20% Cytosine (molar)
20% Guanine
30% Adenosine
30% Thymine
2.) TRUE:
Whenever DNA replicates itself it undergoes a specific process, which is as follows...DNA helicase first unzips and unwinds the DNA molecule, forming a 'bubble' between the two strands. Then single stranded binding proteins bind to each of the strands, holding the bubble open. Once the bubble is held open, DNA primase can attach to one of the strands on the 3' end and begin building the leading strand. Simultaneously on the opposite strand, RNA primase is building short strands of RNA, also known as Okazaki fragments. After a number of Okazaki fragments are built, a 2nd type of DNA polymerase comes in and removes the RNA primers, replacing them with DNA. Later DNA lygase stitches the DNA fragments together, creating a unified strand of DNA. Once both strands are finished polymerizing, the resulting two DNA molecules have one 'new' strand and one 'old' strand, which is why the process is often referred to as semi-conservative. Also, the reason both strands can't be polymerized continuously is because DNA is ALWAYS polymerized in the 5'--->3' direction.