The only correct post-transcriptional modification from the answer choices is the addition of a 5' (methyl guanosine) cap. The remaining answer choices are either false, or examples of post-translational modifications.

RNA polymerase transcribes a DNA template in the 3' to 5' direction, creating an RNA molecule 5' to 3'. The DNA sequence given in the question therefore needs to be flipped around and read in the 3' to 5' direction in order to determine the resulting what the RNA sequence will be 5' to 3'. Additionally, the nitrogenous base thymine (T) is replaced by uracil (U) in RNA, so every location where a T would go in the RNA sequence needs to be replaced by a U.

From the passage, chromosome 6 carries the information for the MHC molecules. The chromosomes are stored in the nucleus of the cell. Therefore, transcription occurs in the nucleus. 

The process by which the genetic code of DNA is copied into a strand of messenger RNA is called transcription. Translation uses messenger RNA, transfer RNA, and ribosomal RNA to create a chain of amino acids that become a protein. Replication is the reproduction of two strands of DNA that are used in a new cell.

When finding the mRNA transcript from a template, there are two things to keep in mind:

1. The template strand will be complementary to the transcript, so it will be read in the opposite direction

2. Since the template strand is made from DNA, it will have thymine bases instead of uracil (which is found in RNA in place of thymine).

First, we can reverse the direction of our given DNA sequence.

5'-TACGCATT-3'

3'-TTACGCAT-5'

Then, complete each base pair. Guanine (G) and cytosine (C) always pair, and adenine (A) and thymine (T) always pair. In this case, since we are dealing with RNA, uracil (U) will have an adenine complement.

5'-AAUGCGUA-3'

Okazaki fragments are only produced, and subsequently joined together, in the lagging strand to allow for replication in the opposite direction as replication fork movement. The leading strand, however, allows for continual replication.

All other choices reflect aspects of DNA replication for both the leading and lagging strands.

Point mutations replace a single nucleotide for a different one. This can change a certain codon to code for a different amino acid (missense), the same amino acid (silent), or lead to a stop codon (nonsense). Nonsense mutations are the most severe type of point mutation, as they will cause early termination of the protein.

This is really just a math equation. We need to double the amount of DNA each time it goes through a replication cycle.

Begin: 4

Cycle 1: 8

Cycle 2: 16

Cycle 3: 32

Cycle 4: 64

Cycle 5: 128

Cycle 6: 256

Cycle 7: 512

Cycle 8: 1024

Cycle 9: 2048

Cycle 10: 4096

After ten cycles, we would have 4096 copies from our original 4.

A shortcut calculation would be .

This is why PCR amplification is so effective.

The complementary strand will be going in the opposite direction (3'-5'). As a result, you will need to flip the direction in order for it to be complementary to the original strand. When pairing bases, remember that guanine (G) and cytosine (C) are paired with one another, and adenine (A) and thymine (T) are paired.

5'-ACTTGACT-3' Switch the direction.

3'-TCAGTTCA-5' Find the complement pairs.

5'-AGTCAAGT-3'

Single-strand binding protein (SSB) binds the newly separated DNA strands to ensure that it does not reanneal during replication. This keeps the strands separate so that replication can occur.

All of the other answers describe the functions of other proteins. Primase synthesizes the RNA primers, which helps to recruit DNA polymerase. The structural basis for the replication of the leading and lagging strands ensures that replication follows the same rate on both strands.