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

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Extending a small fragment of DNA

Is there a way to extend a small fragment of DNA, say 150 bp, by making copies of itself and attaching each copy of that small fragment to the end of that 150 bp sequence? For example, I want a 1 ...
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2answers
128 views

In DNA repair, how is it determined which strand contains the error?

DNA replication is more accurate than transcription (or RNA replication) because mechanisms exist for proof-reading and repair of DNA, but not for RNA. Consider a segment of a DNA strand, AGTC. Its ...
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1answer
48 views

Correlation of non-coding DNA with coding DNA

I sequenced the first exon of the MC1R gene of 15 labradors (genomic DNA) to look for the loss-of-function mutation (C.916C>T) and as expected, it was where it should have been (916th base pair). As i ...
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1answer
30 views

Does mechanotransduction of cells play a role in the biocompatibility of titanium?

What exactly is mechanotransduction as the information varies between sources. Some sources indicate that mechanotransduction is the underlying principle where cells pull on the surface they grow on ...
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1answer
18 views

Are the subordinate genes of a repressed operon really “turned off”?

Operons are often described using all or nothing language. A repressor binding to the operator is usually presented as "turning off" the regulated genes. Case in point, Scitable at Nature.com says: ...
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14 views

What is the difference between desert and migratory locust?

I know both are species of short horned grasshoppers and belongs to the orthoptera order, Acrididae family and so on. But what is the difference between desert and migratory locust? How do we ...
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2answers
44 views

DNA replication in E.coli

What is the difference between replication and to divide? My A level bio book says that it takes 20 min for E.coli to divide and in next page it's written that E.coli completes replication within ...
2
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0answers
43 views

Amplified Fragment Length Polymorphism (AFLP) primers

I am trying to blast AFLP primer sequences to the genome to find the locations of the AFLP markers. However, I can't seem to find full alignments for the primers on the genome. For example, in the ...
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13 views

Hybrid vs introgression zone in natural populations

In the book An Introduction to Molecular Ecology, the authors are saying that introgression is the diffusion of alleles from one population or species into another as a result of interbreeding ...
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1answer
416 views

Lac operon: How can lactose enter the cell in the absence of lactose permease?

My textbook states that lactose permease...transports lactose into the cell and When lactose is added to the growth medium, the lactose molecules bind to the other site on the repressor ...
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3answers
711 views

To what extent is the genetic code more than just a code?

It is worth specifying the exact meaning of "code" in this question. A code is a map from one space to another space with which it has no algorithmic connection. Thus representing 321 as 0x141 is not ...
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1answer
54 views

Cell cycle-regulated genes and mRNA

I am a mathematician and my knowledge about biology is close to zero. I am reading a bioinformatics paper and I would like to understand a bit more about the biology task they are talking about. I ...
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1answer
34 views

Distribution of Exon and Intron Sizes

Goal I am trying to get a distribution of Exons and intron sizes in Three-Spined Stickleback (Gasterosteus aculeatus). Data downloaded I downloaded some data from Ensembl. More precisely, I went ...
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2answers
163 views

Redundancy of the genetic code

One particular codon codes only for one amino acid, but an amino acid can be coded for by several different codons. Now according to the genetic code, the codon UUU ...
2
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3answers
69 views

T7 vs pBAD promoter strength

How do pBAD and T7 promoter strengths compare when pBAD is induced under conditions which would lead to its highest strength? Are there any papers that compare the two inducible promoter systems?
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0answers
12 views

Similarity between lncRNA and Enhancers

Please read it carefully. Question below is purely based on computational experiments: I have been running an analysis algorithm (pretty new one) on lncRNAs and its showing pretty much the same ...
7
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3answers
104 views

Following DNA replication during S-phase of the cell-cycle, are all genomic regions subjected to the same stringent level of DNA-Repair?

To my (limited) understanding, there are 2 main ways that mutations can occur in DNA: Environmental (UV, etc) and mistakes during cell division. I was wondering if there is a mechanism that can give ...
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3answers
66 views

Can a single strand of mRNA form different polypeptide chains?

My book has a statement: A single strand of mRNA is capable of forming a number of different polypeptide chains. In my opinion this statement is wrong because a single strand of mRNA will have same ...
3
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1answer
665 views

Can DNA & RNA be considered as nature's programming language?

The final frontier of Biological Sciences could be considered understanding the effects of variation in the DNA (and RNA). If after fertilization the DNA of the zygote could be genetically ...
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0answers
28 views

How do expression levels change along lineages?

Is there any general trend between gene expression levels (or transcription levels) and cell lineages? For example, I would naively expect that stem cells express less genes as they have the ability ...
5
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3answers
77 views

Cell cycle selection

Is it possible to select from colonies only cells which are at a certain stage in the cell cycle? E.g. if I was trying to analyse expression of a number of genes during different stages of the cell ...
3
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1answer
2k views

Does a woman contain all the genes needed to make a man?

I know the answer of inverse is at here, but how about this question? I also read this question, can I imply to human that a woman can also contain all the genes needed to make a man? Edit: I ...
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1answer
65 views

What are Codominant vs Dominant Genetic Markers?

When talking about types of genetic markers, the adjective "dominant" and "codominant" are often used. I don't fully understand their definitions and found contradicting definitions. Foll and ...
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23 views

How does epigenetics affect the birth conditions via alcohol?

Recent study has shown that epigenetics can play role in male-caused infertility and it cites for example studies which showed an enhancing of silent genes when drinking alcohol. Since the study ...
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1answer
38 views

What are the significances of chromosome mapping? [closed]

The few point that I have come across are: The following are the significances of chromosome mapping: Chromosome maps help identify the location of gene of interest on a chromosome for genetic ...
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2answers
1k views

How does RNA transcription determine which half of the DNA to use?

I feel that I might have a complete misunderstanding here. If DNA has two strands, how does the machinery of RNA transcription determine which one to transcribe?
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38 views

When was the first exception to Mendelian genetics discovered?

In addition to the the question in the title I'd like to know , how scientists reacted to the exceptions?
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1answer
57 views

Is there selection against long proteins and long genes?

Background thought Titin and TTN Titin is the largest protein in the human genome with 33423 amino acids. Titin is coded by the gene TTN that must be at least $3 \cdot 33423 \approx 100kb$ long. ...
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33 views

How do I know whether or not a nuclear gene is single copy?

As a part of a phylogenetic study, I need to find a nuclear gene that meets the following requirements: Single copy gene; Highly variable gene; Gene longer than 400 bps; Gene that gives information ...
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3answers
43 views

Difference between null and recessive allele?

I get that in a single gene locus, an individual can have RR, Rr, or rr as the two alleles ...
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0answers
13 views

Developing cDNA for RDT

Eukaryotic genes cannot be inserted in prokaryotic hosts for making recombinant proteins, since eukaryotic genes are split genes and their hnRNA must first be processed to functional mRNA before ...
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16 views

Does any specific property decide which DNA strand acts as leading strand template?

Of the two strands of DNA, the one that unwinds in the 3' to 5' direction constitutes the leading strand template, with the other strand of course acting as the lagging strand template. Is there any ...
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3answers
616 views

Are the number of base pairs in a given chromosome same between different individuals?

This is a basic question but I couldn't find an answer through a web search; hopefully this is the right place to ask. Is the number of base pairs in a particular chromosome the same in all ...
6
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3answers
323 views

Are some non-coding RNA spliced?

Are some non-coding RNA spliced like mRNA? I tried to find some information but I don't find anything...
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2answers
64 views

What is meant by “Expression” of Non-Coding RNA?

I was having a look at lncRNAdb and its help says: The ENCODE project gene annotation list, GENCODE, has predicted that the human genome contains 14,470 lncRNAs whereas only a small proportion of ...
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1answer
30 views

What do arranging and assigning mean in sequence annotation?

Please could someone explain these lines to me in a simple way These sequences were then arranged based on some overlapping regions present in them. This required generation of overlapping ...
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79 views

Is there a term for when a detrimental gene can be positively selected for because of linkage to a very fit gene?

Let's say that some piece of DNA would be subject to extreme negative selection if it were independently inherited, but it is very closely linked to an extraordinarily fit gene, and so the complex it ...
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1answer
38 views

What is a “noninvasive” biomarker for a disease? [closed]

What is a "noninvasive" biomarker for a disease? I know what a biomarker is, but what makes it noninvasive?
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2answers
64 views

What makes DNA sequences most different/recognizable from a biological perspective? [duplicate]

We can pretty easily quantify the amount difference between two different strings/sequences of characters. For example, if we take the words trebuchet and trebucket, we can say they have a Levenshtein ...
4
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3answers
102 views

Do transcripts always start and end with exons?

I realized that in all cases of "RefSeq Genes" annotations of hg19 I looked at spliced transcripts start (and end) with an exon. From the annotation there is no evidence of any sequence upstream or ...
0
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1answer
57 views

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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0answers
20 views

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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0answers
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 ...
0
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2answers
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. ...
2
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1answer
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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1answer
89 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 ...
3
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1answer
79 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 ...
7
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3answers
14k views

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 ...
5
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1answer
81 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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3answers
701 views

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?