Across
2. when a solution has a lesser concentration of particles
4. membranes that let some things through, called selectively ______
7. the diffusion of water
9. the outer boundary of the cell
11. prefix that means "outside"
13. the engulfing of large particles
14. turns color in the presence of starch
15. word that means "cell"
16. a difference in concentration creates a concentration ______
17. when a solution as a greater concentration of particles
18. a type of active transport; sodium-potassium ____
21. type of transport that requires energy
Down
1. movement of molecules from high to low concentration
3. a molecule composed of two hydrogens and one oxygen
5. a solution that has an equal amount of particles
6. prefix that means "inside"
8. organelle that helps remove excess water; ______ vacuole
10. when molecules are evenly spread in an area
12. the maintaining of an internal balance
19. type of transport that does not require energy
20. a protein that helps things across the membrane