Question

In which cell - organelle the products of excretion and secretions are temporarily stored?

Answer 1

The answer is Vacuoles
Hope this helps you

Answer 2

The answer of the your question is "vacuole" 
Vacuoles are the organelles which are found both in plant as well as in  the animal cell. But they are present as much larger vacuoles in the plant cell when compared to animal cell .These are actually act as the storage bubbles  which ma store the food or nutrient necessary for cell survival .
It also stores the waste material like excretion product in  order for the protection of cell from being contaminated.