What would be the sequence of
nucleotides that pair with GCA?

true is the

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added