Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

[Q]: Question: What type of plate is an island arc found on? Answer: oceanic
[A]: An island arc is a line of volcanoes on an oceanic plate. A continental arc is a line of volcanoes on a continental plate.

[Q]: Question: While similar to insects, what eight-legged invertebrates lack antennae or wings? Answer: arachnids
[A]: Arachnids do not have antennae or wings.

[Q]: Question: What gland is located at the base of the brain and secretes the hormone melatonin? Answer: pineal
[A]:
The pineal gland is a tiny gland located at the base of the brain. It secretes the hormone melatonin. This hormone controls sleep-wake cycles and several other processes.