Mutations and DNA Editing
What kind of mutation occurs when a codon is changed into a different amino acid?
Missense Mutations
A repressor molecule ___ gene expression.
Decreases
What percentage of the human genome consists of exons?
1%
During SHM activation-induced cytidine deaminase (AID) converts cytosine into what other base?
Uracil
What is the highly condensed, gene poor, transcriptionally inactive region of DNA that contains many repetitive sequences and is located in the centromeres and telomeres of chromosomes?
Heterochromatin
What kind of mutation is a result of an amino acid being mutated into one of the three stop codons?
Nonsense Mutations
The lac repressor has how many binding sites?
Two
Most genes of an organism are expressed at ___ levels.
Low
Drosha and Dicer are endonucelases that process what type of RNA molecule?
microRNAs
What type of DNA does maintenance methyltransferase act on?
BONUS: What type does de novo methyltransferase act on?
Hemimethylated DNA
BONUS: Unmethylated DNA
If a Adenine is mutated into a Thymine what kind of point mutation is this?
Transversion
The lac-d mutation can inactivate the lac repressor even if it only mutates how many of the four subunits of the repressor?
One
Who discovered transposons / jumping gene in the 1940s?
Barbara McClintock
RNA functions as a regulator by acting as _______ and base-pairing with a single-stranded region.
Antisense
What does HP1 bind to to trigger heterochromatin formation?
Methylated histone H3
A nucleotide deletion or insertion causes what to happen to the codons?
A frame shift / a shift in the codon reading frame
____ of the trp operon means transcription is terminated when higher levels of Trp are present.
Attenuation
DNA microarray technology looks at the expression of which molecules?*
RNA
This type of RNA is complimentary to viruses and originated from viral infections.
siRNA
Xist is a gene that codes for RNA that coats an X chromosome to inactivate it. Xist works in what form?
Cis
What are the three main components of the CRISPER gene editing tool?
Guide RNA, Pam Sequence, and Cas9 nuclease
Name the 5 major classes of eukaryotic transcriptional factors.*
Steroid receptors, Zinc finger motifs, Helix turn helix, Helix loop helix, and Leucine zippers
What enzyme is responsible for site specific recombination that inserts a molecule of DNA into another?
What are the major differences between Drosha and Dicer?
Drosha happens in the nucleus while Dicer happens in the cytosol.
Drosha removes the 5' cap and poly-A tail from RNA while Dicer processes precursor mrRNA into mature miRNA by removing hairpin loop.
What phenomena is responsible chromosomal rearrangement that puts a gene in a region adjacent to heterochromatin which results in the inactivation of that gene?
Position effect variegation (PEV)