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According to information given in the question, in early embryonic stages, DNA replication occurs every
Introduction:
DNA replication process occurs in all living organisms. In this process, DNA strands of double stranded DNA get separated; new complementary strands are synthesized, and DNA molecule gets doubled (two identical copies of DNA). DNA replication is a semi discontinuous process, i.e., after separation of DNA strands, one strand gets synthesized continuously and another strand get synthesized in a discontinuous manner.
The origin of replication is a specific sequence of genomes from which DNA replication starts. Eukaryotes have comparatively larger genomes than bacteria. Drosophila genome size is
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GENETIC ANALYSIS: AN INTEG. APP. W/MAS
- The regulation of replication is essential to genomic stability. Normally, the DNA is replicated just once in every eukaryotic cell cycle (in the S phase). Normal cells produce protein A, which increases in concentration in the S phase. In cells that have a mutated copy of the gene encoding protein A, the protein is not functional, and replication takes place continuously throughout the cell cycle, with the result that cells may have 50 times the normal amount of DNA. Protein B is normally present in G1, but disappears from the cell nucleus during the S phase. In cells with a mutated copy of the gene encoding protein A, the levels of protein B fail to drop in the S phase and, instead, remain high throughout the cell cycle. When the gene for protein B is mutated, noreplication takes place. Propose a mechanism for how protein A and protein B might normally regulate replication so that each cell gets the proper amount of DNA. Explain how mutation of these genes produces the effects just…arrow_forwardSuppose that 22% of the nucleotides of a DNA molecule are deoxyadenosine and during replication the relative amounts of available deoxynucleoside triphosphates are 22% dATP, 22% dCTP, 28% dGTP, and 28% dTTP. What deoxynucleoside triphosphate is limiting to the replication? Explain.arrow_forwardAs described in Table, what is the difference between a rapidstop and a slow-stop mutant? What are different roles of the proteins that are defective in rapid-stop and slow-stop mutants?arrow_forward
- Human Genome Replication Rate Assume DNA replication proceeds at a rate of 100 base pairs per second in human cells and origins of replication occur every 300 kbp. Assume also that human DNA polymerases are highly processive and only two molecules of DNA polymerase arc needed per replication fork. How long would it take to replicate the entire diploid human genome? How many molecules of DNA polymerase does each cell need to carry out this task?arrow_forwardReplication involves a period of time during which DNA is particularly susceptible to the introduction of mutations. If nucleotides can be incorporated into DNA at a rate of 20 nucleotides/second and the human genome contains 3 billion nucleotides, how long will replication take? How is this time reduced so that replication can take place in a few hours?arrow_forwardDNA Replication occurs on both prokaryotes and eukaryotes. Although they have a similar genetic flow, there are small differences in between. What are the differences of DNA replication in prokaryotes and eukaryotes? What is/are the major difference/s?arrow_forward
- Eukaryotic Genetic Sequence: 5'-TAC CAT GAT CCC TAT - 3' 1. What would be the newly synthesized DNA strand and explain how the strand will be replicated. Where in the cell would this occur? 2. What would be the synthesized mRNA strand, and how is it transcribed from the original DNA strand, and then converted from a pre-mRNA strand to a mature mRNA? Where in the cell does this occur? 3. What would be the anti-codons for the tRNA. What are the amino acids generated based on the RNA. How are these amino acids translated into protein and where in the cell does this happen?arrow_forwardAs shown, telomerase attaches additional DNA, six nucleotides at a time, to the ends of eukaryotic chromosomes. However, it makes only one DNA strand. Describe how the opposite strand is replicated.arrow_forwardIn eukaryotes, what is meant by the term DNA replication licensing? How does the process occur?arrow_forward
- 1) A bacterial chromosome contains 6.4 million nucleotides of DNA. If synthesis at each replication fork occurs at a rate of 1800 nucleotides per second, how many minutes will it take to completely replicate the chromosome with theta replication? 2) What different mRNA sequences can code for a polypeptide chain with the amino acid sequence Met-Trp-Ile? (Include the stop codon)arrow_forwardIn bacteriophages and bacteria, the DNA is almost always organized into circular (closed loops) chromosomes. Phage l is an exception, maintaining its DNA in a linear chromosome within the viral particle. However, as soon as this DNA is injected into a host cell, it circularizes before replication begins. What advantage exists in replicating circular DNA molecules compared to linear molecules, characteristic of eukaryotic chromosomes?arrow_forwardWhat enzymatic features of DNA polymerase prevent it from replicating one of the DNA strands at the ends of linear chromosomes? Compared with DNA polymerase, how is telomerase different in its ability to synthesize a DNA strand? What does telomerase use as its template for the synthesis of a DNA strand? How does the use of this template result in a telomere sequence that is tandemly repetitive?arrow_forward
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