Alkaloids.
Any of a class of nitrogenous organic compounds of plant origin that have pronounced physiological actions on humans. They include many drugs (morphine, quinine) and poisons (atropine, strychnine).<span />
Head appendages found in anthropods
1) Compound eye - one of the two eye types most anthropods have. They detect edges and are capable of forming images.
2) Ocelli - the other type of anthropod eye. Also known as simple eyes. They can detect lower light levels and have a faster response time.
3) Antennae - They are sensory organs. They sense touch, air motion, heat, sound vibration, olfaction or smell, and gustation or taste.
4) Labrum
5) mandible
6) maxilla
7) labium
D Streak. The student is scratching it on white paper to test the streak.
The correct option is B, SEED.
The seed is a reproductive part of the flowering plants. It has many functions, these include: protection of embryo from injury, production of food for the embryo, protection of embryo from dehydration, etc. The vascular system of the flowering plants makes it possible for the seed to provide the embryo with nourishment; the vascular system is responsible for movement of nutrients and water to all the other part of the plant.