Given the consensus sequences for mRNA splicing (see the Dx resource) and the sequences spanning the 5′ and 3′ splice junctions of the first intron of the human β-globin gene where the first nucleotide of the intron is at position 1 and the last nucleotide of the intron is at position 130, Determine the effect on mRNA splicing for the following mutations. mRNA splicing.png Answer choices: Impaired Not impaired Mutation Effect on mRNA splicing Position 123,   A –> C [BLANK-1] Position 128,   U –> C [BLANK-2] Position 130,   G –> A [BLANK-3] Position 132,   C –> A [BLANK-4]

The 5’ end of the γ-globin mRNA is shown below, aligned with its gene and protein sequences. The ribosome initiates translation at the first AUG codon it encounters in the mRNA starting from its 5’ end. Given an A–>T mutation in the wild-type initiation codon, click on the new translation start site.

Select the statement that best describes how the threonyl tRNA synthetase (ThrRS) is able to minimize mis-acylation of threonyl tRNA (tRNAthr) with serine.

Identify a DNA polymerase substrate.DNA pol substrate.png 

The TATA box/TATA-box binding protein complex is shown below. The TATA-box-binding protein is in blue (backbone trace). The TATA box, within the DNA double helix, is in CPK spacefill (A, Cyan; T, yellow). Answer Yes or No to the following questions. TBP_TATAbox_letters.png Answer choices: Yes No Question Answer Is the TATA box palindromic? [BLANK-1] Is the TATA box on the sense strand? [BLANK-2]

Identify the step in semi-discontinuous DNA replication that does not require energy input.

Click on the DNA polymerase substrate whose de novo synthesis is not directly impaired by folic acid deficiency.

Classify the fundamental unit of the nucleic acid starred in the figure below. ATG.png 

Inactivation of the 3’-5’ exonuclease activity of DNA polymerase III disables the proofreading mechanism of this enzyme. The result will be

Both RNA and DNA can form double helices. Propose the most likely chemical component of RNA that influences it to form a right handed A helix as opposed to the right handed B helix, which is the most common form of DNA.