What is the best definition of a eukaryotic cell?
has an internal structure consisting of a membrane–bound nucleus and membrane–bound organelles
has an internal structure with the genetic material in the form of a nucleoid
has an internal structure with no membrane–bound organelles

Has an internal structure consisting of a membrane–bound nucleus and membrane–bound organelles

Explanation:

Eukaryotic cells are those that have a nucleus delimited by a nuclear envelope. In this cellular type, the genetic material is not spread through the cytoplasm, as in the prokaryotic cells, but, rather, restricted to the nucleus region. Within the cytoplasm of the eukaryotic cell are immersed several membranous organelles that present the most diverse functions.

from the 10% solution. to the 5% solution

Explanation:

since substances always flow down their concentration gradients unless work is added to the system.