0
What names are given to the breaking and rejoining of the chromatids of homologous chromosomes at points of intersection?
Wiki User
∙ 8y ago
centromere
Shivansh Sharma
Add your answer:
Earn +20 pts
What are the sequences involved with protein synthesis from production of mRNA to final translation of the DNA code?
Protein synthesis starts with the DNA which contains the code (blueprint) of the protein. This is first copied to an RNA molecule. In Prokaryotes (bacteria) this is mRNA (messenger). In Eukaryotes (other cells) the RNA copied from the DNA code is first cut and spliced. Small sections of RNA called introns are moved by looping them together then rejoining them. They then become mRNA. The mRNA in both Prokayrotes and Eukaryotes is then passed to the rRNA (ribosomal) where tRNA (transfer) carries single amino acids to the ribosomes where protein is produced.
Why RNA splicing important?
Because DNA cannot fit through the pores of the nuclear membrane, it is too big, the mRNA copies off the specific parts needed and sends the information to where the body needs them. Without mRNA, you could not function properly.
What are the reactions by which muscle fibers produce ATP?
Muscle cells make energy to because when they contract the mitochondria produces or uses (i don't really know which one... by the way im in grade 8) the ATP energy. and that is how muscles use energy. oh yeah one more thing muscles have more mitochondria than any other cells. (ex... skin, nerve stc...)- Teeya
How many types of DNA polymerase are there?
There are 5 known Prokaryotic DNA polymerases:Pol I: implicated in DNA repair; has 5'->3' polymerase activity, and both 3'->5' exonuclease activity (proofreading) and 5'->3' exonuclease activity (RNA primer removal).Pol II: involved in repairing damaged DNA; has 3'->5' exonuclease activity.Pol III: the main polymerase in bacteria (responsible for elongation); has 3'->5' exonuclease activity (proofreading).Pol IV: a Y-family DNA polymerase.Pol V: a Y-family DNA polymerase; participates in bypassing DNA damage.There are at least 15 Eukaryotic DNA polymerase:POLA1, POLA2: Pol α (also called RNA primase): forms a complex with a small catalytic (PriS) and a large noncatalytic (PriL) subunit, with the Pri subunits acting as a primase (synthesizing an RNA primer), and then with DNA Pol α elongating that primer with DNA nucleotides. After around 20 nucleotides elongation is taken over by Pol ε (on the leading strand) and δ (on the lagging strand).POLB: Pol β: Implicated in repairing DNA, in base excision repair and gap-filling synthesis.POLG, POLG2: Pol γ: Replicates and repairs mitochondrial DNA and has proofreading 3'->5' exonuclease activity.POLD1, POLD2, POLD3, POLD4: Pol δ: Highly processive and has proofreading 3'->5' exonuclease activity. Thought to be the main polymerase involved in lagging strand synthesis, though there is still debate about its role.POLE, POLE2, POLE3: Pol ε: Also highly processive and has proofreading 3'->5' exonuclease activity. Highly related to pol δ, and thought to be the main polymerase involved in leading strand synthesis, though there is again still debate about its role.POLH, POLI, POLK, : η, ι, κ, and Rev1 are Y-family DNA polymerases and Pol ζ is a B-family DNA polymerase. These polymerases are involved in the bypass of DNA damage.There are also other eukaryotic polymerases known, which are not as well characterized: POLQ: 'θPOLL: λ?: φ?: σPOLM: μDNA polymerase familiesBased on sequence homology, DNA polymerases can be further subdivided into seven different families: A, B, C, D, X, Y, and RT. Family_A">Family APolymerases contain both replicative and repair polymerases. Replicative members from this family include the extensively-studied T7 DNA polymerase, as well as the eukaryotic mitochondrial DNA Polymerase γ. Among the repair polymerases are Escherichia coli DNA pol I, Thermus aquaticus pol I, and Bacillus stearothermophilus pol I. These repair polymerases are involved in excision repair and processing of Okazaki fragments generated during lagging strand synthesis. Family BPolymerases mostly contain replicative polymerases and include the major eukaryotic DNA polymerases α, δ, ε, (see Greek letters) and also DNA polymerase ζ. Family B also includes DNA polymerases encoded by some bacteria and bacteriophages, of which the best-characterized are from T4, Phi29, and RB69 bacteriophages. These enzymes are involved in both leading and lagging strand synthesis during replication. A hallmark of the B family of polymerases is their highly faithful DNA synthesis during replication. While many have an intrinsic 3'-5' proofreading exonuclease activity, eukaryotic DNA polymerases α and ζ are two examples of B family polymerases lacking this proofreading activity.Family_C">Family CPolymerases are the primary bacterial chromosomal replicative enzymes. DNA Polymerase III alpha subunit from E. coli is the catalytic subunit [1] and possesses no known nuclease activity. A separate subunit, the epsilon subunit, possesses the 3'-5' exonuclease activity used for editing during chromosomal replication. Recent research has classified Family C polymerases as a subcategory of Family X[citation needed]. Family_D">Family DPolymerases are still not very well characterized. All known examples are found in the Euryarchaeota subdomain of Archaea and are thought to be replicative polymerases. Family_X">Family XContains the well-known eukaryotic polymerase pol β, as well as other eukaryotic polymerases such as pol σ, pol λ, pol μ, and terminal deoxynucleotidyl transferase (TdT). Pol β is required for short-patch base excision repair, a DNA repair pathway that is essential for repairing abasic sites. Pol λ and Pol μ are involved in non-homologous end-joining, a mechanism for rejoining DNA double-strand breaks. TdT is expressed only in lymphoid tissue, and adds "n nucleotides" to double-strand breaks formed during V(D)J recombination to promote immunological diversity. The yeast Saccharomyces cerevisiae has only one Pol X polymerase, Pol IV, which is involved in non-homologous end-joining. Family_Y">Family YY Polymerases differ from others in having a low fidelity on undamaged templates and in their ability to replicate through damaged DNA. Members of this family are hence called translesion synthesis (TLS) polymerases. Depending on the lesion, TLS polymerases can bypass the damage in an error-free or error-prone fashion, the latter resulting in elevated mutagenesis. Xeroderma pigmentosum variant (XPV) patients for instance have mutations in the gene encoding Pol η (eta), which is error-free for UV-lesions. In XPV patients, alternative error-prone polymerases, e.g., Pol ζ (zeta) (polymerase ζ is a B Family polymerase a complex of the catalytic subunit REV3L with Rev7, which associates with Rev1[2]), are thought to be involved in mistakes that result in the cancer predisposition of these patients. Other members in humans are Pol ι (iota), Pol κ (kappa), and Rev1 (terminal deoxycytidyl transferase). In E. coli, two TLS polymerases, Pol IV (DINB) and Pol V (UmuD'2C), are known. Family RTThe reverse transcriptase family contains examples from both retroviruses and eukaryotic polymerases. The eukaryotic polymerases are usually restricted to telomerases. These polymerases use an RNA template to synthesize the DNA strand.Variety across Species:DNA polymerases have highly-conserved structure, which means that their overall catalytic subunits vary, on a whole, very little from species to species. Conserved structures usually indicate important, irreplaceable functions of the cell, the maintenance of which provides evolutionary advantages. Some viruses also encode special DNA polymerases, such as Hepatitis B virus DNA polymerase. These may selectively replicate viral DNA through a variety of mechanisms. Retroviruses encode an unusual DNA polymerase called reverse transcriptase, which is an RNA-dependent DNA polymerase (RdDp). It polymerizes DNA from a template of RNA.
What happens during rna splicing m?
Gene splicing means cutting of gene in fragments and rejoining them according to need There are two phenomenon by which gene splicing occur one is natural i.e. post transcriptional modification and other is artifically or by chemical agent used generally in recombinant technologyPOST TRANSCRIPTIONAL MODIFICATION: Gene splicing is a post-transcriptional modification in which a single gene can code for multiple proteins. Gene Splicing is done in eukaryotes, prior to mRNA translation, by the differential inclusion or exclusion of regions of pre-mRNA. Gene splicing is an important source of protein diversity. During a typical gene splicing event, the pre-mRNA transcribed from one gene can lead to different mature mRNA molecules that generate multiple functional proteins. Thus, gene splicing enables a single gene to increase its coding capacity, allowing the synthesis of protein isoforms that are structurally and functionally distinct. Gene splicing is observed in high proportion of genes. In human cells, about 40-60% of the genes are known to exhibit alternative splicing.Gene Splicing MechanismThere are several types of common gene splicing events. These are the events that can simultaneously occur in the genes after the mRNA is formed from the transcription step of the central dogma of molecular biology.Exon Skipping: This is the most common known gene splicing mechanism in which exon(s) are included or excluded from the final gene transcript leading to extended or shortened mRNA variants. The exons are the coding regions of a gene and are responsible for producing proteins that are utilized in various cell types for a number of functions.Intron Retention: An event in which an intron is retained in the final transcript. In humans 2-5 % of the genes have been reported to retain introns. The gene splicing mechanism retains the non-coding (junk) portions of the gene and leads to a demornity in the protein structure and functionality.Alternative 3' splice site and 5' splice site: Alternative gene splicing includes joining of different 5' and 3' splice site. In this kind of gene splicing, two or more alternative 5' splice site compete for joining to two or more alternate 3' splice site.A gene-sized fragment of DNA is isolated from another organism. The bases of the fragment are spliced (joined) to the bases of the molecule by using a chemical called ligase.
What is genetic combination?
in meiosis, prophase 1( the longest stage ) there is a particular stage called PACHYTENE where there is crossing of the chromatids ( the arms of the chromosome) belonging to one paternal and one maternal. there is subsequent breakage and rejoining of the chromatids which results in variation called as genetic recombination.
Is Jerry Dammers rejoining The Specials?
No he isn't, sorry
Can you get sample letter of rejoining to old company?
yes
How can you make an application for rejoining of a discontinued job?
Apply with confidence with clear intent of rejoining. mention all reasons of leaving and everything must be based on truth. ADNAN NAZIR from Pakistan
What is a word that means coming back together again?
rejoining, remerging, remixing, remelding
What is the rejoining of East and West Germany in 1989?
The reunification of Germany in 1989 was called die Wiedervereinigung.
Why was the Americans war necessary?
No war is necessary. But, this was a war over rejoining the Union. So maybe it was.
Why was the American Civil War necessary?
No war is necessary. But, this was a war over rejoining the Union. So maybe it was.
Was the American Civil War necessary?
No war is necessary. But, this was a war over rejoining the Union. So maybe it was.
What does reunification mean?
the process of reuniting or rejoining into one unit
What was Apollo's mission?
The Apollo 9 mission was to test the separation and rejoining of the lunar module in earth orbit.
What is recombination?
Genetic recombination is the process by which a strand of genetic material (usually DNA; but can also be RNA) is broken and then joined to a different DNA molecule. In eukaryotes recombination commonly occurs during meiosis as chromosomal crossover between paired chromosomes. This process leads to offspring having different combinations of genes from their parents and can produce new chimeric alleles.Genetic recombination is the process by which two DNA molecules exchange genetic information, resulting in the production of a new combination of alleles. In eukaryotes, genetic recombination during meiosis can lead to a novel set of genetic information that can be passed on to progeny. Most recombination is naturally occurring. During meiosis in eukaryotes, genetic recombination involves the pairing of homologous chromosomes. This may be followed by information exchange between the chromosomes. The information exchange may occur without physical exchange (a section of genetic material is copied from one chromosome to another, without the donating chromosome being changed)(see SDSA pathway in Figure); or by the breaking and rejoining of DNAstrands, which forms new molecules of DNA (see DHJ pathway in Figure). Recombination may also occur during mitosis in eukaryotes where it ordinarily involves the two sister chromosomes formed after chromosomal replication. In this case, new combinations of alleles are not produced since the sister chromosomes are usually identical. In meiosis and mitosis, recombination occurs between similar molecules (homologs) of DNA. In meiosis, non-sister homologous chromosomes pair with each other so that recombination characteristically occurs between non-sister homologues. In both meiotic and mitotic cells, recombination between homologous chromosomes is a common mechanism used in DNA repair.Genetic recombination and recombinational DNA repair also occurs in bacteria and archaea.Recombination can be artificially induced in laboratory (in vitro) settings, producing recombinant DNA for purposes including vaccinedevelopment.V(D)J recombination in organisms with an adaptive immune system is a type of site-specific genetic recombination that helps immune cells rapidly diversify to recognize and adapt to new pathogens.
