Ferns and pine trees can be classified as different organisms from each other based on whether they have

Seeds
A non-vascular system
Flowers
Vascular system

Ferns do not have seeds, flowers, or a vascular system, while pine trees do have seeds, a vascular system, and no flowers. Therefore, ferns and pine trees can be classified as different organisms based on the presence or absence of seeds, flowers, and a vascular system.