Questions tagged [molecular-genetics]

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

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What do the haploinsufficiency scores in the clinVar database represent?

I understand that haploinsufficiency occurs when one of the two copies of a gene is mutated to the point of being unusable, and the single copy remaining is unable to cope with the cell's demands for ...
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Is bi-allelic gene expression random?

Supposing we have the genotypes “Aa”, “AA”, and “aa”... which are not mono-allelic (not imprinted and not X-inactivated). Does the dominance of the “A” allele over “a” allele affect which gene is ...
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Double stranded RNA Single stranded DNA

I have seen in textbooks referring to ds RNA and ssDNA. How a RNA can be double stranded and likewise how a DNA can single stranded and if they do exist why are there names not interchanged?
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How to identify whether something is in linkage disequilibrium?

If the following loci indicated the presence of an SNP in flu strains, is Locus 2 and Locus 3, which are located 10 bp apart in linkage disequilibrium? "When alleles and molecular markers are ...
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Why don't restriction endonucleases digest transformed plasmids?

In the textbook that I'm using, it explains that bacteria does not digest its own chromosomal DNA because the sites that would be cut by its own endonuclease are methylated. Is there a similar ...
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Which enzyme is Nick Lane referring to?

In Life Ascending the author, Nick Lane, refers to an enzyme in his introduction: '' It concerns an enzyme (a protein that catalyses a chemical reaction) that is so central to life that it is found ...
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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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183 views

If post transcriptional modification happens , how can a gene code for amino acids in a particular order? [duplicate]

Post transcription, introns are removed and exons are rearranged randomly. If that's the case (which it is according to the book EDEXCEL SNAB A2 topic 6) then shouldn't the protein produced be ...
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284 views

Hybrid vs introgression zone in natural populations

In the book An Introduction to Molecular Ecology, the authors say that Introgression is the diffusion of alleles from one population or species into another as a result of interbreeding or ...
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Cloning a coding gene into a non-expression vector

Does it make any sense to clone a CODING gene into a NON-expression vector? doing this will only give us multiple copies of the gene, while we could run PCR instead (Let's say we know the gene ...
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How did the genetic code evolve?

The genetic code is redundant, there are 20 amino acids for 64 possible nucleotide combinations (triplet codons). Therefore some amino acid are coded by several different codons. While leucine is ...
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Are redundant codons used in translation?

I am learning about redundancy in genetics and I came across this statement in my textbook: more than one codon for an amino acid means that some codons are redundant - the process of protein ...
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Why did scientists think humans had 100,000 genes (before the Human Genome Project)?

One of the major results of the Human Genome Project (HGP) was that humans have far fewer separate genes than previously thought. From a 2004 article about the HGP: Francis S. Collins, director of ...
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Name of dsRNA (or dsDNA) where all strands are identical

What is the name of dsRNA (or DNA) where all component strands are identical (i.e. where the complex consists of multiple copies of the same ssRNA)? Example: 2 identical ssRNAs forming a dsRNA ...
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What is the difference between “cistron” and “gene”?

I'm asking after reading the cognate wikipedia.en article on "cistron". I am still not sure about the difference between the two terms. To me it seems valid to picture a "cistron" as the genome wide ...
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Why does the HLA show a high degree of polymorphism?

I know how the HLA undergoes high degree of polymorphism (random genetic rearrangements), but I have not understood why it undergoes rearrangements. What is the advantage offered when HLA shows a high ...
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Why does replication require primers while transcription does not?

In transcription, there is no need for any primer. I guess the basic mechanism of DNA polymerase & RNA polymerase is the same. So why does replication have the need for a primer?
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How exactly does heterozygous sickle trait help patients survive malaria

Heterozygous sickle cell anaemia trait is known to increase the survival rate of carriers to malaria attacks. How does a recessive gene not expressed in the phenotype allow for such an advantage? Is ...
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Are there E-sites on eukaryotic ribosomes?

One of my professors mentioned something about the e-site (the exit site for the t-RNA) on a eukaryotic ribosome. There was a student in the class who objected, saying that there is no e-site on ...
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Is the promoter region of a gene transcribed?

If the RNA polymerase attaches to the promoter region of the gene, would it form the initial mRNA portion soon after attachment by reading the promoter region? Or should it slide across the DNA then ...
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Does the deletion of Chromosome 20 cause immunity against prion disease?

I was reading recently about prion disease and it caught my attention that a normal prion protein is coded n chromosome 20, therefore, in order for an infectious prion protein to attack, there must be ...
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How to find idea for essay [closed]

I'm studying microbiology in Iran The university that I'm studying in doesn't provide that much help in research areas and we don't get to research or write essays that much ,while I'm trying to write ...
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Is there any example of genetic mechanism of delayed onset toxic effects?

We know that exposure to many toxic chemicals during embryonic development may show toxic effects later in life. It is called Developmental Origins of Health and Disease (DOHAD). Most of the ...
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Do nucleosomes ever completely unwrap during transcription?

In eukaryotic transcription will the nucleosomes ever completely unwind the DNA and the histone complex disassemble? If an operon is more 160 base pairs it seems it must.
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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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What does “novel, predicted deleterious, within autozygome” mean in genetics?

I am a medical student and just got involved with a genetic lab and research. I read a lot phrases like: "Although no mutations have been reported in this gene, we think this variant is interesting ...
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Is it theoretically possible to safely eliminate most viruses in the atmosphere, hence preemptively cure all the viral diseases? [closed]

Could we create a genetically modified virus or bacteria (with inability to mutate into something dangerous for animals) that would quickly spread all over the planet and selectively kill most of the ...
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Thousands of Reporters Integrated in Parallel (TRIP) barcodes

Has anyone worked with constructing barcodes for TRIP? How does constructing of barcodes work in general? I don't seem to be able to grasp the basics of constructing these barcodes.
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How does transcription end?

In rho-dependent termination in prokaryotes, how does RNA polymerase “know” that it has reached the end of a gene and that it has to stop so that the rho-factor can bind mRNA’s rut site? Is there a ...
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Young family members to learn genetics - Amino Labs? [closed]

I'm an engineer but want to learn about biology with a niece and nephew who are early teens. I saw Amino Labs (https://amino.bio/) and thought because I work a lot with my hands, doing hands on ...
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169 views

What are the advantages of using interphase cells rather than metaphase cells for gene mapping purposes using FISH?

I have been told that interphase cells are better for gene mapping purposes than metaphase cells but don't know why.
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How do PrP mutations lead to prion disease?

My understanding is: The PrP gene in human cells is expressed as both PrP-c (normal protein) and PrP-sc (prion disease protein). This happens post transcriptionally, that is, the normal and the ...
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What is the role of CRISPR-dCas9 in gRNA-dCas9 transcription regulator complexes?

In this paper, I read that mutant versions of Cas proteins such as a deactivated Cas9 (dCas9) are used alongside a guide-RNA (gRNA) to form variants of CRISPR tool that can function as transcription ...
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About The Selfish Gene Book - How Replicators Molecules forms duplicates?

I was reading The Selfish Gene. In the 2nd chapter - "Replicators" I read: Think of the replicator as a mold or template. Imagine it as a large molecule consisting of a complex chain of various ...
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How does DNA codon (5`-3`) convert to mRNA?

There is a problem I stumbled upon when doing a lesson on molecular genetics (Grade 12 level). The lesson contains many tables in this format: I don't understand how it got to the mRNA codon ...
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464 views

Can a viable embryo develop from the fusion of two egg cells?

For a zygote to form, two haploid gametes undergo meiosis and fuse during fertilisation. Since two egg cells (or even two sperm cells) are both haploid, is it theoretically possible for them to make ...
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True examples of common variation due to Mendelian Inheritance

Classic examples of mendelian inheritance are genetic diseases such as sickle-cell anemia, Tay-Sachs, cystic fibrosis, and xeroderma pigmentosa. For some of these diseases, it is believed that they ...
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What dictates which protein to synthesize at a given time?

I understand how DNA is replicated and how it directs the synthesis of proteins from amino acids through RNA polymerase, RNA and ribosomes. Now I want to understand how it works in the big picture. ...
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What is the most reliable tumour suppressing gene for NSCLC?

I was looking at some tumour suppressing genes that can be helpful in diagnosing lung cancer (particularly NSCLC - Non-small-cell lung carcinoma) at an early stage. I came across a few such as p53, ...
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how can I get stronger staining for my lymph node sections

I am using the same protocol and same antibodies that the literature says but still I cannot get good staining for my lymph node sections, I tried to change the fixation method and I am using now ...
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Isolation of Intact Granules from Mast Cells

How to isolate intact granules from mast cells without using sucrose and percoll?
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Choosing PCR conditions

How does one choose PCR conditions? Does it depend on the taxon, on the DNA concentration, on the primers or anything else?
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Do all retroviruses evolve into dna viruses? [closed]

Since even nonprocreative sex transfers genetic material it seems redundant for viruses to destroy the host. Retroviruses are sufficiently simple to fit into DNA. So why not just become DNA viruses?
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Is it Theoretically Possible to Create a Male clone from the donor Cell of a Female?

I understand that Dolly the Sheep was created without the presence of a sperm cell. Instead, nucleus DNA from somatic cells of adult sheep were used. Since Dolly was female, i am assuming that the ...
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Are the DNA codon mappings arbitrary?

I am a Biology novice so I apologize in advance if I state anything incorrectly.... My question is, are the DNA codon mappings arbitrary? I understand that the DNA code is made up of codons which ...
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Is there a biological explanation for a 0.5 difference in allele size with PCR product?

CONTEXT I am currently working on a set of diversity, this diversity in interspecific (within the same genus). I am using SSR markers, the primers were designed on one species and are working really ...
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Control for Bisulfite sequencing

I am wondering how can I control my converted DNA! I converted my DNA with bisulfite then I amplified the converted DNA with specific primers of BSP and purified my product and finally sequenced the ...
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Expected bands in polyacrylamide gel

I have something in my notes that doesn't seem right. If I use restriction enzymes on a PCR product how many bands should I see provided I know the restriction enzimes will cut the DNA? If I use two ...
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1answer
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Antibiotic resistance

I have a biological puzzle that's been perplexing me for years. Can you review my logic and tell me where I'm wrong or if I'm on to something. As I understand it, most, if not all genetic ...
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What are the types of interactions in biological network (protein networks)?

In the KGML files, the types of relations between genes or proteins are precisely activation, inhibition, expression, repression, indirect effect, state change, binding/association, dissociation, ...