A) transports oxygen and carbon dioxide for the respiratory system
DNA replication goes in the 5' to 3' direction because DNA polymerase acts on the 3'-OH of the existing strand for adding free nucleotides. DNA replication can take place both the directions chemically. ... But these nucleotide triphosphates hydrolyze spontaneously under aqeuous conditions.
Answer: "homeostasis" .
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Calcium oxide based on the above explanation is an ionic compound.
