Genetics Exam 2 retake

Taking into account your knowledge of wobble rules, select all anticodons that can pair with the codon 5' - UAC - 3 (check all that apply)

5' -IUA-3' 5'-GUA- 3'

Ozaki fragments do which of the following?

Assist in the synthesis of DNA from the lagging strand.

Which DNA repair mechanism uses DNA N-glycosylases?

Base excision repair

Which of the following is an example of a processive enzyme?

DNA polymerase III

Which region of DNA contains the coding information for a protein in a eukaryote?

Exons

T/F A change in the chromosome number is called a point mutation

False

T/F The anticodon on the mRNA recognizes the codon on the tRNA.

False

What site on the ribosome is primarily responsible for holding the growing polypeptide?

P

Consider the two key roles that have been indentified for SRP RNA. You have isolated a mutant SRP RNA. This RNA os able to perform its role as a scaffold for SRP proteins, but has lost its other function. How will this affect translation of SRP-containing proteins?

Partially translated proteins will be stuck in the cytosol.

Where does the process of transcription initiate?

Promoter

In a 2008 experiment, researchers fed bee larvae a diet that shoulf produce worker bees, but also injected the larvae with a DNA methyltransferase inhibitor. Most of the larvae became what type of bee?

Queen bees

a-helicases and B-sheets are examples of what level of protein structure?

Secondary structure

What general transcription factor is most often affected by regulatory transcription factors?

TFIID

What is the difference between the allosteric and torpedo modles of eukaryotic transcriptional termination?

The allosteric model is that RNA pol II becomes destabilized after transcription of the poly A signal . sequence while the torpedo model is that the polymerase is physically removed from the DNA

Gene methylation can be detected through the use of restriction endonucleases. Usually these are used in pairs where one enzyme will digest only unmethylated DNA in its recognition sequence while the other is insensitive to methylation. Which of the following statements is correct?

The enzyme that is insensitive to methylation serves as a control to make sure the inability of the other enzyme to digest DNA is not due to a mutation.

The primary structure of a protein is directly associated with _______________.

The linear sequence of the amino acids

Which of the following removes supercoiling ahead of the replication fork?

Topoisomerase

T/F Breakpoints in chromosomes can lead to mutant phenotypes when they occur in the middle of a gene.

True

T/F Housekeeping henes are unmethylated and active in most cells.

True

T/F Steroid hormones are an example of an effector which regulates regulatory transcription factor activity

True

T/F: The genetic code is nearly universal in nuclear DNA from bacteria to mammals?

True

translesion-replicating polymerases are ______________.

Used to replicate damaged DNA

Many scientists and drug companies have worked hard to produce drugs to stop various stages of the HIV life cycle. Some drugs have been tested that inhibit the function of Vpu. What stage of the HIV life cycle would such a drug inhibit?

Virus budding

What gene is most responsible for X-inactivation?

Xist

What genes seem to be controlled by the Xic?

Xist and Tslx

You are performing a biochemical purification of enzymes involved in DNA replication. You have purified the replisome. You wish to purify the primosome. You perform further separation techniques on your purified replisome. How will you test to determine that you have purifed the primosome?

You should confirm that you sample has helicase and primase activity. This is the only test that is needed.

A modification that occurs to a nuclear gene that alters gene expression, but not permanently, is called __________ inheritance.

epigenetic

In phage () the relative affinities of the lambda repressor and the cro protein to the three binding sites in the O2 region are ______________.

inversely proportional

Which RNA encodes the sequence of amino acids for a functional protein?

mRNA

The virus that causes chickenpox can also cause ________ decades later when it switches from the latent state and starts making new viral particles.

shingles

What effect would disabling exportin 5 have on RNA interference?

siRNAs could still carry out RNA interference, but miRNAs would not be made.

The holoenzyme is formed when the core enzyme associates with ___________.

the σ subunit.

You have discovered a strain of E. coli that has a higher mutation rate than the normal parental strain from which the mutated strain was created. Upon further investigation, you find a mutation in the DNA polymerase III gene. What subunit of the holoenzyme does this mutation probably NOT affect?

β