Which best describes dynamic equilibrium?

a. there is a difference in concentration on either side of the cell membrane.
b. there is an uneven distribution of particles inside and outside the cell.
c. particles are moving into and out of the cell, but their concentrations remain stable.
d. a concentration gradient is forcing water out of the cell and particles into the cell.

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

hi~~

i would say that hybridization occurs frequently in nature, because there are many types of hybrids that have occurred naturally, such as the mule (male donkey + female horse)