Answer:
organisms are very numerous and diverse
Answer: Serotonin
Explanation:
Serotonin is an hormone, derived from the amino acid, tryptothan. It is involved in vasodilation, sleep regulation, mood changes, capillary permeability, and causes contraction of smooth muscles like that of the stomach to signal hunger.
Light is a form of EM radiation.
EM radiation has no mass (it's just energy packets called photons).
EM radiation can travel through a vacuum. (The speed of light in a vacuum is called c and is around 300,000 m/s).
Hope this helps!
There could be multiple answers to this due to where the hair like fibre is. if it is on a bacteria to aid movement it is called a flagella. if it is attached to a cell, for example in the throat or oviduct, it is called a cilia
