The Eustachian tube originates from the tubotympanic recess, an embryonic structure derived from the first pharyngeal and second endodermal pouches. The proximal portion of the tubotympanic recess forms the tympanic cavity, and its distal portion becomes the Eustachian tube.
I think C) availability of water is your best answer because alot of organisms count on water as a major resource because they need it to survive so a lack or a gain in the amount of water will majorly effect an ecosystem.
These are large molecules which are formed from the union of many monosaccharides units through condensation. Excess glucose in the body is stored in form of glycogen and can be hydrolyzed when glucose levels go down. Glucagon stimulates liver cells to break down glycogen into glucose.
