When guard cells are full, they bulge. This increases the size of the gap between them and opens the hole in the
leaf.
Guard cell
Water and
oxygen
Carbon
dioxide
Guard cell
Which object is the best model of a guard cell?

Astable electron arrangement for an atom is one that does not easily change. how is this arrangement arrived at? a. valence electrons are transferred or shared to create a full outer shell of electrons. b. valence electrons are discarded into space to create a full outer shell of electrons. c. protons (positive charge) pair with valence electrons (negative charge) to create a strong bond. d. outer shells with valence electrons are transferred or shared.