Circulatory system.....circulates blood (a vital delivery system of oxygen) throughout the whole body when tissues need it the most and with a constant supply.
In this question, there are no options given to choose from. So i would answer this question based on my knowledge. The most likely cause of the observed variation is adaptation and evolution. The birds of that island adapted to the food source and then they evolved as per the requirement of the place and food source.
Answer:
<em>Digestive Processes The processes of digestion include six activities: ingestion, propulsion, mechanical or physical digestion, chemical digestion, absorption, and defecation. The first of these processes, ingestion, refers to the entry of food into the alimentary canal through the mouth.</em>
Explanation: :)
(of an immature or stem cell) capable of giving rise to several different cell types.
