2.6 Summary 2.6.1 Underline the correct term: 1. In a solution of sugar in water: a. sugar is the solute/solvent b. water is the solute/solvent Quiz 2. Which statement is true? a. All reactions must have water to take place. b. In living cells water prevents chemical reactions from taking place. C. Many chemical reactions require the presence of water to take place. d. Water is useful in chemical reactions in the cell because it is a poor solvent. 3. Write "True' or 'False' after each statement. a. Only water molecules diffuse. __ b. Osmosis refers to the movement of solute particles. __ C. Diffusion can only take place through a semipermeable membrane. __ d. Osmosis is the diffusion of water through a semipermeable membrane. __ e. Semi-permeable membranes allow some things to pass through them but not others. __ f. Cell membranes are semi-permeable. __ 4. Fill in the blanks in the following passage. Large animals have a (A) __ surface area than small animals. They occupy more space and SO have a larger (B) __ than small animal But large animals have a (C) __ surface area:volume ratio than small animals. A small organism may absorb oxygen from its surroundings by (D) __ over its whole body But large organisms usually have ty mechanisms to obtain a quick supply of oxygen. 5. Choose the correct answer: 1. The Xylem: A. is found only in the stem

## Step 1<br />In a solution of sugar in water, the solute is the substance that is dissolved the solvent is the substance that does the dissolving. Here, sugar is the solute and water is the solvent.<br /><br />## Step 2<br />The statement "Many chemical reactions require the presence of water to take place" is true. Water is often referred to as the "universal solvent" because it can dissolve many substances. It is also a crucial component in many biochemical reactions.<br /><br />## Step 3<br />The statements about diffusion and osmosis are evaluated as follows:<br />a. Not only water molecules diffuse, but also other small molecules.<br />b. Osmosis refers to the movement of solvent particles, not solute particles.<br />c. Diffusion can take place through any permeable medium, not just a semipermeable membrane.<br />d. Osmosis is indeed the diffusion of water through a semipermeablee. Semi-permeable membranes do allow some substances to pass through while blocking others.<br />f. Cell membranes are indeed semi-permeable.<br /><br />## Step 4<br />The passage discusses the relationship between the size of an animal and its surface area to volume ratio. Large animals have a smaller surface area to volume ratio than small animals. A small organism may absorb oxygen from its surroundings by diffusion over its whole body. However, large organisms usually have specialized mechanisms to obtain a quick supply of oxygen.<br /><br />## Step 5<br />The xylem is a type of tissue in vascular plants that conducts water and dissolved nutrients. It is found in the stem and roots of the plant.