Embryological evidence
Explanation:
Deuterostomes include echinoderms, hemichordates, and chordates. Despite their diverse body structures, they all feature a mouth that forms secondarily during embryonic development, thought to be a derived evolutionary trait connecting a common ancestor to all its descendants (a synapomorphy). This mouth originates from the ectoderm layer through invagination opposite the blastopore in the gastrula.
Response:
It would need a lower amount of bicarbonate to neutralize the acid.
Explanation:
Sodium bicarbonate (NaHCO3) is a partially soluble sodium salt that breaks down in water to create a weakly basic buffer solution. It separates in water releasing bicarbonate ions (HCO−), sodium ions (Na+), and H+.
2 NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g)
Buffer solutions are maintained in equilibrium. In a solution with a strong acid, the conjugate base reacts, while other carbonate ions release to form carbonic acid, driving the solution back toward balance.
HA ⇄ H+ + A-
Due to its buffering capability, which is how effectively it stabilizes the equilibrium, less bicarbonate will be required later on to neutralize the acid.