Lesson 1 TYPES OF GREEN PLANTS 1
Reading Material：PLANTS 12
Lesson 2 POLLINATION 18
Reading Material：THE STORY OF A CATTAIL SEED 27
Lesson 3 BACTERIA 33
Reading Material：BUGS AND US 44
Lesson 4 BIOLOGICAL CONTROL 52
Reading Material：WHAT IS AN INSECT？ 63
Lesson 5 BEES-SOLITARY，PARASITIC AND SOCIAL 71
Reading Material：HIVE-BEES-THE MOST FAMOUS POLLINATORS 84
Lesson 6 ANIMAL BEHAVIOUR 91
Reading Material：HOW ANIMALS PROTECT THEMSELVES 104
Lesson 7 WHAT IS LIFE？ 112
Reading Material：THE LIVING AND THE LIFELESS 125
Lesson 8 PROTEINS 131
Reading Material：THE PROTEINS 143
Lesson 9 THE STRUCTURE AND FUNCTIONS OF LIVING THINGS 153
Reading Material：THE CELL THEORY 163
Lesson 10 ENZYME ACTION 169
Reading Material：ENZYMES 181
Lesson 11 THE VARIETY OF LIFE 188
Reading Material：DIVISION INTO SPECIES AND CLASSIFICATION 201
Lesson 12 FUNGI-FRIENDS AND FOES 208
Reading Material：THE STORY OF A MUSHROOM 221
Lesson 13 THE GROWTH OF PLANTS 226
Reading Material：THE CONTINUITY OF LIFE 237
Lesson 14 CHLOROPHYLL AND PHOTOSYNTHESIS 246
Reading Material：THE PROCESS OF PHOTOSYNTHESIS 257
Lesson 15 MENDEL AND THE BEGINNING OF GENETICS 263
Reading Material：VARIATION 277
Lesson 16 DNA-THE MOLECULE OF LIFE 283
Reading Material：DNA：THE HEREDITARY MATERIAL 293
Lesson 17 DARWIN‘S THEORY OF NATURAL SELECTION 298
Reading Material：ADAPTATION OF ANIMALS TO HEAT AND COLD 308
Lesson 18 RECYCLING IN NATURE 316
Reading Material：THE NITROGEN CYCLE 329
Lesson 19 THE FLOW OF ENERGY THROUGH THE FOOD CHAIN 337
Reading Material：ENERGY FLOW AND FOOD CHAINS 350
Lesson 20 THE DANGER OF CHEMICAL INSECTICIDES 357
Reading Material：WATER POLLUTION 369
Lesson 21 LIVING IN A DARK SEA OF SMOG 376
Reading Material：AIR POLLUTION，WEATHER AND CLIMATE 387
Lesson 22 THE SCIENCE THAT IMITATES NATURE S MECHANISMS 394
Reading Material：LIVING LIGHT 409
SUPPLEMENTARY READINGS： 419
1．THE FROG’S LIFE CYCLE 419
2．TYPES OF ANIMALS -THE VERTEBRATES 423
3．TYPES OF ANIMALS-THE INVERTEBRATES 427
4．TOO MUCH KILLING 431
5．INSECT IN ARMOUR-BEETLES 435
6．CIRCULATORY SYSTEM 441
7．A JEWEL FISH FACES AN UNUSUAL PROBLEM 445
8．HUNTING THE OCTOPUS IN THE GILBERT ISLANDS 449
9．FIGHTING FISH 453
10．HOW DO PROBLEMS ORIGINATE FOR YOUR EXPERIMENT？ 456
11．CHEMICALS IN CROP PRODUCTION 460
12．FOOD FROM THE SEA 466
VOCABULARY 472