The scientific study of the structure and function of genes at the molecular level, particularly chromosomes and DNA.

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Why does pETDuet-1 only have one T7 terminator but two T7 promoters?

Why does pETDuet-1 only have one T7 terminator but two T7 promoters (vector map below)? Is there any advantage of having only one terminator? There are going to be two mRNAs transcribed from this ...
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What is the highest number of genes expressed under one T7 promoter?

What is the highest number of genes expressed under one T7 promoter? Also, what is the longest polycistronic mRNA? I am interested in the context of heterologously expressing biosynthetic gene ...
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22 views

What the gene variation detection result can tell us about a cancer [duplicate]

We do a research on a particular cancer, now we have a result of the gene variation detection . What next steps do we need to do? we don't have a clear picture about this. Can you give us some ...
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64 views

Which strand of a gene specifies a protein? [closed]

A gene is a segment of DNA (I hope double stranded) and each strand when transcribed form a mRNA and after being translated a protein. As from each gene there are two proteins that are being formed. ...
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77 views

Genomic DNA isolation from wheat

Can I use dry seed, wheat for example, in place of young leaves for isolation and purification of genomic DNA for PCR amplification? The goal of my experiment is to validate a novel gene which is ...
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97 views

Is it possible to have multiple stop codons in one exon?

I would be very happy if someone can help me to find the answers for the following related questions. Can one exon have many stop codons? Can protein synthesis happen, if the stop codon is at the ...
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80 views

Can both the overlapping genes (in opposite strands) produce proteins?

I have recognized that both the forward and reverse transcripts from a genomic location code for protein products. Both do occur/express in the tissue of interest. In order to eliminate by chance ...
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What's the difference between shotgun sequencing and clone based sequencing?

In a lecture during my undergraduate degree we were introduced to the race to complete the human genome. Celera were competing with Sanger and collaborators to sequence the human genome. Celera ...
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83 views

Can difference in the expression potential of alleles lead to dominance?

Several hour ago I was in thoughts what allele dominance really means on molecular level. As we know from basic genetics, if the organism had Aa type of some gene ...
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Do other animals have different blood types?

Humans have the ABO and Rhesus blood typing systems. I have two questions about it: Why have we evolved these blood types? Do other animals have different blood types as well?
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mutant and variant differentiation

Can anyone clearly differentiate between a variant and a mutant in genetics. I am confusing these terms a bit, as the evolutionary aspect also comes to my mind.
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How much time do the different mechanisms of gene regulation need to take effect?

I am thinking of the major regulatory mechanisms, like general transcription factors, activators, repressors, and RNA interference. If non-active regulator genes using each of the different ...
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Why mutations in genes involved in general processes like DNA repair increase the risk of developing specific types of cancer?

For example, mutation in MHS2, which encodes a protein involved in the repair of mismatches that occur during DNA replication, dramatically increases the risk of developing colon cancer. (There are ...
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Difference between mutation and DNA damage

What is the strict difference between mutation and DNA damage? As far as I understand it, a mutation is an alteration in the genetic sequence, having "tricked" the repairing machinery and thus ...
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20 views

When should you use a stringent plasmid

I was wondering if anyone had good examples of when you would want to use a stringent plasmid vs a relaxed plasmid in a research setting. Thanks
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108 views

How to read this DNA inversion diagram?

In the following diagram about chromosome inversion, I don't understand: Why do we need to take the reverse complement from step 1 to 2? Isn't inversion just reversing the bases in the region? How ...
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30 views

Do any gaps in DNA during cell division (meiosis in particular) lead to crossover?

I have some gaps in the knowledge abour crossover. I know, that crossover is connected with reparation process. I'd like to know if all gaps in chromosomes lead to crossover (reparation based on 2d ...
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967 views

Viral Mutation Mechanism

I think I have a wrong concept about viral mutation process. First of all what is mutation actually? I mean, I know it's a sudden change in DNA, happening when subjected to mutagenic agents. But can ...
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UV light-induced mutagenesis during gel extraction

this is a very short question I did not find the answer for online, neither on this nor other fora. At the beginning of my cloning protocol, I extracted the band with the sequence of interest directly ...
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50 views

Trouble understanding overlapping genes.

I read the wikipedia passage on overlapping genes. https://en.wikipedia.org/wiki/Overlapping_gene The Tandem overlaps they speak of make sense to me, as I understand that their are different reading ...
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Why are some genomic regions sequenced more than the others?

We have to normalise read count data from RNA-Seq experiments in order to account for the fact that some genomic regions are mapped more than others. i.e. we get the tags per million reads (TPM). In ...
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27 views

Synthesis of an additional DNA in Pachytene and Zygotene [closed]

I've read, that in Pachytene and Zygotene additional DNA material is synthesized, about 0,3, 0,1% respectively. Why is it so?
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28 views

How accurate are proteomic-based biomarkers of cancer? [closed]

Currently protein expression is one of the widely used biomarker types. For example, any $i^{th}$ protein could be a selected biomarker. How can a minute change in single protein concentration ($m/...
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137 views

What is the difference between the mitotic spindle and microtubules?

In mitosis, I understand that the centromeres line up on the spindle. I also know that the centrioles form microtubles between the centromeres during mitosis in the metaphase. But, are microtubles ...
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Are all genes transcribed in differentiated cells?

My textbook tells me that it’s specific transcription factors that allow for a different set of genes to be expressed in different cells (differential gene expression). My book gives the example of ...
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During the process of correcting mutations via gene therapy, is the defective gene removed?

Just recently started learning about gene therapy, many websites explain that the corrected DNA can be added to the genome using a vector and all that. I just don't understand what happens to the ...
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Molecules, Targets and Isoforms

I have a question. Given a molecule A and two isoforms of a gene X, Y, and the knowledge that A targets X. Can I infere from this anything about whether A targets Y? As a motivation think about ...
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105 views

What is two-start or zigzag model of 30 nm chromatin fibre?

I read some webpages describing the two-start model but could not get it. I'll be obliged if someone helped me understand the topic. The websites I have been through are: 1.http://www.nature.com/nrm/...
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How can a mutator gene can cause a mutation when it is shut off? [closed]

defination of "Mutator" - a gene that increases the rate of mutation of one or more other genes. However, in the book "Molecular Biology of the Cell" (bruce alberts) it states that when a mutator is ...
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What separates gene loci?

Introns are sections of noncoding DNA that separate exons within a gene locus. However, between different gene loci, I also would assume there to be noncoding regions of DNA. What are these regions ...
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How was gene therapy able to cure diseases through the transformation of actively dividing cells?

I thought that gene therapy, when performed on target cells that regenerate themselves constantly, can be effective for a limited time only. I.e., the effect gradually wears off after a while, ...
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75 views

How do the major and minor grooves in the DNA helix arise?

I understand that they arise due to the pairing of bases of two opposite stands and are sites through which important proteins needed for replication and transcription of DNA interact. But I don't get ...
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154 views

What is positive and negative supercoiling?

Is the following correct? Positive supercoiling = the coiling of DNA helix (B-DNA) on itself during intesified coiling of the two DNA stands in right handed direction negative supercoiling = the ...
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Mosaic segregation in C. elegans

How can mosaic segregation be used in C. elegans? Can it tell us where a given gene is expressed, or needs to be expressed for worm survival?
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Does DNA polymerase I require a $3^\prime$ end?

DNA polymerase III adds nucleotides in the $5^\prime \rightarrow 3^\prime$ direction because it can only add nucleotides to the $3^\prime$ end of the previous nucleotide. This is why it requires a ...
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Hydrogen bonding and the blocking thereof in nucleic acids during nuclear processes

In transcription, RNA polymerase unwinds the DNA double helix and begins attaching RNA nucleotides to the template strand. In its wake, the DNA double helix closes back—this is only natural, seeing as ...
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45 views

Mitochondrial Genetic code

We know that the genetic code is universal. My query is why the mitochondrial genetic code is different from universal genetic code?
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Why is mRNA used as a biomarker for cancer over tRNA or rRNA?

I cannot find a clear explanation for why mRNA is used as cancer biomarker and not tRNA or rRNA. Is there something peculiar about mRNA which cannot be fulfilled by tRNA or rRNA?
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23 views

What are in common between transcription factors?

In terms of their structures (primary to tertiary) and locations? Why do they have these commonalities? Or are any of these commonalities critical to their functions?
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What type of point mutation and chromosomal mutation cause Albinism in humans?

First of all, I know that OCA1 (Oculocutaneous Albinism Type 1) is autosomal recessive which means that both parents-who are unaffected-have to pass down one copy of a mutated gene in order to ...
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104 views

Why are fifth order Markov Models, the ones most often used for gene prediction?

As far as we know that smallest polypeptide chain length is 60 amino acids - so if we found an Open Reading Frame (ORF) of about 60 codons without the interruption of stop codon we can consider it to ...
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Genetic linkage greater than 50 centimorgans

Classically, the linkage between two loci can be measured in centimorgans (cM), which represents the percent chance that these two loci will recombine an odd number of times (generating a recombinant ...
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Crossing over and exon shuffling?

Campbell Biology 10e, in discussing the functions of introns, writes: The presence of introns in a gene may facilitate the evolution of new and potentially beneficial proteins as a result of a ...
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XNAs as a Genetic material [closed]

I heard there is a new genetic material called XNAs.I wanted to know more about this.Does anyone about XNAs as genetic material?
3
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104 views

What came first? The DNA or the DNA polymerases?

I know this sounds a lot like chicken and egg question and while the latter has an answer, I am intrigued about the former. A modified form of the question would be, in the course of abiogenesis, ...
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How does a test like the Natera Panorama distinguish the child's genome from the mother?

Blood tests on an expectant mother, like the Natera Panorama, are now being used regularly to screen fetuses for chromosome abnormalities. At my wife's recent prenatal visit, she wasn't really even ...
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92 views

Explain allelic complementation at molecular level

I know that Allelic complementation is a phenomenon where two recessive loss-of-function allele generate a functional gene product by compensating each others' defect. But I don't get how do they ...
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50 views

probe amplification in MLPA

I'm reading an article about MLPA (Multiplex ligation-dependent probe amplification) and I got stuck on this sentence: The advantage of splitting the probe into two parts is that only the ...
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345 views

Gene and alleles

This is a multiple choice question: Consider a gene, ABC, which codes for an enzyme involved in the metabolism of sugars. There are two known alleles of this gene, ABC1 and ABC2. Which statement ...