The origin of replication is the sequence of DNA where replication is initiated. The origin of replication often has a high content of adenine and thymine nucleotides because they are only bound together by two hydrogen bonds, making the helix easier to open and unwind. There are multiple origins of replication on each chromosome in eukaryotes, while there is only one origin of replication in prokaryotes. The origin of replication binds to initiator proteins that make up the pre-replication complex, which initiates replication.

The only false statement is that DNA replication of the lagging strand is continuous. The leading strand features continuous replication while the lagging stand is initially made up of discontinuous Okazaki fragments, which are sealed later by ligase.

There are four major types of mutations: deletions, duplications, inversions, and translocations. Deletions occurs when a chromosomal fragment is removed and not replaced. Duplications occur when a chromosomal fragment is aberrantly copied. Inversions occur when a chromosomal fragment reattaches to its original chromosome in reverse orientation. Translocations occur when a chromosomal fragment reattaches to a different part of the same chromosome, or a different chromosome altogether.

Helicase is the enzyme responsible for breaking the helix and unwinding the DNA into two separate strands. This allows the polymerase enzyme to attach and start adding base pairs for replication. Primase is responsible for setting and synthesizing RNA primers for polymerase attachment.

Acetylation of histones helps increase genetic expression. Acetylation is the process of adding an acetyl group. Methylation is used by the cell to differentiate between the two DNA strands of a newly synthesized DNA. Essentially, the highly methylated strand is the original or parent strand. This is integral in proofreading the new DNA.

From the lab result, transcription and translation had just occurred in order to create the MHC molecules. In order for transcription and translation to occur, the DNA must not have been condensed (euchromatic).

Euchromatin is a term used to describe an area within the DNA that is much less condensed and highly active transcriptionally. Typically, these areas are seen in highly active cells that are producing many proteins. On the contrary, Heterochromatin are areas that are much more condensed and much less transcriptionally active. On electron micrograph images, euchromatin areas are typically lighter stained vs heterochromatin areas are much more densely stained.

Replication is the process in which the DNA molecule produces two new complementary strands. Transcription produces a messenger RNA, and translation produces a chain of amino acids that become a protein.

DNA polymerase is the primary enzyme involved in DNA replication. It is responsible for adding nucleotides to the growing DNA chain in the 5' to 3' direction. This enzyme also has proofreading functionality, which allows it to remove nucleotides that are mispaired in the 3' to 5' direction and replace them with the correct nucleotide.

The correct answer must complementary base pair with the fragment in the 3’ to 5’ direction because the strands run anti-parallel to each other. Only three of the given options that will run anti-parallel, but only one complements the DNA properly.