Question

in plants, water is pulled by other water molecules up the stem of the plant. which property of water does this demonstrate?
a. cohesive behavior because water molecules are sticking together.
b. ability to moderate temperature because heat is needed to move water up the stem.
c. expansion upon freezing because water molecules expand as they move up the stem.
d. versatility as a solvent because water molecules are dissolving as they move up the stem.
why is this property important to sustaining plant life on earth?

Explanation:

First Question (Multiple Choice)

To solve the first question, we analyze each option:

• Option A: Cohesive behavior refers to water molecules sticking to each other. In plants, when water is pulled up the stem, it's because water molecules stick together (cohesion), allowing them to be pulled along.
• Option B: The ability to moderate temperature is about water's heat - absorbing and - releasing properties, not related to water moving up the stem.
• Option C: Expansion upon freezing is about water's volume change when it freezes, not relevant to water transport in plants.
• Option D: Versatility as a solvent is about water dissolving substances, not about water movement in plants.

So the correct option is A.

This property (cohesion) is important for sustaining plant life because plants need to transport water from their roots to other parts (like leaves) against gravity. Cohesion allows water molecules to form a continuous column in the xylem (the plant's water - conducting tissue). As water evaporates from the leaves (transpiration), the cohesive forces between water molecules pull the entire column of water up from the roots. This water transport is essential for photosynthesis (as water is a reactant), for maintaining turgor pressure in plant cells (which helps with structure and growth), and for transporting nutrients dissolved in water throughout the plant.

Answer:

A. Cohesive behavior because water molecules are sticking together.

Second Question (Explanation)