Answer:
cellular membranes
Explanation:
Cellular membranes are selectively permeable because they allow only certain molecules to cross into and out of the cell. The phospholipid bilayer is a selectively permeable membrane that surrounds all biological cells. The movement of molecules across the cell membrane bilayer can occur by passive transport (does not require energy) or active transport (requires energy). For example, water molecules pass passively through the cell membrane (passive transport), while other molecules pass through transmembrane proteins against a concentration gradient (active transport).
<span>After one round of replication, you get two brands namely parental DNA, Daughter DNA.The parental DNA is would remain intact.The daughter DNA would be entirely new.After one round of replication in the semi conservative model, all the double standard DNA is composed of one heavier parental and one daughter parental strand.</span>
It’s substrate is the answer to your question