Question

when particles continue to move randomly across a membrane but there is no overall change in their concentration on either side, what condition has been reached? osmosis dynamic equilibrium active transport diffusion the plasma membrane is made of phospholipid molecules arranged in two layers. which part of each phospholipid faces the watery environment inside and outside the cell, and which part is directed toward the center of the membrane? both polar heads and nonpolar tails face outward polar heads face outward; nonpolar tails face inward nonpolar tails face outward; polar heads face inward both polar heads and nonpolar tails face inward

Explanation:

1. For the first question, dynamic equilibrium is when particles continue to move randomly across a membrane but there is no net change in concentration on either side. Osmosis is the diffusion of water across a semi - permeable membrane, active transport requires energy to move particles against a concentration gradient, and diffusion is the movement of particles from high to low concentration without reaching a state of no net change necessarily.
2. For the second question, phospholipids in the plasma membrane have polar heads that are hydrophilic and face the watery environment inside and outside the cell, and non - polar tails that are hydrophobic and face inward towards the center of the membrane.

Answer:

1. B. Dynamic equilibrium
2. B. Polar heads face outward; nonpolar tails face inward