546, 547, 548, 550, 551,556, 559

reptiles, 454, 458–461, 458, 459, 460, 461, 462, 462 research involving, 753response to environment, 352–354, 352 of saltwater biomes, 522–523, 523 and seasonal changes, 354, 354 sources of food for, 224, 229–230, 348–349, 403specialization of cells of, 211, 333sponges, 414, 415–416, 415 of still water biomes, 295, 522structural organization of, 211–213, 212 in tundra and taiga biomes, 517vertebrates, 410, 478, 478 (See also amphibians; birds; fish; mammals; reptiles)

viruses and, 274water cycle and, 614, 615 worms, 422–423, 422, 423, 424–425

annelids, 422–423, 422, 423 Antarctica, ozone layer over, 635, 635, 715, 715 anther, 398, 399, 400, 400 aquatic biomes, 488–491, 488–489, 490, 521–524,

522, 523 pollution and, 579–580, 579, 580

aquifer, 490Aquifer Storage and Recovery (ASR), 490–491arachnids, 434, 438, 438 archaea, 264, 264, 322, 370

bacteria and, 209, 262, 264, 370characteristics of, 317, 317, 318, 319, 322, 755discovery of, 370helpful types, 267

Archaea, 256, 262, 319, 321characteristics of, 317, 317, 318, 319, 322, 755domain, 209, 317, 317, 755

Archimedean screw, 181, 181 Archimedes, 107, 137, 137 architecture, 672, 726Arctic National Wildlife Refuge (ANWR), 563, 563 Arctic Ocean, global warming and, 739Arctic wooly bear caterpillar, 290–291, 290 area, R43, R43argon, 613Aristotle, 136, 136

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R76 McDougal Littell Science Grade 6

arthropods, 414, 434, 440, 440 arachnids, 438, 438 characteristics of, 432–433, 433, 758 crustaceans, 437, 437 insects, 435–437, 435, 437 millipedes and centipedes, 439, 439

asexual reproduction, 258, 339, 364binary fission, 258, 258, 262of cnidarians, 420of ferns, 387of flowering plants, 398of fungi, 358of mosses, 386of segmented worms, 423of sponges, 416of unicellular organisms, 336

ash, in atmosphere, 578, 734, 734 Aspergillus sydowii, 602, 603assumptions, 7asthma, air pollution and, 631, 636astronomy, 137Atlantic Ocean, 689–690, 690

currents in, 723, 723 atmosphere, FL31, 611

absorption and reflection of radiation in, 624–627, 625, 627

air masses in, 681–683, 683, 684–697, 689–693air pressure, 645–648, 646, 648 characteristics of, 612, 612 clouds in, 624, 628, 658, 661, 661, 662–665, 662,663, 664, 665, 668, 674, 684

composition of, 613, 613, 713cycles in, 614, 615, 617, 620–621, 620 dust in, 601–603, 601, 602, 613, 616, 616, 630effect of human activities, 629–635, 630, 631, 632,633, 635

effect of natural events, 601–603, 616, 616, 630,632, 734–735, 735, 738

effect of natural processes, 601–603, 601, 602, 614, 615, 632, 634

effects on light, 624–626energy from the Sun in, 618–621, 623gases in, 613, 626, 626–627, 627, 630, 632–634, 632,714, 739–740

global warming of, 633–634, 633, 638, 739–740greenhouse effect, 626, 627, 627, 713, 737, 741Internet activity, 609jet streams in, 654, 654, 657, 683mass of, 612movement of energy, 620–621, 620 ozone layer of, 625, 625, 634–635, 635 pollution of, 577–578, 578 precipitation in, 635, 659, 668–670, 671 relative thickness of, 611sudden changes in, 616, 616 thermal layers of, 621, 622, 623time line for discovery about, 712–715water in, 659, 659, 660, 681–682weather formation in, 608, 684, 685, 686–687, 686,687, 688, 689–693, 694–698, 695, 697

wind and, 647, 649–652, 650, 651, 653, 654–656, 654, 655, 656

astronomical unit, 751atomic mass, 769 atomic model, 748, 748atomic number, 769 atomic symbol, 769 atomic theory of matter, 56atoms, FL33, 45, 56, 56–57, 224, 617, 617, 748

changes of state and, 90, 91, 92, 93, 94, 95chemical changes and, 86–88in compounds, 63, 64in elements, 62images of, 60, 60, 173matter and, 49in mixtures, 63, 64molecules and, 58motion of, 59, 59, 67, 69, 70, 71, 72, 73, 73 nanotechnology and, 172–173nuclear energy from, 113particles in nucleus, 139pressure and, 73, 73 pure and mixed, 74scanning tunneling microscope and, 60, 60 in solid, liquid, and gas phases, 68–73

Australia, 726automobiles. See cars.autotrophs, 342, 382autumn, 724auxin, 346average speed, 145axle. See wheel and axle.

Bbackbones, 447bacteria, 193, 207, 262, 262, 263, 282, 282, 323

archaea and, 209, 262, 264, 317, 317, 322chapter investigation of, 268–269characteristics of, 262–263, 317, 317, 318, 323discovery of, 369environments of, 264, 264 functions of, 265, 266, 504, 507, 507, 509, 511growth rates, 285 helpful and harmful types, 196, 265–267, 266, 267,270–271, 359, 361, 361, 511, 602–603

nitrogen-fixing, 266, 507, 507, 554, 614, 615 penicillin and, 361, 361 photosynthesis and, 265, 343reproduction of, 253, 258, 262spontaneous generation and, 196–197, 197 viruses and, 263, 270, 272, 273

Bacteria, 256, 262, 317, 317, 318, 319characteristics of, 755domain, 209, 317, 317

bacteriophage, 272, 273 balances, 50, 54 Bald Eagle Act of 1940, 561

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Index R77

balloonshot air, 713, 713 weather, 701, 701

barnacles, 437barometer, 648, 648, 712, 712 Bates, Henry Walter, 369beamed energy propulsion, 40beaver, 294bee dance, 331bees, 401–402, 401, 435, 544behavior, 352, 352, 353

to common stimuli, 428to find food, 542, 543growth and maintenance and, 353, 419, 435of insects, 435protection and, 536–537, 541reproduction and, 353, 435–436, 542responses to light, 346, 346 response to common stimuli, 192, 258response to environment, 192, 258, 345–347, 345,346, 347, 352–353, 353, 424–425, 461, 463, 466,468, 474

response to touch, 345social, 435

Belém, Brazil, average temperature in, 720Bhaskara, 137, 139bias, 27–28, R6bilateral symmetry, 421, 422binary fission, 258, 258, 262, 358binomial nomenclature, 308, 308–309, 309 biodiversity, FL29, 577. See also diversity.

benefits to humans, 582conservation efforts and, 589in Florida, 292–295, 292–295, 293, 294, 295 hotspots, 371, 371 human dependence upon, 582loss of habitats and, 295, 580–581, 580 pollution and, 577–580, 580, 592–593of prairie ecosystems, 486threats to, 295timeline of, 368–371

biomagnification, 515, 515 biomes, 516, 517, 524

deserts, 518, 519 freshwater, 521–522, 522 grassland, 519, 519 as level of organization of environment, 534, 535 saltwater, 522–523, 523 taiga, 517, 518, 518 temperate forest, 519–520, 520 tropical forests, 520, 520 tundra, 517, 517, 518

biosphere, FL31biotic factors, 496, 496, 497, 518, 524

of land biomes, 517, 518as limiting factor, 550, 550, 551

birds, 464, 465, 478, 478 beak adaptations, 470–471and body temperature, 464–465, 464 endangered and threatened, 489

environment, 463flight and, 465–466, 467, 468 migration of, 27–28, 295and plant reproduction, 559population patterns of, 541reproduction of, 468–469, 469

bird watching, 293birth rates, 550, 555bivalves, 427, 427, 429Bjerknes, Jacob, 714blizzard, 692block and tackle, 163Bloomington, Indiana, 724blubber, 474body fat, 474body plans, 417, 417, 421, 421, 422body temperature

of amphibians and reptiles, 460–461of birds, 464–465in extreme climates, 289–291of mammals, 473–474

boiling, 94, 94 boiling point, 94, 748bolt from the blue, 606–607, 607 bones, 451

of birds, 466, 467 of fish, 450 of mammals, 475

bony fish, 450, 451book lungs, 438Brady, Matthew, 560, 560 brainstorming, 9breezes, 655, 655, 765 brine shrimp, 24, 24 bristlecone pine tree, 376, 376 bromeliad plants, 602, 603brood parasitism, 547, 547 budding, 358buoyancy, 79, 137buoys, weather, 701, 701 Bush, George W., 563butterfly, 417, 421, 421

Ccactus, 380, 380, 498, 518, 532, 532, 533California, 738calm regions, 652Camp Blanding, Florida, 606Canary ocean currents, 723 cancer, ultraviolet radiation and, 625capsid, 271, 272, 282 carbohydrates, 224, 248, 248

glucose, 229photosynthesis of, 230production of, 342, 378

carbon, 224, 224, 225carbon cycle, 504, 504–505, 504, 524, 614, 615,

617,617 human impact on, 573

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R78 McDougal Littell Science Grade 6

carbon dioxide, 231 as abiotic factor, 496in the atmosphere, 613, 633, 714, 741in Biosphere 2, 237carbon cycle and, 504, 504–505, 504, 524, 614, 615,617, 617

cellular respiration and, 232, 233, 763, 763 diffusion of, 238, 239energy cycle and, 509fermentation and, 234forest fires and, 616as greenhouse gas, 626levels during ice ages, 737lungs and, 458as material needed by living things, FL29, 192, 259molecular structure of, 62, 617, 617 photosynthesis and, 230, 231, 342, 378, 762, 762 structure of, 617, 617

carbon dioxide-oxygen cycle, 229–230, 231, 232, 233,234–235, 234, 248, 378, 504, 504, 614, 615, 617

carbon monoxide, 58, 578, 630Caribbean Islands, 601–603Caribbean Sea, currents in, 723 carnivore, 349, 367 carpooling, 590carrying capacity, 529, 551, 568cars

efficiency of, 127, 127, 157electrically powered, 117, 127hybrids, 127 hydrogen powered, 43–45pollution from, 573, 578, 630powered by fossil fuel, 41, 117solar powered, 40, 40, 41, 128, 128 urbanization and, 573

Carson, Rachel, 562, 562 cartilage, 451cartilaginous fish, 450, 451Cassini space probe, 40, 40 catapult, 136, 136 cat family, 301, 301 cause-and-effect relationship, R5cell division, 195, 258, 258, 262, 336, 338–339, 339.

See also asexual reproduction.sexual reproduction and, 338, 338, 391

cell membranes, 202, 202, 203, 204, 248, 263, 761 active transport through, 242–243, 242, 243, 248diffusion and, 240, 240, 241, 246–247, 248function of, 257, 760 manufacture of, 205in protozoa, 280 structure of, 225, 227, 227

cells, FL11, FL29, 183, 188–189, 194, 216 active transport and, 241–244, 243 of animals, 199, 204, 205–206, 760, 761 basic processes in, 224–226, 229–230, 231, 232, 233, 234

as basic unit of life, 188, 193, 257classification of organisms by, 208diffusion and, 238–242, 239, 240

discovery of, 194diversity of, 202division of, 195, 336, 338–339, 339, 752elements of, 223eukaryotic cells, 202, 202, 203, 203, 204, 205–206, 317, 317

fertilization, 338, 338 functions of, 193, 216growth of, 205, 257Internet activity, 189maintenance, 205making slides of, 200meiosis, 338, 338 models of, 213, 214molecules in, 223, 224–226multicellular organisms, 193, 193, 202, 202,210–211, 216, 235, 320, 320, 333. See also animals;fungi; plants.

natural dyes and, 228organelles of, 202, 203, 203, 204, 205–206, 205, 206 of plants, 188–189, 204, 205–206, 224, 760, 761 prokaryotic cells, 202, 202, 209, 262–263, 263, 317reproduction of, 195size and shape of, 244–245, 245 slides of, 200space suits and, 215, 215 specialization of, 208unicellular organisms, 193, 193, 199, 199, 202, 208–209, 333. See also archaea; bacteria; protists.

and viruses, 273 cell theory, 195–196cellular respiration, 232, 233, 234, 236, 248, 248, 336,

343, 351, 763, 763 cellulose, 224cell walls, 203, 203, 204, 263, 320, 761

in algae, 279, 279 of bacteria, 263, 323function of, 760 of plants, 376of prokaryotes, 209structure of, 224

Celsius scale, 15, 15 centipedes, 439central vacuole, 204, 206, 206 cephalopods, 428, 429CERP, 490–491CFCs. See chlorofluorocarbon.change of state, 90–97, 92, 93, 94, 95 Chapter Investigations

bacteria, 268–269bird beak adaptations, 470–471cleaning oil spills, 592–593coin game, 12–13design a machine, 176–177diffusion, 246–247energy conversions, 124–125estimating populations, 538–539freezing point, 96–97growing seeds, 394–395making a field guide, 324–325

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Index R79

mass and volume, 54–55microclimates, 732–733observing particulates, 636–637plant and animal cells, 203–204relative humidity, 666–667soil samples, 500–501using a microscope, 198–199weather station design, 706–707worm behavior, 424–425yeast cells, 362–363

charge, positive and negative, 748, 749charged particles, 748, 749

electrons, 45, 748ion engines and, 39ions, 45, 171, 749lightning and, 605polar molecules, 226–227, 226, 240protons, 45, 748

chemical bonds, 45, 224cellular respiration and, 763, 763

chemical changes, 86, 86–88, 86, 88, 104Internet activity, 79

chemical energy, 113, 113, 116, 116, 229, 230change in form, 118

conversions to and from, 120, 124–125in fossil fuels, 117life processes and, FL29, 341–342, 508–511photosynthesis and, 382storage of in starch, 343

chemical factors, 497, 498–499chemical properties, 86, 104

changes in, 86–88potential energy and, 115, 116, 116

chemical reactions, 224, 630, 634chemicals

as biotic factors, 497as pollutants, 570, 579–580, 580, 585, 586, 634, 715

chemistry, FL32chemosynthesis, 509cherry trees, 399 chitin, 433Chlamydomonas, 279, 279 chlorine gas, 634chlorofluorocarbon, 634, 635chlorophyll, 230, 231, 378

in algae, 279, 279 in bacteria, 265photosynthesis and, 762, 762

chloroplasts, 204, 205, 205, 219, 378, 379, 761 in algae, 279, 279 function of, 760, 762 photosynthesis and, 230, 230, 231

cicadas, 433, 537, 537 cilia, 210, 210, 280, 280 circulation cells, 652, 653 circulatory system, 335

of arthropods, 433of crustaceans, 437of reptiles, 335, 458of segmented worms, 423

cirrocumulus clouds, 663 cirrostratus clouds, 663 cirrus clouds, 662, 662, 663 clams, 426clapper rails, 295class, 310, 311, 312classification, 300, 326, 368

of archaea, 264, 264, 755of bacteria, 263, 263, 755changes in, 316–317, 323, 326of climates, 727–728, 729 of clouds, 662–665, 663 dichotomous key, 312, 313 field guides, 314Linnaeus’s system, 307–308of living things, 296, 299–305, 309–310, 755of organisms by cell type, 208–210physical and genetic evidence for, 304–305of protists, 278, 755seven levels of, 309–310, 310, 311, 312, 326, 326 of simple machines, 151–155six kingdoms, 317, 317, 318, 319–323, 326, 755of tornadoes, 767, 767

classification systems, 531, 767, 767 Clean Air Act, 586, 631Clean Water Act, 586clear-cutting, 581, 581, 589climate, 516, 716, 716–717, 719, 742

altitude and, 721, 721 architecture and, 726changes in, 734–740classification of, 727–728, 729 of deserts, 518effect of ocean currents on, 723, 723 geography’s effect on, 719–723, 720, 721, 722, 723 of grasslands, 519greenhouse gases and, 626latitude and, 720, 720 seasonal changes as part of, 724–725, 724, 725 in temperate forests, 519–520of taiga, 518of tropical forests, 520of tundra, 517

climate zones, 727, 727–728, 728, 729, 742, 742, 745 cloud cover, 628, 628 clouds, 658

absorption of solar radiation, 628characteristics of, 662–665, 662, 663, 664, 665 cirrus, 662, 662, 663 cumulonimbus, 663, 664, 664, 673, 684, 691, 695cumulus, 662, 663, 664, 664, 695formation of, 661, 661, 674, 684lightning and, 605precipitation and, 668radiation and, 624satellite images of, 704 types of, FL17

club mosses, 386, 757 cnidarians, 414, 418, 418–420, 419, 420, 421, 421, 440,

440, 758

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R80 McDougal Littell Science Grade 6

coal. See fossil fuels.coastal ocean biomes, 293, 295, 498, 522–523, 523 coin game, 12–13, 16–17, 18, 21cold fronts, 684, 685, 688, 688, 695collisions, of atoms and molecules, 59, 621colonial organisms, 279Colorado River case study, 571, 571 color fixers, 228, 228 combustibility, 86combustion, 504, 505commensalism, 545, 545, 546, 556, 556 communication of results, 23, 28, 29, 30, 32communities, 534, 535

factors affecting, 549interrelationships of, 540–547succession in, 552–554, 552, 553

comparisons, making, 215competition, 540, 541, 541–542, 541, 542, 556

effect on populations, 551complicated machines, 170, 170–175, 178, 178 compounds, 62, 63, 64, 224–226Comprehensive Everglades Restoration Plan.

See CERP.compression, 116computers

cell studies with, 200modeling atmosphere and weather patterns, 715, 715

modeling DNA and, 214, 214 modeling effects of greenhouse gases, 633modeling strong force, 139nanotechnology to protect, 173predictions by, 633, 703, 705study of DNA with, 304

concentration, 239, 239 conclusions

drawing, R35evaluating, 431

condensation, 95, 95, 658, 658, 659cloud formation and, 661, 661 in water cycle, 503, 503

conduction, 620, 620, 638 conferences, 5coniferous trees, 344, 390, 391, 392, 518, 757

ecosystems supporting, 518, 518, 519, 520primary succession and, 552

Connecting Sciencesphysical science and earth science, 103, 617physical science and life science, 169, 462, 515

conservation, 585, 585, 587, 594of ecosystems, 584–586government efforts, 586–587, 588of resources, 560–563, 588–591

conservation of energy. See law of conservation ofenergy.

consistency, 20constants, 32, R30construction, 295consumers, 348, 510, 524

animals, 348–354, 349, 364

carrying capacity and, 551energy cycle and, 510, 510, 513, 514, 514 food chain and, 512place in food web, 367 predators and prey, 541, 550succession and, 554

continental air mass, 682continental climate, 722, 722, 722 continental drift hypothesis, 9–11, 10, 11, 736, 736 contraction theory, 10, 11control group, R30controlled variables, 17, 32convection, 620, 621, 621, 638, 721

thunderstorms and, 695conversions

metric to U.S. units, R21temperature, R21

conversions, energy, 118–123, 121, 123, 124–125efficiency, 123, 126–129, 131, 156–158, 156, 159loss to heat, 122, 123, 126, 127, 138, 157, 158, 171perpetual-motion machine and, 138

cooperation, 540, 543, 543 coral, 418, 443, 601–603coral reefs, 294, 295Coriolis effect, 651, 651, 653

high-pressure systems and, 686storm systems and, 689wind belts and, 651–652

cork cells, 194, 194 cowbirds, 547, 547 crabs, 437creative thinking, 6, 7creosote bushes, 536, 541crest, of wave, 749, 749Crick, Francis, 214, 214 critical analysis, R8, R8–9crocodiles, 454crustaceans, 434, 437cumulonimbus clouds, 663, 664, 664, 673

as eye wall of hurricanes, 691formation of, 684thunderstorms and, 695

cumulus clouds, 662, 663, 664, 664, 695curiosity, FL26, 6currents, 719, 723, 723, 736cuticle, 378, 379 cycads, 393, 757 cycles, 502, 614, 638. See also life cycle.

carbon cycle, 504–505, 504, 614, 615, 617, 617 carbon dioxide-oxygen cycle, 231, 232, 233,234–235, 234

effect on atmosphere, 615 energy cycle, 492, 508–512, 513, 514, 514, 533of energy transfer in atmosphere, 620–621, 620 nitrogen cycle, 505–506, 507, 614, 615 ozone-oxygen cycle, 625, 632, 634water cycle, 503, 503, 507, 614, 615, 659, 659

cyclones, 689–691, 690 cypress trees, 295 cytoplasm, 202, 202, 203, 205, 263

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Index R81

Ddams, 496, 562, 562, 571, 589

of beavers, 294data

collection of, 6, 7 describing a set of, R38–39description of, R36–37making tables of, R23reproducible, 9subjective, 9

data tables, making, R23da Vinci, Leonardo, 138DDT in food chain, 515, 515 decay. See decomposers.deciduous trees, 344, 347, 397, 519, 519–520

secondary succession and, 553, 553 decimals, R39–40

adding, R39dividing, R40multiplying, R40subtracting, R40

decomposers, 265, 265, 266, 359, 511animals, 349as biotic factors, 498–499, 498 carbon cycle and, 505energy cycle and, 511, 511, 512, 513 in food chain, 513 fungi, 322, 356, 360nitrogen cycle and, 507, 507 protists, 281round worms as, 423succession and, 553, 554

deep ocean biomes, 498, 522–523, 523 Deep Space 1, 38–39, 39–41deforestation, 581, 581 density, 25, 83, 89, 612, 638

air convection and, 621air pressure and, 646, 646 altitude and, 621, 622, 623equation for, 754identification of substances by, 99, 99 mass and volume and, 83measurement of, 25, 26–27separation of mixtures by, 103of water, 68

dependent variables, 16, 16, 32, R30operational definition, R30

deposition, of soil, 750desert biomes, 498, 499, 517, 518, 519, 587 desert subclimate, 728 design of experiments, 41, 602, 603, R28–35development, of organisms, 752dew, 659dew point, 660diagrams, 30, 32, 32, 677, 677 diatoms, 278, 278, 279, 759 dichotomous key, FL13, 312, 312, 313 diffusion, 238, 238–242, 239, 246–247, 248digestion, 349–350

of cnidarians, 419of fungi, 357, 360in sponges, 415in worms, 422

digestive system, 335, 350of arthropods, 433of jawless fish, 450of round worms, 423of segmented worms, 422

direction, 144 forces and, 147, 147 position and, 144

diseaseair pollution and, 631, 636bacteria and, 196, 265–267, 267, 270–271dust and, 601–603, 602 global warming and, 740molds and, 359parasites and, 758 protists and, 277, 280from viruses, 271, 272, 272, 274, 274, 275

displacement, 53, 53, 54–55, 107distance, 144

force, work and, 149, 149 position and, 144time, speed and, 145, 145

diversity. See also biodiversity.adaptations and, 336, 429of arthropods, 432of fish, 448of insects, 435of invertebrates, 413–414, 416scientific discoveries in, 368–371sexual reproduction and, 338

DNA, 214, 214, 225–226, 258, 263, 306in bacteria, 282 binary fission and, 258 coded information passed from parents, 258, 304models of, 214, 214 reproduction and, 338used to classify living things, 303, 368in viruses, 73, 271–272, 272

doldrums, 652, 653, 654dolphins, 186domains, 317, 317, 326, 755–758 Doppler radar, 670, 702, 714dormancy, 347Douglas, Marjory Stoneman, 490, 490 drizzle, 670, 671 droughts, 616, 739dry climate zone, 727, 728, 729 dry fruit, 401, 402–403, 402 dust, 630dust storms, 187, 600–603, 601, 602, 613, 616, 616 dyes, 228, 228

EEarle, Sylvia, 370Earth, 601–603. See also atmosphere; biomes; ecosys-

tems; environment.

IND

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R82 McDougal Littell Science Grade 6

atmosphere of, 611–613change over time, FL31, 552–554, 552, 553 consequences of human actions on, 578–579, 629–635, 739–740

continental drift, 9–11, 10, 11 curvature of, 651, 651–652, 651, 686, 689effect of hurricanes on, 186, 186, 691, 691 effect of natural processes, 601–603, 601, 602, 603,614, 615, 616, 616, 632, 634, 736–738, 745

effect of volcanic eruptions on, 552, 578, 616, 616,630, 630, 734–735, 734, 735

gravity of, FL31, FL33, 51, 114, 146mass and weight on, 51radiation on surface of, 625, 625, 628rotation and wind patterns, 651–652, 651, 653,686, 689

seasonal changes, 635, 656, 656, 724–725, 725 solar radiation on surface of, 618–621, 619 surface of, 750wind patterns and, 650–652, 650, 651, 653

earthquakes, FL31, 11, 21 earth science, FL27, FL30–31

and physical science, 103, 617Earth system, FL31easterlies, 652, 653 East Greenland currents, 723 echinoderms, 414, 429, 429–430, 429, 430, 431, 431,

440, 440, 758 eclipse, 139ecology, 495economy, 186ecosystems, 371, 492–493, 495, 495–496, 524, 581, 586.

See also environment.abiotic factors, 497–499in biomes, 516biotic factors in, 496carbon cycle, 504 carrying capacity of, 551, 568changes in, 489, 580–582, 581, 582 communities of, 534conservation of, 584–586, 585, 586, 587, 588–591, 588, 589, 590, 592–593, 594

cycles of matter in, 503–507, 503, 507, 512, 513 of deserts, 518energy cycle in, 508–512, 513, 514, 514 equilibrium in, 551fire control and, 485–486of Florida, 292, 294–295, 294, 295 of freshwater biomes, 521–522function of, 487of grasslands, 519, 519 habitats of, 532–533, 533 human impact on, 469, 485–487, 568–573, 574, 575–582, 578, 579, 580, 581

interaction of organisms in, 528, 528–529, 533,540–545, 546, 547, 548, 556

interrationships of, 293as level of organization of environment, 534, 535 limiting factors in, 549–551management of, 485–487

of marine biomes, 522–523niches in, 533organisms’ dependence upon, 495–499, 531patterns in, 534, 536–537, 536, 537 pollution of, 577–580, 578, 579, 580 populations in, 532, 532, 534recovery of, 293, 484–491, 484–485, 486, 553, 553,587, 587, 592–593

recovery programs, 584–586, 587, 588–591succession in, 552–554, 552, 553, 556, 556 swamps, 294, 295 of temperate forests, 519–520of taiga, 518, 518 trophic relationships in, 348–349, 366, 367, 403, 509–514, 510, 511, 533, 540, 541, 550

in tropical forests, 520of tundra biome, 517, 518

ecosystem services, 487, 563ectotherms, 460, 460–461, 464efficiency, 156, 156

calculating, 127, 156, 156, 159, 754of cars, 127, 127 of cooling devises, 127 and energy, 157of energy conversions, 123, 131of engines, 127, 157friction and, 157, 166ideal mechanical advantage and, 166of lights, 126–127, 127 of machines, 159technology to improve, 126–129of work, 156–158, 156

eggs, 452. See also sexual reproduction.of amphibians, 457of birds, 464, 468–469of fish, 451–452of reptiles, 458, 459, 459

egret, 295 Einstein, Albert, 139electrical charge, 605electrical conductivity, 100electrical energy

cars powered by, 117conversion to and from other types, 120, 121,123, 126

generation of, 128–130used by machines, 152

electric cars, 117electric energy, 41

in lightning, 605electrolysis, 44electromagnetic energy, 113, 120electron cloud, 748, 748electrons, 45, 748elements, FL33, 45, 62, 62

essential for life, 223–224, 224 periodic table, 768–769

El Niño, 738, 738, 738, R7, R7Internet activity, 717

embryo, 388

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Index R83

endangered species, 355, 555, 561, 561, 562, 563, 586 Endangered Species Act of 1973, 561, 586endocytosis, 243, 243 endoplasmic reticulum, 204, 205–206, 760, 761 endoskeleton, 447, 466, 467, 478, 481, 481 endotherms, 464, 464–465, 473energy, FL9, FL31, 112, 132, 761. See also kinetic

energy; potential energy.alternative forms, 40–41, 126–130, 589, 589 animal storage of, 474carbon cycle and, 504, 504 cellular respiration and, 232, 233, 763, 763 change of state of matter and, 84, 91–95changes in form, FL33, 118–120from charged ions, 39chemical, 229chemical bonds and, 224, 508chemosynthesis and, 509conduction, 100conversion of, FL29, 41, 118–123, 118, 120, 121,122, 123, 124–125

cycles of, FL31, 492, 508–512, 513, 514, 514,524, 533

digestion and, 350efficiency and, 131, 157electrical, 112, 605electromagnetic, 113, 113, 120fermentation and, 234–235flow of in food web, 367 forms of, 113from fossil fuels, 41geothermal, 589hydropower plants, 589infrared radiation, 625, 625, 626Internet activity, 109kinetic, 114, 114, 118, 119–120, 119, 120, 121, 122, 122, 132, 150, 690

laser, 40law of conservation of, FL33, 120, 122loss to heat, 150, 150 microwaves, 40, 113as need of living things, FL29, 192, 205, 220, 229–230, 231, 232, 233, 259, 508

nonrenewable, 41, 120nuclear, 40, 113photosynthesis and, FL29, 224, 230, 231, 341–342, 378, 382–383, 762, 762

plants storage of, 343potential, 114, 115–116, 115, 118, 119–120, 119,121, 122, 132, 132, 149, 154–155, 155, 690

radiation, 624–626renewable, 41, 120solar radiation, 618–619sources of, FL31, 278, 348–349, 576–577for space travel, 39–40storage of, 762–763stretching and, 116from the Sun, 40, 41, 113, 118, 120, 128–129, 192, 205, 229–230, 341–342, 378, 382–383, 508, 589,589, 618–621, 622, 623, 638, 649, 762, 762

thermal, 508

transfer of, 149, 149, 154–155, 155, 618–619, 619,620–621, 620

types of, 114ultraviolet radiation, 625, 625 usage in United States, 135used by machines, 151–157uses of, 111–112, 112 visible light, 40, 618–619, 619, 624, 625, 626, 704, 704

from wind, 112, 130, 130, 589work and, 154–155, 155

energy audit, 590energy efficiency, 123energy pyramid, 514, 551engines, 41

efficiency of, 127, 157for spacecraft, 39 steam-powered, 137, 138, 138

environment, FL28, FL29, 495, 578. See also atmo-sphere; biomes; ecosystems.

abiotic factors, 497–499adaptations to, 288–291, 288, 289, 336, 337, 343, 359, 380

animals’ responses to, 352–354, 352, 354, 420, 423of archaea and bacteria, 208–209, 209, 264, 264,322, 370

of arthropods, 432biodiversity hotspots, 371biotic factors, 496of birds, 463changes affecting diversity of organisms, 552–553, 577–582, 581, 582

changes affecting populations, 541, 550–552conservation of, 584–586, 587, 588–591, 594of crustaceans, 437cycles of matter in, 503, 503, 504–506, 504, 507 effect of human activities, 489, 575–582, 594, 601, 629–635, 630, 631, 632, 739–740

effect of human populations, 567–573, 568, 569,571, 572, 573, 594

effects of natural events on, 601–603energy cycle in, 508–512, 513, 514, 514 of fish, 448food chain, 512, 513 food web, 512, 513 of insects, 435Internet activity, 563, 565levels of organization of, FL15, 534, 535 living things’ dependence upon, FL28, FL29, 495, 531

living things’ response to, 192, 258of mammals, 475of mollusks, 426patterns in, 534, 535, 536–537, 536, 537 plants’ responses to, 345–347, 345, 346, 347, 364pollution and biodiversity, 577–580, 578, 579, 580 water cycle, 507

environmental concerns. See also pollution.Everglades restoration, 488–491red tides, 184–187

IND

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R84 McDougal Littell Science Grade 6

Environmental Protection Agency (EPA), 586, 631enzymes, 225equations, 28, 32, 754, R42. See also formulas.equator

climates near, 728 development of storms near, 689effects of global warming near, 740solar radiation near, 619, 712temperatures near, 720, 720 wind patterns and, 652, 653

erosion, 573, 579, 588, 616, 750Erwin, Terry, 370estimates, 21estuaries, 294, 489, 491, 522, 522 euglena, 199, 219, 278, 278 Eukarya, 210, 317, 317 eukaryotes, 210, 210, 320, 321, 376. See also animals;

plants; protists.plants and animals as, 760protists, 276–281

eukaryotic cells, 202, 202, 203–206, 203, 204, 205, 209,216, 216, 317, 317, 760, 761 fermentation in, 234organelles of, 210

evaluation of results, R8checking consistency, 21checking units, 20–21media claims, R8using estimates, 21

evaporation, 93, 93, 658, 658, 659, 660cooling in urban areas by, 730global warming and, 739from leaves, 378, 380separation of mixtures by, 102, 102 tropical storm formation and, 689in water cycle, 659water cycle and, 503, 503, 614, 615

Everest, Mount, 612 Everglades, 488–491, 488, 489, 491 Everglades: River of Grass, The (Douglas), 490evidence, 9–11, 25, R8evolution, 303, 323, 454

classification and, 304, 316of land animals, 454–455, 475of plants on land, 382–383

excretory system, 422exercise, 236exocytosis, 243, 243 exoskeleton, 433, 433 experiences, 9experimental bias, 27, 27–28experimental group, R30experiments, 6, 7–8, 7

analyzing, 35, 107, 107 conclusions, drawing, R35controlled, R28, R30dependent variable, measuring, R31designing, 41, 602, 603, R28–R35determining purpose, R28equipment, R12–R19evaluating results, 18–21, 19, 20, 21, 26–27, 26, 27

hypothesis, writing, R29identifying bias, 27materials, determining, R29measurements and, 15–16observations, recording, R33patterns in, 23precision and accuracy, R22presentation of results, 28, 29, 30, 30, R23–R27procedure, writing, R32purpose of, 31questions for further research, R35records of, 24–25results, summarizing, R34safety, R10–R11senses and, 14–15variable and constants, determining, R30variables and, 16–18, 16, 18

exploration, 2–3, 9Explore

activity and life, 191air masses, 681air pollution, 629air pressure, 645arthropods, 432changing forces, 160classification, 307communication, 23condensation, 658counting animals, 531diffusion, 238energy, 111energy changing form, 508environmental impact, 584falling objects and air quality, 611feathers, 463fish’s shape, 446 food molecules, 223leaves, 375machines, 151magnification, 189mixed substances, 61moss plants, 382motion, 143moving on land, 454mushrooms, 356organisms, 255photosynthesis, 221physical properties, 81plants and soil, 493population growth, 549sharing resources, 567similar objects, 49solar cells, 126solar energy, 649, 719solids and liquids, 67specialization of cells, 208stored energy, 341viruses, 270warmth, 14, 14 water cycle, 502weather maps, 700

IND

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Index R85

worm movement, 418your environment, 495

extended-response questions (ER), FL35, FL47–48, FL47extinction, FL29, 582

of Dodo bird, 396laws to prevent, 561natural causes of, 735studies to prevent, 371

Extreme Scienceamazing seeds, 396cumulonimbus clouds, 673looking at atoms, 59 new insect species, 315tulipomania, 275

eye of hurricane, 690, 690

Ffact, R9

difference between opinion and, R9factors, 12

constants, 16controlled variables, 17dependent variables, 16independent variables, 16uncontrolled factors, 18

Fahrenheit scales, 15, 15 fall. See seasons.family, 310, 311, 312farming

biodiversity and, 294effects of global warming on, 740pollution and, 409, 562, 579, 588, 630, 632 secondary succession and, 553sustainable practices in, 588urbanization and, 573use of fertilizers in, 550

fat, body, 474fats. See lipids.fatty acids, 225, 225 faulty reasoning, R7, R7 FCAT Practice, FL35, 35. See also Sunshine State

Standards.analyzing data, 251, 285, 409, 409, 443, 597analyzing diagrams, 481, 481, 677, 677 analyzing experiments, 107, 107 analyzing graphics, 181, 181, 329analyzing maps, 711, 711 euglena puzzle, 219interpreting data, 745, 745 interpreting diagrams, 367interpreting graphs, 77, 77, 135, 135, 527, 641, 641 understanding symbiosis, 559

FCAT questionsextended-response questions (ER), FL35, FL47–48, FL47

gridded-response questions (GR), FL35, FL35, FL45, FL45

multiple-choice questions (MC), FL35, FL44short-response questions (SR), FL35, FL46, FL46

feathers, 463, 465, 466, 467 feeding, 423, 451

of arachnids, 438, 438 of arthropods, 438, 439of birds, 466, 470–471, 470, 471 of cnidarians, 418–419, 419 of crustaceans, 437of echinoderms, 429of fish, 448, 450, 451, 452 of insects, 435of mammals, 474, 543of millipedes and centipedes, 439of mollusks, 427, 427, 428, 428, 430, 430, 431, 431 predator-prey relationships, 353, 353, 541, 543, 550, 551, 556

of sponges, 415, 415 of worms, 422, 422

feeding relationships. See also consumers; cycles;decomposers; producers.energy pyramid, 514, 551food chain, 512, 515, 515, 540, 541food web, 366, 367, 437, 512, 513 predator-prey relationships, 353, 353, 541, 543, 550, 551, 556

Felidae (cat family), 301, 301, 310 fermentation, 234, 234–235, 236, 248ferns, 383, 383, 385–387, 386, 387, 406, 498, 757 fertilization, 338, 338, 385, 391, 391

of amphibian eggs, 457of bird eggs, 468of cherry trees, 398, 399 of cnidarian’s eggs, 420 of fern eggs, 387of fish eggs, 451–452in mammals, 476of moss eggs, 385of pine trees, 390, 391 of reptile eggs, 459in seed plants, 388, 390, 397–398, 399

fertilizers, 185, 550, 588, 630 fibers, 228, 228 field guides, 312, 314, 314, 324–325field work, 6, 7 filament, 400, 400 filtration, 101, 102, 270, 570fire, 553

as abiotic factor, 519effect on the atmosphere, 616, 630, 632management of ecosystems with, 484–485,485–487, 486

secondary succession following, 553, 553 fish, 448–452, 449, 450, 454–455, 478, 478

commensalism of, 545, 545 effects of global warming on, 740red tide and, 186

Fish and Wildlife Conservation Commission, 186fishing, 293fishing industry, 186fixed pulley, 162, 162 flagella, 215, 263, 279, 280, 415, 415

IND

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R86 McDougal Littell Science Grade 6

flash floods, 696flatworms, 423, 423, 758 flight, 465–466, 467, 468, 468 floods, FL17, 726, 739

animal shelters during, 294control of, 293damage in California, R7

Florida Black Bear, 294, 294 Florida Comprehensive Assessment Test. See FCAT

Practice; Sunshine State Standards.Florida Connections

Everglades Restoration, 488–491, 488, 489, 491 Florida’s Biodiversity, 292–295, 292, 293, 294, 295 Hydrogen: From Rockets to Cars, 42–45, 42, 43,44, 45

Let’s Bolt! Lightning in Florida, 604–607, 604, 605,606, 607

Red Tide, 184–187, 184, 185, 186, 187 Florida International University, 45Florida key deer, 293, 294Florida panther, 293, 294 489, 489Florida’s ecosystems, 294, 488, 489–491, 489, 491 flower, 398, 399, 400, 400, 406, 406, 544, 544flowering plants, 485, 485, 758

flowers of, 400, 400 fruit of, 401human use of, 403–404, 403, 404 reproduction of, 397–398, 399, 401–403, 544, 544

fog, 630, 665, 665 food. See feeding.food chain, 512, 540, 541

biomagnifications in, 515, 515 contamination of, 489

food web, 366, 367, 437, 512, 512, 513 habitat changes and, 580pollution and, 579red tide and, 186

foot of mollusks, 426, 426, 427, 429, 429, 430force, FL31, FL33, 143, 143–150, 160

acting on objects, 137, 137, 138balanced, 148, 148 discoveries about, 136distance, work and, 149, 149 energy transfer and, 149equation for, 754friction, 147, 148, 150gravity, FL31, FL33, 146machines, work and, 140, 151–157motion and, 146–147, 147 multiple, 148, 148 in nucleus of atom, 139unbalanced, 148, 148

forecaster, of weather, 705, 708forest fire. See fire.forests

conservation of, 560fire and, 485–486, 486 in Florida, 294, 294 organisms of, 498pollution and, 580

as renewable resource, 576, 576 sustainable practices in, 589urbanization and, 573

forms of energy, 113conversions of, 118–125, 121, 123, 132energy as a constant, 122, 132

formulas, 127, 131, R42acceleration, 754area, R43, R43average speed, 145, 754current, R42density, 83, 89, 754energy efficiency, 131force, 754frequency, 754for gravitational potential energy, 154mechanical advantage, 153, 166, 167, 168momentum, 754percent efficiency, 156, 754use of, 131volume, 52, R43, R43wavelength, 754work, 149, 754

fossil fuels, 630advantages and disadvantages of, 120, 128alternatives to, 41, 117, 127–130, 589, 589, 634carbon cycle and, 504, 505hydrogen fuel and, 43, 43 as nonrenewable resources, 41, 120, 576–577, 576 pesticides and fertilizers made from, 588pollution from, 578, 630, 630, 632 source of, 403

fossils, 9, 10, 10, 468, 750evidence from, 323, 382, 392, 432, 475evidence in, FL29taxonomists use of, 302, 304

Fourier, Jean-Baptiste, 713foxes, 517, 518, 562, 562

adaptations of, 336, 337 fractions, 555, R41frame of reference, 144, 144 Franklin, Benjamin, 605, 713Franklin, Rosalind, 214freeze-avoidance, 290freeze-tolerance, 290–291freezing, 92, 92 freezing point, 92, 96–97, 748freezing rain, 670, 671 frequency, 749, 754freshwater biomes, 292, 293, 521–522, 522

pollution and, 579–580, 579, 580 recovery of, 488–491, 488–489, 490

friction, FL33, 147, 148complicated machines and, 171efficiency and, 166heat and, 118, 122, 138, 150, 157in outer space, 40, 165reducing, 158

Friends of the Everglades, 490frogs, 290, 454, 454, 456, 457. See also amphibians.

IND

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Index R87

Frontiers in ScienceChilling Changes, 288–291, 288–289, 290 Dust in the Air, 600–601, 601–603, 602 Ecosystems on Fire, 484–487, 484–485, 486 Fuels of the Future, 38–41, 38–39, 40

fronts, 684, 685, 688, 688 cold, 684, 685, 687, 688, 688, 692, 695low-pressure systems and, 687measurement of speed of, 686, 686 movement of, 687, 687, 688, 688 naming of, 714stationary, 684, 685storms and, 695 symbol for on weather maps, 702–703, 702 thunderstorms and, 695warm, 684, 685, 687

frost, 659fruit, 398, 401, 402, 406, 406 fuel cells, 589Fujita scale, 767, 767 fulcrum, 161, 161 fulgurites, 606, 606 function, 334–335

basic processes in cells, 195, 195, 203, 204, 205–206, 224–226, 229–230, 231, 234

diffusion and, 238of specialized cells, 210–211, 211 structural basis of organisms, 192, 211–213, 212

fungi, 257, 322, 356, 357, 361 characteristics of, 322, 357as decomposers, 356, 364, 511, 511 harmful and helpful effects of, 360–361, 361,602–603, 602

honey mushrooms, 257–258reproduction of, 357–358, 385specialization of cells, 333structure of, 357, 357 types of, 358–359, 358, 359

Fungi, 319characteristics of, 317, 317, 318, 321, 322, 357, 756

GGalápagos Island, 532–533, 532, 533 galaxy, 750gales, 765 Galilei, Galileo, 138garbage, 569, 569, 579Garrison, Ginger, 602, 602 gases, 68, 68, 90

absorption of radiation, 624–627, 625, 627 in the atmosphere, 613, 632–635, 632, 638behavior of, 69, 69, 73, 73, 77 changes of state, 93, 93, 94, 94, 95, 658composition of, 72, 72 density of, 623as pollution in air, 630temperature and, 621

gastropods, 426, 427, 427, 429Gay-Lussac, Joseph Louis, 713gears, 171, 171

geckos, 462, 462 genes

adaptations and, 336in bacteria, 262, 263 master control gene, 291nucleus and, 262traits passed to offspring by, 258, 304in viruses, 271, 272

genetic engineering, 752genetic evidence, 303, 304, 305 genetic material

binary fission and, 258, 258, 262meiosis and, 388, 391

genus, 308, 309, 310, 311, 312geography, 737

continental drift and, 736effect on climate, 719–723, 720, 721, 722, 723, 730, 731, 731

ice ages and, 737geosphere, FL31geothermal power, 589germination, 389, 396germs, 196. See also bacteria; viruses.gestation, 476, 476 gills, 351, 351, 427

of amphibians, 457of fish, 449, 449 of mollusks, 427, 428

ginkgoes, 393, 393, 757 gizzard, 466glaciers, 552, 570, 739 Glen Canyon Dam, 562, 562 global cooling, 737global information systems (GIS), 562global warming, 43, 633–634, 633, 638, 739–740, 739 global wind belts, 651, 652, 653, 654global winds, 650, 651, 652, 653, 654, 712

movement of air masses and, 683, 687glucose, 229, 229–230, 231

cellular respiration and, 232, 233, 763, 763 cellular transportation of, 240, 240 fermentation and, 234photosynthesis of, 229–230, 231, 762, 762 storage of, 230, 232

glycerol, 225glycogen, 232gnetophytes, 393Goddard, Robert H., 139Golgi apparatus, 204, 206, 760, 761 Grand Canyon, 562, 562 Grant, Ulysses S., 560graphs, 32

bar, 29, 135, 135, 527, R26, R26 circle, 28, 29, 66, R25, R25 double bar, R27, R27, R34, R34 interpreting, 77, 77, 135, 135, 237, 527, 527 line, 29, 77, 77, 261, 261, 527, 641, 641, R24, R24,R34, R34

presentation of scientific data, 28, 29 scatter plot, 29

grasses, 343, 397, 553, 553

IND

EX

R88 McDougal Littell Science Grade 6

grassland biome, 486–487, 486, 496, 517, 519, 536, 536 gravitational potential energy, 154–155gravity, FL31, FL33, 146

discovery of, 138effect on light, 139, 139 orbit of Moon and, 138plant responses to, 345potential energy and, 115, 119weight and, 51, 51 work and, 154–155, 155

Great Lakes, snow effects from, 692Great Pyramid, 175greenhouse effect, 626, 626–627, 627

ice ages and, 737naming of, 713

greenhouse gases, 626function of, 626–627, 627 global warming and, 633–634, 739–740human activities producing, 632–633, 632 monitoring of, 714natural sources of, 632–633, 633

Greenland, 720, 739gridded-response questions (GR), FL35, FL35,

FL45, FL45grids, 405ground-based weather stations, 701, 701, 704, 714ground water, 499, 569, 580group, on periodic table, 768 growing season, global warming and, 740growth, FL29, 192, 257

of humans, 752of mammals, 477of plants, 376, 380–381

Gulf of Mexicoocean currents in, 723, 723 tornado formation in, 697

Gulf Stream, 723, 723 gymnosperm, 390, 391, 392, 392–393, 393, 406, 406

Hhabitats, 532, 532–533, 533, 543, 556

effects of loss or change in, 549, 580–582, 581, 582 in Florida, 293, 294 human destruction of, 489, 573interrelationships within, 540–545, 542, 543, 544,545, 546, 547, 547, 548

of manatees, 293protection of, 585

hail, 670, 671, 672, 696hair, 473, 473 Half Moon Bay, California, 724, 724 Halley, Edmund, 712 halophiles, 264, 264 hardwood hammocks, 294harmful algae blooms (HAB), 184–187Harrison, John, 368heat. See also temperature.

as absorbed sunlight, 618conduction properties, 100, 100

as energy, 118, 120, 122, 126friction and, 123, 126, 127, 157sources of, FL31wind formation and, 649–650, 654, 655, 655, 656

herbivore, 349, 367, 435Hero of Alexandia, 137heterotrophs, 348, 356–357, 357. See also animals.hibernation, 289, 354, 474highland climate zone, 727, 728, 729 high-pressure system, 686, 686, 687, 702, 703Hooke, Robert, 194hormones, 346hornworts, 383, 757 horse latitudes, 652, 653, 654horsetails, 376, 376, 386host cell, 272, 273, 274hot air balloons, 713, 713 humans

biodiversity and, 293classification of, 312conservation efforts, 585–586, 587, 588–591dependence on plants, 403effect of pollution on, 631effect on climate, 730, 739effects on atmosphere, 601, 629–635, 630, 632,633, 635, 638

effects on environment, 295, 469, 485–487, 489, 564, 568–573, 575–582, 592–593, 601

elements of body of, 224 global warming and, 633, 740lightning strikes and, 607organ systems of, 213population increases, 567–568, 568, 594, 597as predators, 295red tide and, 186research involving, 753uses for plants, 403–404, 403, 404

humid continental subclimate, 728, 729 humidity, 660, 681–682

thunderstorms and, 695humid subtropical subclimate, 728, 729 humid tropical climate zone, 727, 728, 728, 729 hurricanes, 689, 689–691, 690, 691, 708, 708, 714, 765

red tide and, 186, 186 warning systems for, 714, 714

hydra, 199, 418hydrogen

fossil fuels and, 43, 43as fuel, 42–45from water, 44, 45in human body, 224, 224, 225storage of, 42

Hydrogen for Florida, 45hydropower, 589hydrosphere, FL31hyphae, 357, 357, 358, 360, 360, 361hypothesis, 8, 31, R3, R29

becoming a theory, 9–10evaluating, 699testing, 8–9

IND

EX

Index R89

theory compared with, R3writing, 31, R29

Iice

in clouds, 669, 695clouds formation and, 661rain formation and, 659, 670

ice ages, 736–737, 737, 737 icecap subclimate, 728, 729 ice sheets, retreat of, 739, 739 ice storms, 693, 693 ideal mechanical advantage, 163, 166–168images, 30, 30, 32, 32 incineration, 570inclined plane, 160, 164, 164, 166, 166, 178incubation, 469independent variables, 16, 32, R30

controlled, 17graphs and, 29 operational definition, R31

Indian Ocean, storms in, 689Indian River Lagoon, 295, 491Indonesia, 738inference, 548, R4, R35information, evaluation of, R8informed consent, 753infrared radiation, 625, 625

absorption of, 620, 625, 625, 626, 627, 627, 739greenhouse gases and, 627ozone layer and, 626satellite images of, 704, 704, 714

insects, 434, 435, 435–437, 435 compound eye, 369 diversity of, 315, 435mutualism and, 546 and plant reproduction, 544, 559population patterns of, 541social behaviors of, 543, 543

instrumentsaccuracy of, 20experimental bias and, 27–28for observing, 15

insulationfeathers as, 465in mammals’ bodies, 474

insulators, 100, 100 integers, 507interaction, FL29international aspects of science

conservation and, 588global cooling, 737global warming, 633–634global winds, 650–651, 650, 651 greenhouse effect, 626–627, 627, 716, 737ozone layer, 634–635

International System (SI) units, 16, 22, R20–21Internet activities

atmosphere, 609

bee dance, 331carrying capacity, 529cells, 189distribution of reptiles and amphibians, 445El Niño, 717energy, 109environment, 563, 565invertebrate diversity, 411Linnaeus, Carolus, 297machines, 141microscopic life, 253mollusks, 426–429, 426, 427, 428, 429 photosynthesis, 221physical and chemical changes, 79physical states, 67prairie ecosystem, 493scales, 47scientists, 3sponges, 415–416, 415, 416 sprouting seeds, 373weather safety, 679wind, 643worms, 422–423, 422, 423

interpretation, 6, 7 interpreting diagrams, 367, 367 invasive species, 581–582, 582 invertebrates, 410, 410, 413, 440

arthropods, 432–433, 434, 435–439, 435, 437,438, 439

cnidarians, 418–420, 419, 420 diversity of, 413–414echinoderms, 429–430, 429, 431, 431

Investigate. See also Chapter Investigations.air masses, 683air pressure, 647binomial nomenclature, 308capturing sun’s energy, 384carbon, 505cell models, 213cell transport, 244chemical changes, 87classifying leaves, 302cleaning oil spills, 592 climate, 521climate changes, 735condensation, 661copper pennies, 25Coriolis effect, 651decomposers, 511efficiency, 157eggs, 460fermentation, 235flower parts, 401gas in air, 612greenhouse effect, 626heating and cooling rates, 721how body fat insulates, 474ice, 692insect metamorphosis, 436invertebrates, 414

IND

EX

R90 McDougal Littell Science Grade 6

limiting factors, 551liquids, 71mass of and atom, 57microorganisms, 259mixtures, 64mollusks and echinoderms, 428oil and water, 226owl pellets, 350particles in air, 577pine cones, 392potential energy, 115precipitation, 669protists, 277pulleys, 163resources, 570separating mixtures, 101solar energy, 129solar radiation, 619specialization, 334species interactions, 543speed, 146updrafts, 696using a microscope, 198 variables, 17viruses, 271what plants need to grow, 342

investigation, 6, 7. See also experiments; scientific inquiry.

ion engines, 39, 39 ions, 45, 749islands, global warming and, 740isobar, 703, 703

Jjawless fish, 450, 450 jellyfish, 418, 420, 420, 545, 545 jet streams, 654, 654, 657, 657, 714

movement of air masses and, 683joints, 433, 433 joules (j), 149, 156

KK. brevis, 185–187keratin, 459kinetic energy, 114, 132, 150

change to and from potential energy, 119–120, 119, 121, 122

conversion to other forms of energy, 118, 120, 120, 122

of hurricane, 690mass and speed and, 114, 114 of tropical storms, 690

kingdoms, 256, 257, 310, 310, 311, 312, 316Animalia, 256, 317, 317, 318, 319, 320, 320, 758 Archaea, 262, 264, 264, 755 Bacteria, 193, 207, 209, 262–263, 263, 265–267, 282, 282, 755

Fungi, 317, 317, 318, 319, 321, 322, 357, 756

Plantae, 317, 317, 318, 319, 320, 320, 333, 376, 757–758

Protista, 210, 276–281, 278, 282, 282, 755–756 table of, 755

Kyoto Protocol, 634, 635

Llab equipment, R12–20

beakers, R12, R12 double-pan balance, R19, R19 forceps, R13, R13 graduated cylinder, R16, R16 hot plate, R13, R13 microscope, R14–15, R14 rulers, metric, R17, R17spring scale, R16, R16 test-tube holder, R12, R12 test-tube rack, R13, R13 test tubes, R12, R12 triple-beam balance, R18, R18

laboratory experiments, 6, 7 Labrador currents, 723labs. See experiments.Lacey Act, 561lactic acid fermentation, 234–235, 236lake-effect snowstorms, 692Lake Erie, 579Lake Placid mint, 293lakes, 521–522, 522, 579–580, 579, 580

acid rain and, 672pollution of, 578, 579, 589snow and, 692

land biomes, 517–520, 517, 524land breezes, 655, 655 landfills, 569, 569, 579landscape

reshaping by animals and plants, 361, 496, 552–553, 552, 571, 572

reshaping by humans, 564–565, 571–573, 572,573, 576

La Niña, R7lanthanides, 769 larva, 416

of amphibians, 457of cnidarians, 420of insects, 436, 437, 437

laser light, 40Las Vegas, Nevada, 572, 572 lateral line, 449, 449 latitude, 720, 720

global warming and, 739global wind patterns and, 651, 652, 653, 654

lava flows, primary succession after, 552, 552 law of conservation of energy, FL33, 122, 132laws of motion, 137, 138leatherback sea turtle, 453, 453 leaves, 380, 381

of conifers, 392exploration of, 375

IND

EX

Index R91

of ferns, 387structure and function of, 377, 377, 378, 378, 379

LEDs. See light-emitting diodes (LEDs).Leeuwenhoek, Anton van, 194, 276, 369Leonardo da Vinci, 138lever, 137, 160, 161, 161, 178

ideal mechanical advantage, 168real-world examples of, 168, 169

lichens, 360, 360–361, 360, 517, 546, 552, 552 life cycle

of amphibians, 211, 456, 457of angiosperms, 397–398, 399 of cnidarians, 420, 420 of crustaceans, 437of ferns, 387of fish, 451–452of gymnosperms, 390, 391 of insects, 436–437, 437 of jellyfish, 420, 420 of mosses, 384–386of plants, 376 (See also archaea)of sponges, 416

life science, FL27, FL28–29, FL28physical science and, 169, 462, 515, 552

lightas abiotic factor, 496as biotic factor in ecosystems, 498as energy, 113, 118, 120, 126fungi response to, 359improvements in efficiency of, 126–127lasers and, 40matter and, 49photosynthesis and, 499plant responses to, 346, 346 reflection and absorption of, 618–619visible light, 40, 618–619, 619, 624, 625, 704, 704

light-emitting diodes (LEDs), 127, 127 light microscope, 759, 759 lightning, 673, 673

in blue skies, 606–607, 607 effects of, 696in Florida, 604, 605, 605, 606, 607 formation of, 694–695nitrogen cycle and, 505, 507 prairie fires started by, 486–487safety tips, 60730-30 rule, 607thunder and, 606

light-years, 751limiting factors, 550, 551, 569

on human population growth, 568line graphs, 261, 261, 741line symmetry, 417, 417 Linnaeus, Carolus, 307, 319, 321, 369

Internet activity, 297lipids, 224, 225, 225, 227, 248, 248 liquids, 68, 68, 90

behavior of, 69, 69, 71boiling of, 94, 94 condensation of, 95, 95

evaporation of, 93, 658melting and freezing of, 91–92, 91, 92

Little Grass Frog, 294liverworts, 383, 386, 757 living space, 192, 551

as need of living things, FL29patterns of, 536, 536. See also environment; habitats.

living things, FL14, 282, 299–305. See also adaptation; animals; archaea; bacteria; fungi; multicellularorganisms; organisms; plants; protists; unicellularorganisms.

basic unit of, 188, 193binomial nomenclature and, 308–309, 309 as biotic factors, 496cells and, 194–195characteristics of, FL29, 191–192, 257–258classification of, 309–310, 310, 311, 316–317, 317,318, 319–323, 326, 755–758

classification of by cell type, 208–210communities of, 534dependence on environment, FL28, 531diversity of, FL29, 255–256, 256 effect of global warming on, 740effects of freezing on, 288–291habitats of, 532–533, 533 identification of, 312, 313, 314, 314 interrelationships of, FL15, 528, 528–529, 540–547, 541, 542, 543, 546

levels of organization, 534, 534 loss or change in habitats and, 580–582needs of, FL29, 192, 193, 259niches of, 533nonliving things and, 191organization of, 211–212, 212, 334–335pollution and, 578–580populations of, 532, 532, 534, 550–551, 550 source of, 195specialization of cells, 333, 334spontaneous generation and, 196–197, 197 types of molecules in, 224–226

lizards, 454, 455, 518, 518 lobsters, 437local winds, 655, 655 logic. See critical thinking skills.London, England, 630, 723, 723 long-billed marsh wrens, 295low-pressure systems, 686–687, 686, 687, 687, 689–693,

702, 703, 708hurricanes and, 689–691, 690, 691 winter storms and, 692–693

lunar eclipse, 751, 751lungs, 351, 351, 427

air pollution and, 631, 636of amphibians, 457of birds, 467 of reptiles, 458

lysosomes, 204, 206, 760, 761

IND

EX

R92 McDougal Littell Science Grade 6

Mmachines, 140, 151, 151–155. See also cars; computers;

simple machines.change direction of force, 153, 161, 161 change size and distance of force, 152, 154, 161, 161, 164

Chapter Investigation on, 178compound machines, 170–175, 178, 178 efficiency of, 156–158energy transfers by, 151–157Internet activity, 141mechanical advantage, 153, 166–168microtechnology and nanotechnology, 172–173perpetual motion, 137, 137, 138, 139robots, 174, 175, 370, 371

magnetism, 100, 100, 101, 103making comparisons, 215malaria, 280mammals, 472, 473, 473, 475, 476, 477, 478, 478

body heat of, 473–474characteristics of, 473, 473 diversity of, 472–473environments of, 475reproduction and development of, 476–477, 477

mammary glands, 477, 477 manatees, 186, 292, 293, 294, 601–603mangrove forests, 295, 489mantle, 426, 428manufacturing

pollution from, 586, 630use of robots, 175

maps, analysis of, 711, 711 marine biomes, 498, 522–523, 523

biotic factors, 496carbon cycle in, 504, 504 commensalisms in, 545effect of global warming on, 740effect on climate, 721, 738

marine chronometer, 368, 368 marine climate, 722, 722, 722 marine west coast subclimate, 728, 729 maritime air mass, 682marshes, 293, 294, 295, 489marsupials, 477mass, 50, 74

of an atom, 57density and, 83, 89identification of substances and, 99kinetic energy and, 114matter and, 49, 50measurement of, 51, 54–55as physical property, 82volume and, 54–55weight compared to, 51

mass transit, 590, 590 materials

for experiments, R29needed by living things, 192, 226, 226, 259

Mather, Stephen, 561, 561

math skills, R42–43. See also units of measure.adding integers, 507adding measurements, 657algebraic equations, 628area, R43, R43 changing ratios to percents, 159circle graphs, 66, 66, 340comparing data, R38–39converting units, 22decimals, R39, R39–40describing a set of data, R36–37determining rates, 686, 688dividing by decimals, 453finding volumes, 583formulas, 52, 83, 89, 131, 153, 154, 156, 166, 167, 168, R42–43

fractions, R40 interpreting graphs, 237interpreting line graphs, 741line symmetry, 417, 417 making a line graph, 261, 261 mean, R36median, R36multiplying a fraction by a whole number, 555percents, R40proportions, R39 range, R37rates, R38 ratios, R38 scientific notation, 207, R44significant figures, R44solving proportions, 89using formulas, 131using grids to estimate, 405volume, R43, R43 writing percent, 306

mating, competition within species, 548matter, FL31, 49, 74, 78

changes in form, FL33changes of state and, 90–95chemical changes, 86–88chemical properties, 86, 104conservation of, FL33cycles of in ecosystems, FL31, 492, 502–506density of, 83, 89, 99, 99, 103elements of, 223forces acting on, FL31, 143gas, 68, 69 liquid, 68, 69 mass, 51physical properties, 46, 54, 81–85, 98–100, 103, 104pure and mixed, 61–65recycling of. See cycles.smallest units of, FL33, 56–57solid, 68, 69 states of, 67–73, 74volume of, 51

Mauna Loa Observatory, 714, 714, 741meadow ecosystem, 510mean, R36, R36

IND

EX

Index R93

measurements, 32, 657accuracy of, 20, 20 of air pressure, 648barometric pressure, 703, 703 of cells, 200comparing information and, 15, 15 consistency of, 21of density, 83of mass, 50numbers and units, 15as objective results, 9precision of, 18–19of volume, 52–53, 53, 54–55, 82of weight, 51of work, 156

mechanical advantage, 153, 163. See also efficiency.calculating, 166of gears, 171of inclined planes, 166–168

mechanical energy, 113, 113, 152median, R36, R36 medicines, 293–294Mediterranean subclimate, 728, 729 medusa, 420, 420 meiosis, 338, 338, 391

in moss plants, 385in seed plants, 390, 398, 399

melting, 91, 91–92, 91 melting point, 91, 91–92, 103, 748meniscus, R16, R16Merian, Maria, 368Mesosaurus, 10 mesosphere, 622, 623, 638metals, 769 metamorphosis, 436, 436meteorologists, 700, 700–701, 703, 708, 719, 766meters (m), 22methane, 630, 632 methanogens, 264, 264, 267metric system, 22, 54, R20–21

changing metric units, R20conversing to U. S. units, R21

Meyers, Norman Mike, 371microclimates, 730, 730, 732–733microorganisms, 256, 256–257, 256, 282, 321. See also

archaea; bacteria; protists; unicellular organisms.as biotic factors, 496characteristics of, 258–259discovery of, 369needs of, 259

microscopes, 194, 194, 216, 369, 369 classification of living things and, 299, 317invention of, 194light, 759, 759 make slides for, 200making a slide or wet mount, R15, R15,parts of, R14, R14scanning tunneling microscope (STM), 60, 60, 173types of, 200–201use of, 198–199, 198, 276viewing an object, R15

microscopic organisms, 253microtechnology, 172–173microwaves, 40, 113migration, 289, 354, 537

of birds, 463, 466, 468Migratory Bird Treaty of 1918, 561milk, 477Milky Way, 750millibars, 703, 703 millipedes, 439minerals, 103, 103, 497, 498, 551, 570mistletoe, 546 mites, 438mitochondria, 204, 205, 205, 232, 233, 761

cellular respiration and, 763, 763 function of, 760

mixtures, 63, 63, 65, 66, 66 compound and, 64heterogeneous and homogeneous, 65separation of, 101–102, 103, 103

mobile, 420mode, R37, R37 moist mid-latitude climate zone, 727, 728, 729 molds, 281, 358–359, 359 molecules, 58, 58, 68, 617, 617

air pressure and, 645, 646, 646 changes of state and, 90, 91, 92, 93, 94, 95chemical changes and, 86–88of compounds, 63conduction of energy by, 620–621diffusion of, 238–241energy stored in, 229in living organisms, 224–226, 248microtechnology and nanotechnology, 173motion of, 59, 59, 67, 69, 70, 71, 72, 73, 73, 238polar molecules, 226, 226 states of matter and, 67–73

mollusks, 414, 426, 440, 440 bivalves, 427, 427, 429cephalopods, 428, 429characteristics of, 758 gastropods, 426, 427, 427, 429

molting, 433, 433 momentum, 754monsoon, 656Montreal Protocol, 635Moon, FL33, 751moose population, 550, 550 mordants, 228mosses, 383–386, 385, 406, 498, 545, 552, 552, 757 motion, 144, 238. See also air movement.

changes of state and, 91, 92, 93, 93, 94, 94 of continents, 9–10, 10 forces and, 138, 143, 146–147, 147 in gases, 67, 68, 69 in liquids, 67, 68, 69, 71, 72, 73, 73 of molecules and atoms, 59, 59, 91position and, 144in solids, 67, 68, 69, 70

motor. See engines.mountain breezes, 655

IND

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R94 McDougal Littell Science Grade 6

mountainschange over time, FL31climate and, 727, 728, 729, 730formation of, 10, 11rain shadow caused by, 731, 731 temperature and, 721, 721 zones, 517

movable pulley, 163, 163 movement of matter, FL31Muir, John, 561multicellular organisms, 193, 193, 199, 216, 330, 364.

See also animals; plants.adaptations of, 336eukaryotic cells of, 202, 202 fungi, 356–358organization of, 334–335photosynthesis of, 341–343protists, 277, 278, 278, 279, 281, 281, 321reproduction of, 336, 338–339seeds as, 389specialization of cells, 210–211, 211, 333, 334

multiple-choice questions (MC), FL35, FL44Murcutt, Glenn, 726muscular system, 335, 352

of arthropods, 433of cnidarians, 419of fish, 448–449of round worms, 423of segmented worms, 423

mushrooms, 256, 357, 358 mussels, 426mutualism, 544, 544–545, 544, 546, 556, 556 mycelium, 357, 358

Nnaming organisms, 369nanotechnology, 172–173, 173, 173 Natashquan, Canada, 723, 723 National Environmental Policy Act (NEPA), 586National Hurricane Center, 691National Oceanic and Atmospheric Administration

(NOAA), 187, 702national parks, 560, 560, 584National Park Service, 561, 561 National Weather Service (NWS), 692, 698, 713natural events

changes in atmosphere and, 614changes in climate and, 734–738, 735, 742, 742 spread of pollution by, 601

natural features, 730, 731, 731 natural gas. See fossil fuels.natural processes, FL31, 601–603, 632, 635, 656, 656,

725 natural resources, 570, 575–577, 576, 588–591Nature Conservancy, 486, 562nature of matter

chemical properties, 86–89, 104, 115physical properties, 54, 81–86, 98–100, 103, 104potential energy, 115–116

nature of science, FL27, 5–31nautilus, 428nematocyst, 419, 419 nervous system, 213, 335, 352

of arthropods, 433of cephalopods, 428of cnidarians, 420 of worms, 423

nest parasitism, 547, 547 neurotoxins, 186neutrons, 748Newton, Sir Isaac, 137, 138, 138 newtons (n), 51, 149niche, 533, 556nimbostratus clouds, 663 nitrogen, 192, 224, 225, 613, 613 nitrogen cycle, 505, 505–506, 507, 524

effect on atmosphere, 614, 615 nitrogen-fixing bacteria, 266, 507, 507, 546, 554,

614, 615 nitrous oxides, 578, 630, 632 nocturnal animals, 294nonmetals, 769 nonpolar molecules, 227, 227 nonrenewable resources, 41, 120, 575, 576–577, 576 nonvascular plants, 383–384, 386 North America

average annual temperatures for, 720 El Niño and, 738tornado frequency in, 697–698, 697, 698

North Atlantic currents, 723 North Carolina, hurricane damage, 691 North Equatorial currents, 723 Northern Hemisphere

effects of global warming on, 739seasons in, 724–725temperatures in, 720, 720 wind patterns in, 650–652, 653, 654, 654

Norwegian ocean currents, 723 note-taking strategies, R45–R49

combination notes, 142, 142, 412, 412, 494, 494,644, 644, R45, R45

concept map, R49, R49 content frame, R45, R45 main idea and detail notes, 48, 48, 142, 142, 332, 332, 446, 446, 718, 718, R46, R46

main idea web, 4, 4, 80, 80, 142, 142, 190, 190, 254, 254, 446, 446, 680, 680, R46, R46

mind map, 110, 110, 142, 142, 374, 374, 446, 446,R47, R47

outline, 222, 222, 530, 530, R48, R48 supporting main ideas, 298, 298, 566, 566, 610, 610,R47, R47

Venn diagram, R49, R49 nuclear energy, 44, 113nuclear waste, 44nucleic acids, 224, 225, 225–226, 248, 248 nucleotides, 225–226, 225 nucleus, 202, 202, 203, 203, 204, 263, 279, 761

of an atom, 748

IND

EX

Index R95

in eukaryotic cells, 210function of, 205, 760 structure of, 257

nummulitids, 276

OOak Creek Marsh, 488 oasis, 499 objective results, 9, 9 objects

falling, 31, 31 forces acting on, 143, 146–147, 147 in motion, 147, 147 position of, 144speed and, 145, 145 work and, 149, 149

observations, 6, 7–8, 32, 32, R2, R4, R5accuracy of, 20, 20 evaluation of, 20–21, 21, 26–27, 26, 27 experimental bias and, 27–28objective, 9precision of, 18–19, 20 presentation of, 28, 29, 30, 30 qualitative, R2quantitative, R2records of, 24–25, R33senses and, 14–15, 14 variables and, 16–18

ocean currents, FL31, 723, 723, 736effect on temperature and precipitation, 719human activities and, 738movement of red tide and, 185role in El Niño events, 738

ocean ecosystems. See also marine biomes.abiotic factors, 498biotic factors, 496carbon cycle in, 504, 504 commensalism in, 545

oceansArctic, 739Atlantic, 689–690, 690, 723, 723 effect of global warming on, 740effect on climate, 721, 738hurricane formation over, 689–691Indian, 689Pacific, 689, 738pollution of, 589

octopus, 428, 428 oil. See fossil fuels.oil spills, 43 omnivores, 349open ocean biomes, 522–523, 523 operational definition, R31

qualitative, R31quantitative, R31

opiniondifference between fact and, 9, R9

orchids, 376, 376, 520, 545order, 310, 311, 312, 315

organ, 212, 212–213, 212, 334organelles, FL11, 202, 202, 204, 760

chloroplasts, 204, 205, 205, 219, 230, 230, 231, 378, 379, 760

endoplasmic reticulum, 204, 205–206, 760 of eukaryotes, 210functions of, 205–206, 230, 231, 232, 233, 234 Golgi apparatus, 204, 206, 760 lysosomes, 204, 206, 760 mitochondria, 204, 205, 205, 232, 233, 760 nucleus, 760 prokaryotes and, 209ribosomes, 760 vacuoles, 206, 241 vesicles, 204, 206, 760

organisms, FL29. See also animals; archaea; bacteria; fungi; living things; plants; reproduction.

abiotic factors and, 497–499, 497, 498 as biotic factors, 496building blocks of, 224changes in habitat and, 293, 580–582, 581, 582 characteristics of, 191–192, 257–258communities of, 534dependence on environment, FL12, 531diversity of, 255–256habitats of, 507, 532–533, 533 interactions of, 541–545, 542, 543, 544, 546,547, 556

levels of organization of, 534, 534, 535 multicellular, 210–211 (See also protists)needs of, 192, 193, 259niches of, 533organization of, 211–213, 212, 334–335pollution and, 578–580populations of, 532, 532, 534specialization of cells, 333survival characteristics, 289, 336, 337, 346, 354, 463, 466, 468, 474 (See also adaptation)

systems of, 350–351unicellular, FL11, 209–210, 209, 210. See also archaea; bacteria; protists.

organizationof ecosystems, 534, 535 of living things, FL29, 211–213, 212, 334–335, 534, 534, 535

of plants, 377, 377 organ systems, 212, 213, 334–335, 335, 352, 420, 752

of arthropods, 433, 437of birds, 466, 467 circulatory system, 335, 335, 423, 433, 437, 458of cnidarians, 419–420of crustaceans, 437digestive system, 335, 350, 422, 423, 433, 450excretory system, 422of mollusks, 426muscular system, 335, 352, 419, 423, 433, 448–449nervous system, 335, 352, 420, 423, 428, 433of plants, 377, 377 respiratory system, 335, 335, 351, 351, 457, 458, 466, 467

IND

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R96 McDougal Littell Science Grade 6

skeletal system, 352, 423, 447–448, 448, 451, 466, 467

of vertebrates, 447of worms, 422–423

osmosis, 241, 241, 248outer space, 22, 22, 612, 623, 737

density of atoms in, 60exploration of, 139

ovary, 398, 400, 400 oxygen

as abiotic factor, 496algae and, 550in the atmosphere, 613, 613 carbon cycle and, 504, 504–505, 504, 524, 614, 615,617, 617

cellular respiration and, 232, 233, 351, 763, 763 characteristics of, 223diffusion of, 238, 239, 240, 240 exercise and, 236forest fires and, 616gills and, 449, 449 lungs and, 458as material needed for life, FL29, 192, 224, 224,225, 259

molecular structure of, 58, 58, 617, 617 ozone and, 625, 632, 634photosynthesis and, 230, 231, 342, 378, 403, 762, 762

released by bacteria, 265structure of, 617, 617 in water, 550

oysters, 426ozone, 623, 625

absorption of radiation by, 625, 625 molecular structure of, 58, 58 as pollution in air, 630stratosphere and, 625, 625, 634–635, 635 troposphere and, 630

ozone layer, 43, 635, 638hole found in, 625, 634–635, 715, 715

ozone-oxygen cycle, 625, 632, 634

PPacific Ocean

El Niño and, 738storms in, 689

Pangaea, 736, 736 paramecium, 199, 210, 210, 280, 280 parasites, 265, 265

arthropods as, 437, 438protists, 277, 280relationship to host, 545, 547

parasitism, 545, 545, 546, 547, 556, 556 effect on populations, 551

particles, 91–92. See also atoms; molecules.arrangement of in solids, 70, 70 changes of state and, 90, 91, 92, 93, 93, 94, 94,95, 95

charged, 748, 749

ions, 39, 749in nucleus of atom, 139, 748in solid, liquid, and gas phases, 68–73and waves, 749

particulates, 630in the air, 636–637changes in climate and, 734cloud formation and, 661

passive transport, 238–241, 239, 240, 240, 241, 248Pasteur, Louis, 196–197, 197, 270pasteurization, 196patterns, FL27, 6, 23patterns of environment, 535, 536–537, 536, 537 patterns of natural events, 601–603, 724–725patterns of structure and function. See also classifica-

tion; protists.basic processes in cells, 203, 204, 205–206, 224–226, 229–230, 231, 232, 233, 234

characteristics of life, 191–192, 257–258life functions of organisms, 192, 211–213, 212 organization of organisms, 334–335in plants, 377–378, 377, 378, 379 properties of multicellular organisms, 210–211, 211 structure of cells, 225, 227, 227

penicillin, 361, 361 Penicillium, 358, 359, 361 percents, 159, 306, R41peregrine falcon, 586, 586 period, on periodic table, 768 periodic table of elements, 768–769 permafrost, 517permeable substances, 490perpetual-motion machine, 137, 137, 138, 139,

140–141 pesticides, 409, 562, 588, 630 petals, 400, 400 petroleum. See fossil fuels.phase change, 90–95, 104phloem, 377, 377, 379, 380phosphorus, 224, 225photography, 560photosynthesis, 230, 231, 234, 248, 248, 342, 378,

762, 762 by algae, 343, 382–383by bacteria, 265, 343in cacti, 380carbon cycle and, 504, 504, 614, 615 diffusion and, 239energy cycle and, 509Internet activity, 221necessities for, 498, 499products of, 403by protists, 278, 279, 343

photosynthetic pigments, 230, 231, 265, 279, 378phylum, 310, 310, 311, 312

table of, 755–758 physical changes, 84, 85, 104

changes of state, 90–95, 104chemical changes and, 86Internet activity, 79

IND

EX

Index R97

physical evidence, 303–304, 304 physical factors in ecosystems, 497–499, 497, 498, 499 physical properties, 81, 82, 104

change of state, 84, 90–95, 92, 93, 94, 95, 104density, 83, 89, 99, 99, 103electrical conductivity, 100of elements, 223heat conductivity, 100identifying substances by, 98–100, 104magnetism, 100, 100, 103mass, 49–51, 54–55, 57, 74, 82, 99measurement of, 54melting and freezing point, 91–92, 96, 103separation of mixtures by, 101–102, 103, 103 solubility, 100, 100 volume, 99

physical science, FL27, FL32–33and earth science, 103, 617life science and, 169, 462, 515, 552 unifying principles, FL33

physical states, 67, 74physics, FL32phytoplankton, 279, 509, 521, 522Pilobolus, 359, 359 Pinatubo, Mount, 734Pinchot, Gifford, 561pine trees, 344, 390, 391, 392pioneer species, 552, 554pistil, 398, 399, 400, 400 placenta, 476plankton, 279, 279Plantae, 317, 317, 318, 319, 320

characteristics of, 320, 376, 757–758 specialization of cells, 333

plant cells, 188–189, 229, 229, 230, 231 active transport and, 241–244basic processes in, 224, 229–230, 231, 232, 233, 234diffusion in, 238–240organelles of, 205–206, 760, 761 osmosis and, 241, 241 specialization of, 211structure of, 203, 203, 204, 205–206

plants, FL10, 256, 333, 392, 406, 533. See also photo-synthesis.

adaptations of, 343–344as autotrophs, 205bacteria and, 554as biotic factor in ecosystems, 496carbon cycle and, 614, 615, 617characteristics of, 320, 376defining of ecosystems by, 294dependence on environment, 531of desert and grassland biomes, 518–519diversity of, 372, 375–376, 376 effects of global warming on, 740of estuaries, 295, 522flowering, 397–398, 399, 400–404of forest biomes, 295, 520of freshwater biomes, 521global warming and, 740

growth of, 380, 381 interrelationships of, 541, 542, 544, 544, 545, 546 as invasive species, 581–582, 582 living space and, 551new discoveries, 371, 371 niches of, 533nitrogen cycle and, 505, 507, 614, 615 non-flowering, 390–391, 391, 392–393, 393 place in food web, 367 populations of, 532, 538, 550precipitation and, 725as producers, FL29, 341–342, 356, 364, 509, 512, 513, 514

products of, 403–404, 404 red tide and, 186reproduction of, 344, 384–386, 385, 387, 388–390, 389, 401–402, 401, 544

reshaping landscape, 403response to environment, 345, 345 seasonal changes and, 347, 347 seed producing, 390, 391, 392–393, 393 source of energy for, 224as source of medicines, 582specialization of cells, 211of still-water biomes, 522structural organization of, 211–213, 212, 377, 377 succession of, 552, 553–554, 553 in tundra and taiga biomes, 518viruses and, 274water cycle and, 614, 615

plate tectonics, 10–11, 10, 11point of view. See frame of reference.polar air mass, 682polar climate zone, 727, 728, 729 polar ice, 517 polar icecaps

expansion of in ice ages, 736–737, 737 fresh water in, 570

polar molecules, 226, 226, 240polar regions

air masses formed over, 682climate of, 727, 728, 729 jet streams and, 654, 654 solar radiation in, 619 temperatures near, 720, 720 wind circulation and, 651, 651, 653

pollen, 390, 390, 397, 398, 399, 400distribution of, 401 transportation of, 401

pollination, 390, 391, 399, 401–402, 544, 544, 570pollinators, 401–402pollutants, 630pollution, 560, 577, 577–580, 594

as acid rain, 672of air, 629–635, 641, 672attempts to reduce, 117attempts to reverse, 585–586, 588, 590–591control of, 631effects of, 631from fossil fuels, 43

IND

EX

R98 McDougal Littell Science Grade 6

oil spills, 592 red tide and, 185sources of, 295, 630 weather maps of, 704

polyps, 420, 420 pond ecosystems, 496, 496. See also freshwater

biomes.population density, 572populations, 532, 532, 556

birth rates, 555carrying capacity, 551, 568estimation of, 538–539growth and decline, 550–551, 550 of humans, 567–573, 568 interrelationships within, 533, 540–542as level of organization of environment, 534, 535 limiting factors, 549–554patterns in, 534, 536–537, 536, 537, 552–554

pore cells, 415, 415 position

reference point and, 144, 144 speed and, 145

potential energy, 114–116, 115, 115, 121, 132, 132,149, 149

change in form, 118change to and from kinetic energy, 119–120, 119,121, 122

of hurricane, 690simple machines and, 154–155, 155 of tropical storms, 690

prairie ecosystemsfire and, 484–485, 485–487Internet activity, 493

precipitate, 88precipitation, 503, 503, 659, 662, 672, 674

acid rain, 578, 578, 580climate and, 719, 727clouds and, 664in desert biomes, 518El Niño and, 738formation of, 668–669, 671 fronts and, 684global warming and, 739in grasslands, 519from hurricanes, 691measurement of, 669mountain effects on, 731, 731 oceans effect on, 722, 722 radar tracking of, 670, 672seasonal patterns, 725, 725 symbol for on weather maps, 702in temperate forests, 519in thunderstorms, 695in taiga biomes, 518in tropical forests, 520in tundra biomes, 517types of, 670water cycle and, 614, 615, 659, 659

precision, 18–19, 20, 32, 32, R22, R22 predator-prey interactions, 541, 543, 550, 551, 556

predators, 353, 353, 541arthropods as, 438, 439cooperation among, 543in desert biomes, 518echinoderms as, 429in grasslands, 519humans as, 294in tundra biomes, 517

prediction, 31, R3presentation of data, 28, 29, 30, 30 presentation of results, R34preservation of Everglades, 488–491pressure. See also air pressure.

boiling point and, 94volume and temperature of gases and, 73volume of gases and, 68

prey, 353, 541, 543primary consumers, 510, 510, 512, 513, 514, 514, 524,

551primary succession, 552–553, 552 principle of conservation of energy. See law of conser-

vation of energy.procedure, writing, R32producers, 265, 265, 509, 524

algae, 277energy cycle and, 509, 509, 510, 513, 514, 514 food chain and, 512place in food web, 367 plants, 341–342, 364, 376, 382succession and, 552–553, 552, 553, 554

prokaryotes, 209, 262–265, 321, 322, 322 prokaryotic cells, 202, 202, 216, 317, 317. See also

archaea; bacteria.properties of matter. See chemical properties; physical

properties.proportions, 89, R39propulsion, 39, 40protection of natural systems. See conservation.proteins, 224, 225, 248, 248

in cell membranes, 240, 240 production of, 205of viruses, 271, 272

Protista, 256, 317, 317, 318, 319, 321, 321 characteristics of, 755–756

protists, 210, 252, 276–281, 278, 282, 282 protons, 45, 748protozoans, 280, 280, 282, 282, 545pulley, 160, 162, 162–163, 162, 178 pumice, 25, 25 pupa, 436, 437 purple loosestrife, 581–582, 582 Pyramid Rover, 174, 175

Qqualitative information, 15qualitative observations, 24, 29, R2, R2 qualitative operational definitions, R31quantitative observations, 15, 20, 24, 29, R2, R2 quantitative operational definitions, R31

IND

EX

Index R99

questions, 6, 7extended response (ER), FL47–48on FCAT, FL35–48gridded response (GR), FL45multiple choice (MC), FL44short response (SR), FL46

Rradar stations, 701 radar tracking of weather, 670, 672, 691, 701, 701 radial symmetry, 421, 421, 429radiant energy, 749radiation, FL31, 619, 620, 620, 638

absorption by gases, 624–627, 625, 627 cloud cover and, 628, 628 trade winds and, 712used for heating homes, 129, 129

radula, 427rain. See also acid rain.

clouds associated with, 663, 664, 664, 673, 684, 691, 695

formation of, 668–669, 671 hurricanes as source of, 691measurement of, 669pollution and, 630, 670types of, 670water cycle and, 614, 615, 659

rain gauge, 669rain shadow, 731, 731 range, 18–19, 20, R37Rankin, William, 673rates, R38ratios, 159, R38records, 24, 32, R33recovery

of ecosystems, 486, 587 of endangered species, 586, 586

recycling, 590–591, 590 red tide, 184–187, 184, 185, 186, 187 reference point, 144, 144 reflection of solar radiation, 619, 619 relative humidity, 660, 666–667, 764, 764 remora, 545renewable resources, 41, 120, 575–576, 576, 589reproducible results, 9, 23, 26–27, 32reproduction

adaptation, 387 of amphibians, 457of arthropods, 433, 436asexual, 258, 258, 336, 339, 339, 357–358, 364, 386, 387, 416, 420, 423

of bacteria, 258, 258 binary fission, 258, 323of birds, 468–469budding, 358of cells, 195as characteristic of living things, FL29, 192, 258of cnidarians, 420, 420 of crustaceans, 437

effect on population, 550of ferns, 387of fish, 451–452, 452 of fungi, 357–358, 359of mammals, 476–477of mollusks, 426of mosses, 384–386, 385, 386 mutualism and, 544of plants, 388of reptiles, 458, 459seasons and, 347of seed plants, 388–390, 391, 397–398, 401of segmented worms, 423sexual, 338–339, 338, 339, 357, 364, 384–385, 386, 387, 416, 416, 420, 423, 435–436, 437, 451–452, 457

of slime molds, 280of sponges, 416, 416 spontaneous generation and, 196–197of viruses, 272, 273

reptiles, 453, 453, 454, 458, 458, 459, 460, 461,478, 478

adaptations of, 462, 462 body temperature of, 458characteristics of, 458–459

reservoirs, 491resource centers, FL21resources, 576

conservation of, 588–589natural, 570, 570, 575–577, 576, 588–591nonrenewable resources, 576–577, 576 renewable, 576, 576

respiration, 503, 503, 504, 504 respiratory system, 335, 351

of amphibians, 457of birds, 466, 467 of reptiles, 335, 458

responseto common stimuli, 192, 258to environment, FL29, 192, 258, 345–347, 345, 346,347, 352–353, 352, 353, 354, 364, 420, 423,424–425, 461, 463, 466, 468, 474

to gravity, 345to light, 346, 346 plants, 345, 345 to seasonal changes, 347, 354, 354 to touch, 345

resultsaccuracy of, 20, 20 evaluation of, 18–21, 26–27, 26, 27 experimental bias and, 27–28objective, 9precision of, 18–19, 19 presentation of, 23, 28, 29, 30, 30 reproducible, 9, 23, 26subjective, 9summarizing, R34

ribosomes, 204, 205, 760, 761 rivers, 521, 589RNA, 225–226robots, 174, 175, 370, 371

IND

EX

R100 McDougal Littell Science Grade 6

rockets, 39, 39, 43, 139for spacecraft, 39

root system, 377, 377, 386rotation of Earth, wind patterns and, 651–652, 651,

653, 686, 689roundworms, 423, 423, 758 run off, 486, 580, 580

Ssafety, R10–11, 752

animal, R11chemical, R11, R11 cleanup, R11directions, R10dress code, R10electrical, R11fire, R10glassware, R11heating, R10during hurricane weather, 691 during ice storms, 693 icons, R10–11 during lightning, 607for observing, 14sharp objects, R11during thunderstorms, 696 during tornadoes, 698

St. Helens, Mount, 578salamanders, 454, 455, 548, 548 salt, 242–243, 242 salt marshes, 294saltwater biomes, 521samples, R6sand dollar, 428, 429Sandoval, Christina, 315sand pine scrub habitat, 293, 293 satellites, 701, 714

images of weather from, 704, 704 monitoring ocean waters with, 187

saturation, 660scales, 47, 451, 458, 459, 459 scanning electron microscope (SEM), 201, 201 scanning tunneling microscope (STM), 60, 60, 173scatter plot graph, 26–27, 27, 29 scavengers, 510science, FL27

categories of, FL27international nature of, 601–603, 633–635, 650–651, 650, 651

life science, FL28–29nature of, 5–31processes of, 6, 7 unifying principles, FL31unifying principles of, FL27, FL29

Science ethics,752–753Science on the Job

architect, 726textile designer, 228urban planner, 574, 574 wildlife photographer, 355

Scientific American FrontiersChilling Changes, 290, 290 Dust in the Air, 602, 602 Ecosystems on Fire, 486, 486 Fuels of the Future, 40, 40

scientific bias, R6scientific inquiry, 7–8

evaluating results, 18–21, 19, 20, 21, 26–27, 26, 27

identifying bias, 27measurements and, 15–16patterns in, 23presentation of results, 28, 29, 30, 30 purpose of, 31records of, 24–25senses and, 14–15variables and, 16–18, 18

scientific notation, 207, R44scientific processes, 32, 32

ask questions, 6–7, 7 determining what is known, 6–8, 7 interpreting results, 6, 7, 8, 26–28investigate, 6, 7, 8, 23–25sharing results, 6–7, 7, 28, 29, 30

scientific theory, 196scientists, 5

checking results, 26–27, 26, 27 experimental bias and, 27habits of mind, 6, FL26identifying and controlling variables, 16–18Internet activity, 3looking for patterns, 23observation with senses, 14–15, 14, 32presentation of results, 28, 29, 30, 30 processes used, 6, 7, FL27record keeping, 24, 32use of tools and instruments, 15workplaces of, 5

scorpions, 438screw, 160, 165, 165, 181, 181 scrub jay, 293, 293 SCUBA diving, 370, 370 sea anemone, 418, 421, 421 sea breezes, 655, 655, 695, 695, 730sea cucumbers, 429sea fans, 602, 602 sea level, 621, 740seaside sparrows, 295seasons, 724

animal responses to, 354, 354 change in winds, 656, 656 changes as part of climate, 724–725, 724, 725 ozone layer and, 635plant responses to, 347

sea stars, 429, 430, 431sea urchins, 429, 429 seaweed, 277, 278, 278, 321, 321, 509 secondary consumers, 510, 510, 512, 513, 514, 514,

524, 551secondary succession, 553, 553 sedimentary rock, 750

IND

EX

Index R101

seed coat, 388, 389 seeds, 388, 391, 392, 398, 406, 406

of angiosperms, 397–398, 399, 400–404, 402 distribution of, 402–403, 402, 544germination of, 394–395, 398of gymnosperms, 390, 391, 392Internet activity, 373mutualism and, 544production of, 388, 389, 390, 397–398, 399 spores and, 389 survival of, 396

segmented worms, 422–423, 422, 423, 758 seismograph, 21 semiarid subclimate, 728 senses, scientific observations, 14–15sensory organs

of amphibians, 457of birds, 466of fish, 449of reptiles, 458

sepals, 400, 400 sessile, 415sexual reproduction, 338, 338–339, 338, 339, 364

of amphibians, 457of angiosperms, 397–398, 399 of arthropods, 433of cnidarians, 420of ferns, 387of fish, 451of fungi, 358genetic diversity and, 386of gymnosperms, 390, 391, 398of mammals, 476–477of mosses, 384–385, 385 of reptiles, 459of seed plants, 388, 391 of segmented worms, 423of sponges, 416

shapegases and, 68liquids and, 68, 71as physical property, 82, 82 of solids, 68, 70

sharing ideas, 5, 6, 7 sharks, 452, 545shells, 23, 427, 428, 429, 429. See also eggs.Shinn, Gene, 602ships

collection of weather data by, 701, 701 use of wind patterns, 654, 712, 712

Shirley, Marlon, 169shoot systems, 377, 377, 380–381, 381 short-response questions (SR), FL35, FL46, FL46shrimp, 437Sierra Club, 561, 561 significant figures, R44Silent Spring (Carson), 562, 585simple machines, 151–152, 152, 160, 176, 178

change direction of force, 153, 161, 161, 162, 162 change size and distance of force, 152, 161, 161,162, 162, 163, 163, 164

combinations of, 170–171efficiency of, 156–158, 159inclined plane, 154–155, 155, 160, 164–165, 164, 165

lever, 160, 161, 161 mechanical advantage, 153, 163, 166–168pulley, 160, 162–163, 162, 163 real-world examples of, 152screws, 160, 165, 165, 181, 181 transfer of energy, 154–155wedge, 160, 164–165, 164 wheel and axle, 160, 162, 162, 165

single-celled organisms. See unicellular organisms.siphon, 428SI units, 16, 22, R20–21skeletal system, 352

of birds, 466, 467 of bony fish, 451of cartilaginous fish, 451of vertebrates, 447–448, 448

skeletonof echinoderms, 429endoskeleton, 447, 466, 467, 478, 481, 481 exoskeleton, 433, 433

skeptical mind, FL26, 6, 7, 26sleet, 670, 671 slide preparation, 200, 201slides, making, R15, R15 slime molds, 277, 278, 281, 281, 282 Smith, Garriet, 602smog, 117, 630snails, 426snakes, 454snow, 669, 670, 670, 671

architecture and, 726blizzards, 692fresh water in, 570

snow line, 721 social behaviors, 353sodium borohydride, 45soil

as abiotic factor, 294, 496, 498–499, 498 characteristics of in different ecosystems, 500–501formation of, 552–553, 552, 554as limiting factor, 550, 551nitrogen cycle and, 505, 614, 615 pollution of, 577

solar-car racing, 40, 40, 41solar cells, 41, 126, 128, 128, 132, 132

advantages and disadvantages of, 128–129solar eclipse, 751, 751 solar energy, 40, 41, 126–129

advantages and disadvantages of, 44, 45conversion to chemical energy, FL29, 118conversion to electrical energy, 128–129, 128,589, 589

conversion to thermal energy, 129, 129 Solar Energy Center, 45solar radiation, 618–621, 619, 619, 620, 638, 749

absorption by gases, 624–627, 625, 627 cloud cover and, 628, 628

IND

EX

R102 McDougal Littell Science Grade 6

trade winds and, 712used for heating homes, 129, 129

solar sails, 40, 40 solar system, 750, 751, 750–751 solids, 68, 68, 90

behavior of, 68, 69, 70melting and freezing, 91–92, 91, 92 as sign of chemical change, 88sublimation of, 93

solubility, 100solutions, finding, 117sound energy, 49, 113, 113, 120, 122sound waves, 606South America, 738space, 192, 551

matter and, 49patterns in, 536, 536 as requirement for life, 192, 193volume as, 51

spacecraft, 38–39, 39–41, 139space objects, 735space program, 43SpaceShipOne, 22, 22 spacesuit, 139, 215, 215 specialization, 208, 211, 212, 216, 333, 334. See also

adaptation.of plants, 377, 378, 378 of sponges, 415

species, FL29, 310, 310, 311, 312, 376, 531, 561, 561 competition between and among, 541–542discovery of new, 370, 370, 371, 371 endangered, 355, 355, 489, 563, 586, 586 extinct, 371, 396, 735extinction, FL29naming of, 307–309threatened, 294, 489

spectrometers, 187speed, 114, 114, 145, 145, 145

equation for, 754forces and, 147, 147

sperm, 398, 452. See also pollen; sexual reproduction.of ferns, 387of fish, 451of fungi, 451of mosses, 385of plants, 390, 390, 397, 398, 399, 400

spicules, 416spiders, 438spinal cord, 447spinnerets, 438, 438 spiracles, 351, 351, 438sponges, 211, 414–416, 415, 415, 440, 440, 758 spontaneous generation, 196–197, 197 spores, 357, 357, 387

in dust, 602–603, 602 of ferns, 387of fungi, 357–358of mosses, 384–385, 385 seeds and, 389, 389 of slim molds, 280

spring. See seasons.squids, 428stamen, 400, 400 standards, FL34Stanley, Mount (Uganda), 721starch, 224, 230, 230, 232, 343, 343, 380, 762–763states of matter, 67, 67–73, 104

changes in, 84, 90–95water cycle and, 503

static electricity, 605, 748stationary fronts, 684, 685 station symbols, 702, 702, 766, 766 steam engines, 137Steidinger, Karen, 185, 185 stem systems, 377, 377

soft and woody, 380–381, 381 stigma, 400, 400 still-water biomes, 522, 522 stimulus, 345, 345, 352, 352 stinging cells, 419 stomata, 378, 378, 379, 380Storey, Ken, 290, 291storms

dust, 601–603, 601, 602, 613, 616, 616 El Niño and, R7, R7 ice, 693, 693 lake-effect snowstorms, 692thunderstorms, 694, 694–698, 695, 696, 708tropical storms, 689, 690, 690

storm surge, 691strands, FL34strangler fig, 541, 541, 559stratosphere, 622, 623, 638

ozone layer of, 625, 625, 634–635, 635 volcanic eruptions and, 734–735

stratus clouds, 662, 663, 664, 664 stretching, 116strong force, 139subarctic subclimate, 728, 729 subclimates, 728, 728, 742, 742 subjective results, 9, 9 sublimation, 93submersibles, 370substances, 67

atoms and, 56changes of state and, 90–95chemical changes, 86–88chemical properties, 86–88identification of, 98–102molecules as, 58physical properties, 81–85, 89, 103pure and mixed, 61–65, 62, 66, 74states of, 67–73

suburbs, 573, 573 succession, 486, 486, 487, 552, 552–554, 552, 553 sugar, FL8, 224, 230

carbon cycle and, 504, 504 cell growth and, 205cellular respiration and, 232chemical structure of, 224

IND

EX

Index R103

energy cycle and, 509energy stored in, 205, 224, 229passive transport of, 240, 240 photosynthesis of, 230, 762, 762 production of, 341–342, 378, 382, 403storage of, 380

sulfur, 225sulfur dioxide, 578, 630summer. See seasons.Sun. See also solar system.

absorption of radiation by gases, 624–627, 625,627, 628

as alternative energy source, 40, 41energy from, 618–621, 622, 623, 638as energy source for life, 498, 507formation of winds and, 650, 650 gravity and, FL33particulates blocking radiation of, 734photosynthesis and, FL29, 229–230, 762, 762 radiation and, 619–620, 619, 626as renewable resource, 576temperature and angle of rays of, 720, 724, 724

sunburn, 625sunlight. See light; Sun.Sunshine State Benchmarks, FL34, FL35, FL36–44Sunshine State Standards. See also FCAT Practice.

benchmarks, FL36–44identification in lessons, FL35organization of, FL34practice questions, FL35–48, FL35

Superfund Program, 586, 588, 588 survey, R6survival. See also adaptations.

of seeds, 396sustainable practices, 588, 588–591swamps, 293, 294, 295, 295 swim bladder, 449, 449 symbiosis, 483, 544, 556, 556, 559

commensalisms, 545, 545, 546 mutualism, 544–545, 544, 546 parasitism, 546, 547, 547

symmetry, 417, 417, 421, 421, 422

Ttaiga biome, 517, 518, 518 taxonomy, 300, 302

binomial nomenclature, 308–309, 309 changes in, 316–317tools used for, 304

technology. See also machines.catapults, 136, 136 changes in taxonomy and, 317complicated machines, 170–175, 178, 178 computer modeling, 139, 214, 214, 715, 715 computer study of cells, 200computer study of DNA, 304conservation tillage, 588efficient cars, 40, 41, 117, 127, 128, 157, 578, 630energy conversions and, 126–129, 132

energy sources and, 589, 589 exploration of outer space, 139, 139 global information systems, 562global warming and, 634harnessing wind power, 130, 130 light-emitting diodes, 126, 127 mass transit, 590, 590 to measure air pressure, 712, 712 microscopes, 60, 60, 173, 188, 194, 194, 198–199, 198, 200–201, 276, 299, 317, 369, 369, 759, 759

microtechnology and nanotechnology, 172–173, 173

for navigation, 368nonrenewable resources and, 576–577photography, 560to power cars, 40, 40, 41, 117, 127, 127, 128predictions by computers, 633, 705robots, 174, 175, 370, 371satellites, 187scanning electron microscope (SEM), 201, 201 scanning tunneling microscope (STM), 60, 60, 173simple machines, 151–157solar cells, 128–129, 128 for space travel, 39–41, 139spectrometers, 187steam engines, 137for study of cells, 188, 194, 194, 198–199, 198,200–201, 201, 216

submersibles, 370, 371uses for machines, 172–173waste disposal, 590–591, 590 for weather forecasting, 670, 700–705, 708, 708, 714

teeth, 473telecommuting, 590telegraph, 713, 713 temperate forest biome, 517, 519–520, 520 temperate rain forests, 520temperature

as abiotic factor in ecosystems, 497of air masses, 681–682, 682 altitude and, 721, 721 around cities, 730atmospheric layers of, 621, 622, 638atmospheric particulates and, 734–735change, 748climate and, 719, 727convection and, 621, 621 of desert and grassland biomes, 518effect of change in position and motion of atoms, 73, 91–92, 93, 94, 95, 748

El Niño and, 738formation of clouds and, 661, 661 global warming and, 739greenhouse gases and, 626, 632, 633–634, 633 growth of bacteria and, 285 humidity and, 659, 659, 660latitude and, 720, 720 as limiting factor in ecosystems, 551oceans’ effect on, 722, 722

IND

EX

R104 McDougal Littell Science Grade 6

patterns of and monsoons and wind, 655, 655 seasonal patterns, 724, 724 as sign of chemical change, 88of taiga and tundra biomes, 517, 518of temperate forest and tropical forest biomes, 520tropical storm formation and, 690unit conversions, R21units of measurement for, 15, 15 volume and pressure of gases and, 68, 73, 73, 77 water cycle and, 507weather maps of, 704, 704 wind formation and, 649–650, 654

tentacle, 418tertiary consumers, 510, 512, 513, 514, 514 theory, 10, 196

changes in, 11hypothesis and, 9–10

thermal energy, 113, 113, 120, 126, 127. See also heat.thermometers, 15, 15 thermophiles, 264, 264 thermosphere, 622, 623, 638Think Science

evaluating conclusions, 431finding solutions, 117hypothesis testing, 699inferring, 548making comparisons, 215

thunder, 606thunderstorms, 694, 694–698, 696, 708

effects of, 696in Florida, 604, 605, 695formation of, 695, 695

ticks, 438tidal pools, 522tides, 751, 751time

distance, speed and, 145, 145 patterns in, 537, 537

Timelines in Scienceatmosphere, 712–715biodiversity, 368–371conservation, 560–563understanding forces, 136–139

tissue, 211, 211–213, 212, 334of cnidarians, 419

toads, 454tools, 712. See also technology.

balances, 50, 54, 54 barometer, 648, 648, 712, 712 dichotomous key, 312, 313 Doppler radar, 670, 702field guides, 314microscopes, 188, 194, 194, 198–199, 198, 200–201, 201, 216, 276, 299, 317, 369, 369

for observing, 15of oceanographers, 187rain gauge, 669scales, 51scanning electron microscope (SEM), 200, 201 scanning tunneling microscope (STM), 60, 60 of scientists, FL27

for weather forecasting, 701, 701, 713, 713,714, 714

tornadoes, 691, 697, 697–698, 697, 698, 708, 767, 767 tourism, 186toxins, 361, 515, 515, 536, 541trade winds, 652, 653

effect on travel, 654movement of hurricanes and, 690sailors’ use of, 712, 712

traits, 302transfer of energy, 149, 149 transmission electron microscope (TEM), 201, 201 transpiration, 378, 380, 392, 503, 503 transport, 248

active transport, 241–244, 242, 242, 243, 248and cell size and shape, 244–245, 245 endocytosis and exocytosis, 243, 243 passive (diffusion), 238, 238–242, 239, 246–247, 248

trash, 569, 569, 579tree line, 721 trees, 344, 381

acid rain and, 672, 672 commensal relationships of, 545, 546 competitive relationships of, 541coniferous, 390, 391, 392–393, 393 deciduous, 397, 397–398, 399, 400–404need of water, 499reproduction of, 390, 391, 399 shoot system of, 381

trials, 18, 18Chapter Investigation, 12–13, 12 multiple, 21

trough, of wave, 749tropical air mass, 682tropical forest biome, 517, 520, 520 tropical hardwood hammocks, 294tropical rainforests, 497, 499, 520tropical storms, 689, 690, 690 tropical wet and dry subclimate, 728, 728 tropical wet subclimate, 293, 728, 728 troposphere, 599, 622, 623, 638

cloud formations in, 662greenhouse gases in, 626jets streams in, 654, 654 ozone in, 630warming of, 721trough, of wave, 749

Truman, Harry, 490tube feet, 430, 430 tulipomania, 275tundra biome, 517, 517, 518 tundra subclimate, 728, 729 turtles, 186, 453, 453, 454, 460 typhoons, 689–691, 690

Uultraviolet radiation, 625, 625

absorption and reflection of, 624, 625, 625 skin cancer and, 625

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Index R105

uncontrolled variables, 12, 21underground water storage, 490unicellular organisms, FL11, 193, 193, 199, 208–209,

216. See also bacteria.archaea, 209, 209, 264, 267, 318, 319, 321characteristics of, 257–258classification of, 219functions of, 333microorganisms, 256photosynthesis of, 343prokaryotic cells, 202, 202 protists, 210, 210, 252, 276–281, 278, 321reproduction of, 336yeast, 359, 359

unifying principlesof earth science, FL31of life science, FL29of physical science, FL33

United Nations Environment Programme, 588Unit Projects, 41, 291, 487, 603units of measure, 15, R20–21

centimeter (cm), 52, 754changing metric to U. S., R21changing metric units, R20checking, 20conversion of, 22degree (º), 15for density, 83gram (g), 50, 754hertz (Hz), 754International System (SI) of units, 16, 22joule (J), 149, 156, 754kilogram (kg), 50, 754kilometers per hour (k/h), 145liter (L) and milliliter (mL), 53meters (m), 22, 149, 754meters per second (m/s), 145micrometer, 200miles per hour (m/h), 145millibar, 703, 703 newton (N), 51, 149, 754pound (lb), 51second (s), 754for volume, 82

universe, FL30, FL31University of Central Florida, 45updrafts, 599, 694–698, 695, 708, 708 urban areas

air pollution around, 630–631, 630, 631 biodiversity and, 295growth of, 572–573, 572, 573, 574, 574

urban heat island, 730U.S. Division of Forestry, 561, 589

Vvaccinations, 196, 267vacuoles, 206, 241 valley breezes, 655variables, 16, 16, R29, R30

controlling, R17dependent, R30independent, R30uncontrolled, 21

vascular plants, 386 ferns, horsetails, club mosses, 386in Florida, 293seed-producing, 388–390, 391, 392–393, 396, 397–398, 399, 400–404

vascular system, 377of echinoderms, 430of ferns, 386of plants, 377, 378, 379, 380

Venus flytrap, 344, 344 vertebrae, 447, 448, 449

in birds, 467 in fish, 449 in mammals, 475

vertebrates, 444, 444–445, 447, 478, 758 adaptation to land, 454–455amphibians, 454–455, 456, 457, 460–461, 462birds, 463–466, 464, 465, 467, 468–469, 468,469, 470

characteristics of, 447–448fish, 448–452, 449 in Florida, 293mammals, 472–477, 472, 473, 475, 476, 477 reptiles, 454, 458–461, 458, 459, 460, 461, 462, 462

vesicles, 204, 206, 760, 761 vibration

of atoms and molecules, 59, 68, 69, 70, 91as unwanted energy conversion, 123

viruses, 252, 260, 260, 272, 282, 282 animal cells and, 260, 260 bacteria and, 263, 270, 272, 273 characteristics of, 270–272diseases caused by, 272, 272, 274, 274, 275plants and, 275replication of, 273

visible lightabsorption and reflection of, 625, 625, 626atmospheric effects on, 624energy of, 625lasers and, 40ozone layer and, 625radiation of, 618–619reflection and absorption of, 619 satellite images of, 704, 704

vocabulary strategies, 412, 412, 718, 718, R50–51description wheel, 254, 254, 298, 298, 412, 412,644, 644, R50, R50

four square, 48, 48, 190, 190, 332, 332, 412, 530, 530, R50, R50

frame game, 110, 110, 494, 494, 610, 610, R51, R51 magnet word, 4, 4, 80, 80, 446, 446, 566, 566,R51, R51

word triangle, 142, 142, 222, 222, 374, 374, 412, 680, 680, R51, R51

volcanic eruptions, 11, 552, 578, 616, 630, 632, 734–735, 735

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R106 McDougal Littell Science Grade 6

volume, 51, 74formula for, R43, R43 of gases, 68, 72, 72, 73, 90liquids and, 68, 71, 90mass, density and, 83, 89mass and, 54–55measurement of, 52–53, 53, 54–55as physical property, 82solids and, 68, 70, 90temperature and pressure of gases and, 73, 77

volvox, 199, 279

WWallace, Alfred Russell, 369warblers, 547, 547 warm fronts, 684, 685 waste

disposal, 569, 569 reducing, 590–591, 590

wateras abiotic factor, 496, 499in air masses, 682 air masses and, 682animal reproduction and, 416, 420in the atmosphere, 613, 633, 658–661, 659, 660,661, 668–670, 671, 672, 674

biomes of, 521–523boiling point of, 94cellular respiration and, 232, 233, 499, 763, 763 cellular transportation of, 241chemical structure of, 224, 226, 226 effect on temperature and precipitation, 719energy cycle and, 509form of snowflake, 70 form of solid phase, 70germination and, 389as greenhouse gas, 626for humans’ use, 569, 570–571, 583as limiting factor in ecosystems, 551as material needed by living things, FL29, 192, 226, 226, 259

melting and freezing point of, 91molecular structure of, 58, 58, 62osmosis and, 241, 241, 248photosynthesis and, 230, 231, 342, 378, 499, 762, 762

plant reproduction and, 385, 387pollution of, 577, 579, 579, 580, 580, 585, 586as renewable resource, 576reproduction and, 384–385, 389soil structure and, 499as source of hydrogen, 44states of, 67, 68, 70 structure of, 224, 226, 226, 503transport of in plants, 377, 377 treatment plants for, 102, 102, 563

water cycle, FL31, 503, 503, 524, 659, 659 effect on atmosphere, 614, 615 temperature and, 507

water displacement method (volume), 53, 53,54–55, 107

water ecosystems, 499. See also aquatic biomes.water mold, 280water pollution, 185water quality, 293, 579, 579, 580, 580 Water Resources Development Act, 490watersheds, 563, 571water vascular system, 430Watson, James, 214Watt, James, 138wavelength, 749, 749, 754waves, FL31, 18, 18, 149, 749, 749

and particles, 749weather, FL16, FL17, 642, 649, 673, 678, 682,

689–693, 708climate and, 719clouds and, 662, 664at doldrums, 652effects of, 699fronts and, 684, 685, 688high-pressure systems and, 686, 686 in horse latitudes, 652hurricanes, 689–690, 690, 691 jet streams and, 654low-pressure systems and, 687, 687, 689–693movement of, 713patterns of heating and cooling and, 655pollution and, 631severe storms and, 699technology for forecasting, 700–705telegraphing forecasts, 713thunderstorms, 694–698, 695, 696 tornadoes, 697–698, 698 as uncontrolled variable, 18wind belts and, 652winter storms, 691–695

weather balloons, 701, 701, 714weather buoys, 701, 701 weather center, 706–707weather data

collection, 700–701, 701 display of, 702–704, 702, 705, 711, 711

weatheringchemical, 750mechanical, 750

weather maps, 702–704, 702, 705, 711, 711 weather safety, 679, 691, 693, 696, 698 weather systems, 686–687, 686 wedge, 160, 164Wegener, Alfred, 9–10weight, 51westerlies, 652, 653 West Indian Manatee, 292, 293, 294wetlands, 496, 496, 512, 513, 587

in Florida, 294, 295, 295 food chain and food web and, 512, 513 invasive species in, 581–582, 582 recovery of, 488–491

wet mount, making, R15, R15

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Index R107

whales, 543wheel and axle, 160, 162, 162, 167, 167, 178 wind, 649

belts of, 652, 653 clouds and, 662, 664Coriolis effect and, 651, 651 effects on travel, 654, 657, 657 as energy source, 44, 45, 112, 130, 130, 589formation of, 650, 650 formation of tornadoes and, 697generation of electricity from, 128, 128, 130global winds, 650–652, 653, 654Internet activity, 643jet streams, 654, 654 as limiting factor, 551monsoons, 656movement of red tide and, 185speeds, 765, 765 spread of pollution by, 600–601, 601–603, 629, 630thunderstorms and, 696uneven heating and, FL31, 649–650, 655–656, 655, 656

weather maps of, 704wings, 466, 467 winter. See seasons.Winter, Steve, 355

Woese, Carl, 370wolves, 510, 519

competition among, 542population patterns, 550, 550

wood frogs, 290, 456 woody plants, 381. See also coniferous trees; trees.work, 149, 149

force, motion and, 149, 150formula for, 754machines and, 151–157output and input, 156transfer of energy and, 154–155, 155

World Solar Challenge, 41worms, 414, 418, 422–425, 422, 423, 440, 440

Xx-rays, 113xylem, 377, 377, 379, 380, 381

Y, Zyeast, 322, 358, 359, 359, 362–363

fermentation by, 235Yellowstone National Park, 560, 560, 584

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