The end product of the Calvin cycle that is used to make glucose and other sugars is glyceraldehyde 3-phosphate (G3P).

Here's why:

* The Calvin cycle's main function is to fix carbon dioxide from the atmosphere and convert it into organic molecules.

* G3P is a 3-carbon sugar that is produced in the Calvin cycle.

* Two molecules of G3P are needed to make one molecule of glucose.

* G3P can also be used to make other sugars, amino acids, and fatty acids.

So, while the Calvin cycle produces other molecules, G3P is the key intermediate that is directly used to build the sugars that are essential for plant growth and energy storage.