A gardener is trying to win a competition for the largest pumpkin. Every year, she saves the seeds from the largest pumpkin in her garden. The next year, she plants only those seeds in a large plot. She finds that her pumpkins are becoming larger over the years. Is this an example of natural selection?

No, this is artificial selection.This is because, the selective pressure was not a natural factor, but the farmer  who purposefully selected the best seed based on sizes. Therefore, he did not allow the natural phenomenon to it its cause, but rather chose the most fitted/ viable/largest seeds to germinate.

Explanation:

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.