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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Is one DNA molecule same as one chromosome [duplicate]

Is one DNA molecule = one chromosome or is one DNA molecule = all the chromosomes, ie, all the genetic material in our cells? I have googled it but I am not getting clear answers ?
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How to calculate the quantification of qPCR to the equivalent of the number of nuclei in fungi?

I have a question about the quantification through qPCR. The my question is: if I made the qPCR of a fungal functional gene, how is possible to obtain from the quantification number (in nanogram) the ...
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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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How does an antisense RNA molecule restore protein function in CF patients?

I am researching a treatment for cystic fibrosis (CF) called Eluforsen and I am trying to understand the mechanism by which an RNA molecule can restore proper protein function. In many research ...
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How do I identify and then isolate a Gene that codes for a particular observable phenotype

How do I identify and then isolate a Gene that codes for a particular observable phenotype. It is a novel bacteria and I do not know the gene sequence or the protein that it codes for.
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Is the total of all human DNA (23 pairs) the longest of all species?

The human DNA molecule is about 2 meters in length. See here. We have 46 of them, so in total 82 meters. In this article it is said that the genome of the Protopterus aethiopicus (a.k.a The marbled ...
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How is the exogenous DNA protected from degradation during bacterial transformation?

During transformation, a bacterium can take up DNA from its environment. A small fraction of bacterial species are known to be naturally competent, meaning that they can engage in this sort of ...
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Is the lac operon repressed in the presence of both glucose and lactose?

In the presence of both sugars (glucose and lactose) will there be repression of the lac operon completely? I know that more glucose means less cAMP --> less CAP --> less positive regulation, and ...
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Are all carcinogens mutagens?

I assume that all carcinogens must be mutagens, but I've read that this is not the case. However, I can't find any good examples or an explanation of why it is not the case. How can a non-mutagenic ...
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Are all mutagens carcinogens?

Not all carcinogens are mutagens. Alcohol and estrogen, for example, does not damage DNA. It's one of the assumptions of the Ames test that mutagenicity implies carcinogenicity, but is this always ...
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Can bacteria pick up lethal plasmids?

I am sorry if this question is too general, and does not have any concrete answer. I was explaining to my non-biology-background friend about plasmids and how they are picked up by bacteria from the ...
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How does a lymphocyte produce an antibody from an antigen?

I am studying the immune system, and I have a question about the inner workings of antibody production in lymphocytes. As I understand it now, lymphocytes are able to create antibodies based on ...
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How do cis-regulatory elements and trans-regulatory elements behave differently?

Suppose you are working with an operon in a diploid organism. I'm looking for either a biochemical or genetic explanation. What I'm having trouble with mainly is understanding how something would ...
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How do mutations of viruses lead to drug resistance?

For instance, after starting zidovudine monotherapy against HIV, resistance develops against the drug because of a point mutation in the RNA transcriptase enzyme to which the drug binds. So how does ...
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How do homologous pairs find each other

If I'm not mistaken the only time homologous pairs of chromosomes need to find each other is during gamete formation in preparation for crossover recombination. How do they find each other?
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Insertion Confirmation Cloning Strategy

So I am in a bit of a time constraint. Essentially, I inserted a DNA fragment via molecular cloning which contains a unique RE site. I need to confirm whether my colony has or does not have the ...
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Question about alternative polyadenylation

I know that alternative polyadenylation creates different transcript isoforms. My question is whether alternative polyadenylation ever results in differences in the terminal/last exon? The only case I ...
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How can you band wheat chromosomes using Giemsa dye?

I am working with wheat chromosomes and trying to stain the chromosomes. However, during staining with Giemsa dye chromosomes appear totally dark. I'm not sure why this might be. Anyone have any ideas?...
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What prevents mRNAs that are localized to a specific part of the cell from being translated before they reach their destination?

One of the methods of mRNA localization, for example, is random diffusion of mRNAs where the mRNA binding proteins are localized to a certain part of the cell. However, I was taught that the ribosome ...
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Parthenogenesis vs. Fertilization. Is a polar body different from an egg?

In Parthenogenesis that happens by automixis "the replication of an egg by meiosis and the transformation of the haploid egg to a diploid cell occur by fusion with a polar body." =https://www....
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What is a holocentric chromosome?

I was doing this question that asked: "How many centromeres does a typical chromosome have?" I thought one and the answer was:"One, except for holocentric chromosomes." So then what are "...
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Can Cas13 be used with multiple crRNAs in the same reaction?

CRISPR-Cas13 equipped with crRNA (complementary to transcripts of interest) can be designed to target ssRNA transcripts in cells. Upon successful crRNA and ssRNA binding, a fluorescent domain on ...
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Prokaryotes Genome

What function of repetitive sequences of Prokaryote? I see a gap (intergenic region) between 2 coding strand. But just only a single origin region in Prokaryotes. How it can transcription coding ...
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How can we say that a gene is spacio-temporally regulated?

Gene expression is depending on the space and time of the cell. How can we distinguish the function of a gene without a chance of changing its expression? And also how is it possible to find the exact ...
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What controls specific gene silencing during cell differentiation?

I am intrigued by the fact that all cells of our body use the same DNA. How do the cells differentiate during the post fertilisation divisions? I read about gene silencing, which can be an answer to ...
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Study on Introns?

I am curious whether there has been a study done on the effects of removing introns. Specifically, what happens if you genetically edit a eukaryote genome to no longer contain introns? Or maybe just a ...
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Difference between CDS and cDNA

What is the difference between Coding Sequences (CDS) and cDNA? Are Coding sequences the sequences that is transcribed to mRNA and cDNA in contrast DNA obtained by reverse polymerization of matured ...
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Do telomeres appear at just one end of the chromosome?

I have just studied DNA Replication for my Biology Class and I have this question that leaves me stuck, though I have tried to figure it out myself. During telomere replication, I am aware Telomerase ...
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Methods: Homologous recombination and retroviral infection

I'm looking for a textbook that explains these methodologies: Use of homologous recombination to insert a gen-cassette into another organism's gen. Use of retroviral transduction to deliver genes ...
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What are the potential dangers (if any) facing the twin girls recently born in China with their CCR5 gene modified?

According to this Nature news article, a Chinese researcher claims to have made the world's first genome-edited baby using the popular CRISPR–Cas9 genome-editing tool. A gene called CCR5 was modified ...
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During DNA foot-printing, what is the purpose of radioactively labeling only one end of the DNA fragment?

I read that during DNA foot-printing analysis, DNA is radioactively labeled on one end before being cleaved by DNase 1. I understand that it is labeled so in order to locate the fragment on a gel, but ...
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what is minimal promoter and what is basal promoter?

what is minimal and basal promoter and what are their elements and what is the difference between the two?I'm confused. searched a lot, but didn't found any satisfactory answer. please help
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What causes the elongation of Genome down the evolutionary time line [closed]

Theory of natural evolution says that complex life forms arose from simpler ones e.g. starting from Eubacteria to modern day multicellular eukaryotes. {If we try to reduce these changes happening at ...
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How many recombinations occur in an average human chromosome?

And is it a different number depending on which chromosome we choose (disregarding the change of this probability due to the differential size of the chromosomes)?
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What Ultimately Controls DNA Transcription?

Transcription of DNA and further splicing of mRNA is regulated by various transcription factors, small nuclear RNAs and so on; similarly such related mechanisms as transposition of transposons. All ...
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Are mutations a source of genetic variation?

Here is a question from the book SAT II Success Biology E/M (where the SAT is the exam taken by the American high school students): Which of the following statements is true about mutations? (A) ...
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Difference Junk DNA and Pseudogenes [duplicate]

1-Are Pseudogenes and Junk DNA both Non-Coding DNA or they are different entity? How much Pseudogenes & Junk DNA do we have respectively? 2-I read that Non-Coding DNA has functions, my question ...
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Is brachydactyly due to mutation?

I have this so called "clubbed thumbs"also known as brachydactyly. It is of D-type. I searched for it on internet and found that it is a dominant inherited disease. But to my surprise,none of my ...
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Is the genetic term “polycistronic” still used in modern biology?

Is the term "cistronic", meaning an ORF on a mRNA, still commonly used in modern genetics? I´ve seen "polycistronic" being applied to prokaryotic mRNA in old textbooks, but I´ve rarely stumbled upon ...
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Can different cell lines of same type symbolise samples from different patients in ChIP-seq?

Can I simulate different patients by using different cell lines of the same cell type and from the same tissue? Can I also study apoptosis in an immortalised cell line? I have a gene X (transcription ...
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What advantages could there be for using the unseen variant chosen by He Jiankui instead of the naturally occurring CCR5-∆ 32 mutation?

Jennifer Doudna mentioned in https://youtu.be/9Yblg9wDHZA?t=2566 on 2019-02-21 that He Jiankui introduced an unseen variant of the CCR5 gene when gene editing the twin humans Lulu and Nana. What ...
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Confusion about result of monohybrid cross in Mendelian genetics

I was studying monohybrid crosses in genetics where the character considered is stem height. Whenever I came across punnett squares, I used to calculate the probability of the genotype of the ...
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How evolutionarily conserved are UTRs?

Coding sequences of genes have a certain degree of evolutionary conservation, so that comparisons based on sequences (BLAST, HMMER etc) can be informative. Generally speaking, the more two species are ...
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Is there an Exit site (E-site) on the eukaryotic ribosome?

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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What is the role of CRISPR-dCas9 in gRNA-dCas9 transcription regulator complexes?

In this paper1, 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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Are all fusion genes somatic in origin or can fusion genes be germline?

Fusion genes should have an origin.These are essentially hybrid genes that are translocated in its entirety. Eg. BCR-ABL, EML4-ALK are known to be implicated in cancer pathogenesis. Do these ...
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How to determine if two mutations in a gene are on the same or different alleles?

I would like to know, except a familial study, is there another way to determine if a mutation/variation is cis or trans (i.e. on the same or different alleles)? For example by sequencing technique or ...
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Number of DNA strands per chromosome

As I was reading Griffith's Introduction to genetic analysis this evidence was provided for single DNA makes single chromosome. Eventually geneticists demonstrated directly that certain chromosomes ...
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What is the difference between DNA vs RNA Editing in the context of gene therapy?

As a someone with beginner knowledge on biology, I have come across the terms "RNA editing". Take this paper for example : RNA Editing with CRISPR-Cas13 From my understanding, DNA -> RNA -> Proteins ...
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Are epigenetic modifications the most stable mechanisms for cell differentiation?

Wondering what the general take is on what are the molecular mechanisms that are mostly responsible for cell type differentiation stability; ie, for a cell's identity to actually become 'locked in' ...

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