A student is observing different structures of a seed plant during a lab activity. She has identified tiny structures that look like powder.

Angiosperms

Explanation:

Since we know that the student is observing a Seed Plant then we can determine that what she is observing are Angiosperms. These are plants with seeds, whose main characteristic is the reproduction with seeds, as well as having pollen grains on the flowers. These pollen grains are the tiny structures that look like powder which the student has identitfied.