Why have scientists used genetic modification on fruits and vegetables?

To better improve their freshness so basically they can last  longer and still taste decent 

To make them look more appealing and taste better. Also to produce more at a time and to add pesticides into the fruit.

Glucose, also called grape sugar, blood sugar or corn sugar, is among the simplest and one of the primary naturally occurring sugars. produced naturally by plants as the primary photosynthesis product, it is heavily used by living beings as a main energy source and is necessary for cellular respiration. chemically, it is a monosaccharide carbohydrate and serves as a building block for complex sugars like starch.