Download PCB 4522 Exam 1 Latest 2024/2025 Academic Year 100% Accurate Fall-Spring (Complete) and more Exams Nursing in PDF only on Docsity!
PCB 4522 Exam 1 Latest 2024/2025 Academic Year 100%
Accurate Fall-Spring (Complete)
The frequency of what types of mutations are used as a molecular clock? synonymous High percentage of what type of mutation indicates positive selection? nonsynonymous mutations 1/2 means how many synonymous and nonsynonymous 2 synonymous; 1 nonsynonymous How long ago did behaviorally modern humans appear? 50,000-100,000 years ago Approx. how many years ago did anatomically modern humans probably first appear? (note: "anatomically modern" defined here is only related to the position of the larynx and windpipe 600,000-700,000 years ago How big was the population of modern humans immediately before the third exodus from Africa ca. 70,000-100,000 years ago? 5,000-10,000 years ago
(t/f) Neanderthals are thought to have the modern configuration of the larynx and windpipe True What are some examples of mutations that suggest that evolution is continuing to change our species? Lactose tolerance and various disease resistance genes We have an expert-written solution to this problem! What transcription factor has undergone comparatively rapid evolution in the interval between chimps and humans, perhaps contributing to the capacity for complex language? FOXP What two actions can all vertebrates, with the exception of adult Homo sapiens, perform simultaneously? Swallow and breathe What's the difference between synonymous and nonsynonymous mutations? Synonymous mutations do not result in a change in the amino acid sequence of the coded protein Which of the following illustrates that the concept of an organism is a matter of definition? A herd of cows A large grove of elm trees in Utah A flock of seagulls A large grove of elm trees in Utah
Which enzyme methylates bacterial oriC? Dam methylase What are the DNA sequence elements of oriC? GATC Dam methylation sites, DNA protein high and low affinity binding sites Under what circumstances can the replication fork be bidirectional? When the origin of replication creates two replication forks that move in the opposite directions What is a replicon? Unit of DNA in which individual acts of replication occur What is the function of Tus protein? It acts as a contrahelicase by unwinding DNA in the opposite direction from the replication helicase, DnaB Which statement is TRUE regarding replication control?
- Chloroplast DNA displays single-copy control.
- Mitochondrial DNA displays single-copy control.
- The Eukaryotic chromosome must activate replication only once per cell cycle.
- The bacterial chromosome can replicate several times before cell division. The Eukaryotic chromosome must activate replication only once per cell cycle.
Why does it take so long for the origin of oriC to be able to initiate a second round of replication? Because SeqA binds to hemimethylated DNA and sequesters it to the membrane Which mechanism does NOT contribute to the control of reinitiating of bacterial replication?
- Inhibition of DnaA binding and its transcription
- Delay in demetylation
- Delay in remethylation
- Physical sequestration of oriC Delay in demethylation What is the function of the ter sites in the genome? Serve as backup to prevent bacterial replication forks from going too far What is the replication fork? Point at which replication is occurring Which chemical reaction occurring at the bacterial origin of replication plays a role in the regulation of initiation? Methylation The Bacterial origin of replication, oriC can only initiate replication when _____? It is fully methylated on both strands at the adenines Which two proteins are unstable in yeast, bind to the ORC, and are only synthesized during the G1 phase of the cell cycle?
The ____ is a complex containing 6 proteins that bind to the A and B1 domains of the yeast origin of replication and is required for replication of the chromosome. ORC Which function is NOT regulated by the bacterial origin of replication? Termination of replication Which of the following is a transcription factor associated with the origin in yeast? ABF What is the role of the Geminin protein in the initiation of eukaryotic DNA replication? Once bound to the Cdt1 protein, it blocks further binding of the helicase, MCM We have an expert-written solution to this problem! What is the average size of replicons found in eukaryotic genomes? 40kb - 200kb How does DNA replication terminate in yeast (fungus), Drosophilia (insect) and Arabidopsis (plant)? The DNA polymerases run into each other from opposing directions, which results in a fusion of the replication eyes. How many replicons can be found in typical eukaryotic genomes?
At which point in the cell cycle is Geminin degraded? Late M phase and early G1 phase During which cell cycle phase is DNA replicated in eukaryotes? S Is mitochondrial DNA replication considered bi-directional or uni-directional and why? Uni-directional: Even though both strands get replicated, each uses a seperate unidirectional origin. We have an expert-written solution to this problem! (t/f) Most of the protein encoding genes in mammalian mitochondrial DNA are located on the same strand that is displaced in the D-loop True bbbeach What are the major roles played by the Light Strand Promoter present in mitochondrial genome? It serves as a promoter for ___ and ___ Initiating the RNA primers for DNA replication; For synthesis of mRNA to express mitochondrial genes What is Light Strand Promoter (LSP)? And what does it do? LSP is an important promoter to initiate Mitochondrial DNA replication; It's used to transcribe the genome and to provide the start nucleotides for the 7 S primers
D-loop of mitochondrial DNA Mitochondrial genes are pretty closely packed. What type of genes are located in between the protein-encoding genes? tRNAs Identify the location designated "4" in the figure of mitochondrial DNA. the light strand promoter (LSP), which is used to transcribe the genome and to provide the start nucleotides for the 7 S primers. What are the two major roles played by the Light Strand Promoter present in the mitochondrial genome? It serves as a promoter for ____________ and _____________. initiating the RNA primers for DNA replication; for synthesis of mRNA to express mitochondrial genes We have an expert-written solution to this problem! Which of the numbered molecules is (are) used to prime DNA synthesis when mitochondrial DNA is severely depleted? molecules 1 and 2 In eukaryotes the chromosomes are linear DNAs. How is the problem of replication handled? The ends of the chromosomes contain telomere repeat sequences that do not contain genes, so failing to replicate the complete 5-ends of the template has little consequence. There are difficulties in replicating linear DNA. What are they?
The primer must be supplied. No place for the DNA polymerase to attach at the end. (No place to sit.) Linear templates: How do T4 and Lambda phage solve the problem of having linear double- stranded DNA templates? They dont. Instead, they both convert from a linear form to a circular form and then use the rolling circle mechanism. PhiX174 replication: Which of the following is NOT a function of Protein A? nuclear localization Which of the following is primed in DNA replication by a single nucleotide (CTP) covalently linked to a protein? Adenovirus Adenovirus replication: What happens to the Terminal Protein after priming? It remains permanently covalently linked to the 5-terminus of each strand. Plasmids are like phages in many respects. Which of the following is FALSE? Both produce infective particles. Plasmid copy number: Why is a mechanism for segregation not important for high-copy plasmids? Once you have over 10 copies per cell (i.e. high copy), chances, based on simple probability, of getting at least one copy of the plasmid in each daughter cell is very high.
Vir____ is a histidine kinase trans-membrane protein, which autophosphorylates when it binds an inducer. VirA Which vir genes recognize right border and nick it, thus generating the primer for DNA strand synthesis? virD1 and D What are the basic features of the miniTi vector plasmids? left and right border sequences, selectable marker, bom site for mobilization into Agrobacterium Vir ____ binds to the single strand of the displaced T-DNA single-strand, and Vir _____binds to overdrive DNA. VirE2 and VirC Which protein is phosphorylated by VirA and then acts as a positive transcription factor? VirG In the Ti plasmid (pTi)-based Binary vector system, where are the vir genes located? on the modified pTi Which vir proteins perform an analogous function as TraY and TraI? VirD1 and VirD
The soil bacterium Agrobacterium tumefaciens infects plants at a wound site. What is the signal that activates the vir locus as a result of the wound? Phenolic compound acetosyringone Which of the following proteins from the pTi are transferred to the plant cell? VirD2 and VirE Whys it important for the Overdrive element to be located next to the Right Border instead of the Left Border? (Read the answers carefully.) This ensures that the right border is cut first. Otherwise the entire T-DNA region would stay in the bacteria instead of being transferred. _____ activates the _______ response regulator by phosphate group transfer onto its receiver domain. VirA and VirG The following genes are located on the Agrobacterium tumefaciens chromosome: chvA, chvB, chvE and pscA. Which of these genes encodes a protein that binds to simple sugars and to the extracellular domain of VirA? ChvE In Agrobacterium, ___ and ___ comprise bacterial a two-component signaling system. VirA and VirG
What entity transferred from Agrobacterium to the plant nucleus causes the production of the crown gall tumor? T-DNA he ____ protein is embedded in the membrane of Agrobacterium and senses the presence of acetosyringone from the wounded plant cell. (In your answer include the full name of the protein: for example ChvX or VirX, instead of the X protein.) VirA Which three proteins perform analogous functions in various models of replication? (functionally analogous, not necessarily structurally analogous) Protein A, virD2, TraI What would happen if the Left Border sequence was deleted from the pTi (Ti plasmid)? The entire pTi would be transferred to the plant cell. The ____ protein binds to the overdrive sequence at the right border of T-DNA to ensure that the nick occurs at there before the left border. (In your answer include the full name of the protein: for example ChvX or VirX, instead of the X protein.) VirC Compatibility groups: Which of the following statements is TRUE? Plasmids in the same compatibility group can not co-exist in the same cell over long time periods, since the same negative regulatory molecules control both plasmids.
ColE1: Which of the following molecules enable, or facilitate, the negative regulation of DNA replication RNA I and ROM protein What is a protein involved in Coli E1 plasmid replication ROM protein When a bacterial cell replicates its genome (DNA), it soon divides. Which statement is FALSE? The Xer resolvase uses a site-specific mechanism of recombination. It must act at the diff site. The ter regions migrate to either end of the dividing cell (away from the forming septum). The ter regions migrate to the middle plane of the dividing cell near the forming septum. If the two newly replicated genomes undergo recombination, the Xer resolvase splits the two genomes apart. The ter regions migrate to either end of the dividing cell (away from the forming septum). What is a transcript that forms a double-stranded duplex with RNA II in order to disrupt priming of DNA synthesis for replication? (know what the picture looks like) RNA I Bacterial DNA replication can be divided into two processes: 1 - DNA synthesis and 2 - formation of the septum in preparation for the physical separation of the two daughter cells. Which of following statements is FALSE? C=40 min and D=20 min
F plasmid: Where is the nic site located? in oriV in the TraI encoding region in the finP gene in oriT - in oriT F plasmid immunity: Which inner membrane protein blocks the transfer of DNA between F positive cells? TraM TraJ TraS TraT - TraS Tra locus: Which protein(s) senses that a stable mating pair has formed and then allows TraI to nick at oriT? TraD TraB TraM TraN and G - TraM Tra locus: Which protein is called the "Copilot protein" because it covalently links to the 5'-end of the transferred DNA and leads the DNA into the recipient cell? TraI FinP TraY TraJ - TraI
Tra locus: Which protein(s) shares many of the activities of PHiX174 Protein A? TraI/Y TraS/T Tra M TraJ - TraI/Y Tra locus: Which protein is the first protein translated on the long polycistronic transcript (RNA) and recognizes oriT? TraD TraY TraI TraA - TraY Tra locus: Which protein directs the TraY/I/M-DNA complex to the T4SS channel? (Note: It was not covered in the lectures, but TraT/Y complex also contains TraM.) TraM TraT TraD TraM - TraD F plasmid immunity: Which protein blocks contact between the Tip protein of the pilus between two F positive cells? TraM TraT TraA TraS - TraT
