Here's why:

* Parenchyma tissue is the fundamental tissue of plants, responsible for photosynthesis, storage, and other metabolic functions.

* Chloroplasts are the organelles responsible for photosynthesis, where sunlight is converted into chemical energy.

* Since parenchyma tissue is the primary site of photosynthesis in plants, it contains a large number of chloroplasts.

While other tissues like the mesophyll in leaves also have a high concentration of chloroplasts, parenchyma tissue is a more general term that encompasses this type of cell across the plant body.