Answer:
Populations have variation in traits due to random mutation, crossing over and environmental conditions.
Stereomicroscopes is that they have a much lower magnification limit than other microscopes, such as the compound microscope, for instance. The stereomicroscope can magnify an image 100-150 times, while normal compound microscopes can magnify an image 1000-1500 times. This can be a disadvantage of stereomicroscopes, because not as much detail of the image is seen.
