EXERCISE PAGE 



75. Can the roots and stump of a plant force water upward ? 106 



76. How does a plant absorb water ? 107 



77. What are root hairs ? ...*.... 109 



78. What is the path of water in plant stems ? Ill 



79. ' What food materials are present in plants ? ....112 



80. Is starch soluble in water ? 114 



81. Can starch be digested (changed into a soluble substance) outside the body of a plant or animal ? 115 



82. How is food distributed through the human body ? the flow of blood in the veins .... 117 



83. The flow of blood in the arteries 118 



84. Of what does the blood consist ? 119 



85. How does the blood circulate through the capillaries ? 120 



86. What are the values of different kinds of foods ? 121 



87. What are the stages in the development of the frog's egg ? 122 



88. The growth and development of a tadpole 124 



88 A. The development of the bird embryo during the hatching of the egg 125 



89. The structure of a seed and of the young plant ..126 



90. How rapidly may plants and animals increase under entirely favorable conditions ? .... 127 



91. How do ears of corn differ in the number of grains they have ? 129 



92. How do ears of corn differ in weight ? 130 



93. What is the relation between the weight of the grains and that of the cob in ears of corn ? . . 131 



94. Are variations in parents transmitted to offspring ? 133 



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