Question

to function properly, a cell must maintain an optimal water balance. cell membranes are permeable to water, so a cells water balance is affected by its surroundings. water molecules pass through the cell membrane via a process known as osmosis. this video shows water molecules crossing the cell membrane via osmosis. complete the paragraph. at the start of the video, there is a concentration of water molecules inside the cell than outside the cell. the water molecules cross the cell membrane in. water molecules move from inside the cell to the outside, until the concentration outside the cell is the concentration inside the cell.

Explanation:

• For the first blank: By observing the number of blue dots (representing water molecules) in the "inside the cell" (pink area) and "outside the cell" (yellow area) regions, the pink area has more solute - like particles (implied by the density of blue dots being lower for water), so water concentration inside is lower than outside.
• For the second blank: Osmosis is the movement of water across a semi - permeable membrane. Water molecules can move in both directions across the cell membrane, although the net movement depends on the concentration gradient.
• For the third blank: Since the initial water concentration inside the cell is lower, to reach equilibrium, more water molecules will move from the area of higher water concentration (inside the cell? Wait, no - wait, if the solute concentration is higher inside (so water concentration is lower inside), then water concentration is higher outside. Wait, maybe I mixed up. Wait, the blue dots: if inside the cell (pink) has more blue dots (maybe solute), then water concentration is lower inside. So water moves from outside (higher water concentration) to inside? Wait, no, maybe the blue dots are water molecules. Let's re - examine: If inside the cell (pink) has more blue dots (water molecules) than outside (yellow), then water concentration inside is higher. Wait, maybe I misinterpreted the dots. Let's assume the blue dots are water molecules. Then inside the cell (pink) has more water molecules (more blue dots) than outside (yellow). So water concentration inside is higher. Then water would move from inside (higher) to outside (lower) until equilibrium. So the first blank would be "higher", then more water moves from inside to outside, and finally concentrations are equal. But the initial answer I gave was wrong. Wait, let's start over.

Let's analyze the diagram: The "inside the cell" (pink region) has more blue dots (let's say water molecules) than the "outside the cell" (yellow region). So the concentration of water molecules inside the cell is higher than outside. Then, in osmosis, water moves from an area of higher concentration to lower concentration. So water molecules cross the membrane in both directions (but net movement is from inside to outside). So more water molecules move from inside to outside until the concentrations are equal.

So correcting the first blank: "higher".

So the correct answers are:

1. higher
2. both directions
3. More
4. equal to

The key concepts here are osmosis (movement of water across a semi - permeable membrane down its concentration gradient) and the concept of dynamic equilibrium, where water moves in both directions but net movement is determined by the concentration gradient, and at equilibrium, the water concentrations (and thus the overall solute - water balance) are equal on both sides of the membrane.

Answer:

1. At the start of the video, there is a \textbf{lower} concentration of water molecules inside the cell than outside the cell.
2. The water molecules cross the cell membrane in \textbf{both directions}.
3. \textbf{More} water molecules move from inside the cell to the outside, until the concentration outside the cell is \textbf{equal to} the concentration inside the cell.