A chemical reaction happens
A plasma membrane is formed of two layers of phospholipids. That is why the membranes are also called phospholipid bilayer. the outer layer points inwards towards the cell and inner layer. the inner layer points towards the outer layer. I've drawn a pic and labelled it.
<em> DNA replication needs to occur because existing cells divide to produce new cells.Each cell needs a full instruction manual to operate properly. So the DNA needs to be copied before cell division so that each new cell receives a full set of instructions!</em>
<h2 /><h2 /><h2>
<em>HOPE</em><em> </em><em>IT</em><em> </em><em>HELPS</em><em> </em><em>YOU</em><em> </em><em>OUT</em><em> </em><em>PLEASE</em><em> </em><em>MARK</em><em> </em><em>IT</em><em> </em><em>AS</em><em> </em><em>BRAINLIEST</em><em> </em><em>AND</em><em> </em><em>FOLLOW</em><em> </em><em>ME</em><em> </em><em>PROMISE</em><em> </em><em>YOU</em><em> </em><em>TO</em><em> </em><em>FOLLOW</em><em> </em><em>BACK</em><em> </em><em>ON</em><em> </em><em>BRAINLY.IN</em></h2>