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33

It is true that the Y chromosome is shorter than the X chromosome and that there are more genes on the X chromosome. Do men have fewer genes? One could (mis)understand three things in the expression "number of genes". Number of gene copies (see Copy Number Variation) Number of genes Number of alleles Thanks to @GerardoFurtado for correcting my ...


11

...would then be his offspring at risk? Why? No. Generally speaking, fathers do not pass on their mtDNA (Mitochondrial DNA). Why? Because the mitochondria present in oocytes (egg cell) is the mother's, as every oocyte directly inherits the mother's mitochondria when they are made in the reproductive organs. The mitochondria that the sperm from the father ...


11

This Nature paper from 2004, by Jane Grimwood et al. goes at least a long way towards giving an answer to the question of the OP. In short: there were inordinately many duplications, especially during an event 30-40 million years ago, as well as during a much more recent event. These duplications are, uncharacteristically, predominantly intra-chromosomal ...


8

Take a look at this schematic of a mature mRNA. [source] The coding region (ie the part that is translated) is between the start and stop codons, but the 5' and 3' untranslated regions (UTRs) are also transcribed by RNA polymerase; these are part of the first and last exons, respectively. The transcription start site is labelled right in front of the 5' ...


8

The picture can be a bit misleading because it represents 22 autosomes (autosome = non-sexual chromosome) while there are 22 pairs of autosomes (so the homologous chromosome is not represented). And it represents the whole pair of sexual chromosomes (the individual is a male). homologous chromosome For each autosome represented, there is another one which ...


8

Since I have used more than 1 image in my answer; with numbers starting from 1; I'll call your provided figure as figure-0 What is shown in following picture? Though the image showing many things; in overall it is an image of a set of chromosomes; seemingly almost certainly from human. The chromosomes has been stained with a banding method (though I'm ...


7

I would suggest searching the name in any trusted genetics database such as NCBI's GenBank (http://www.ncbi.nlm.nih.gov/genbank/). You can just Google search it, but it may take a little longer to find useful information that way. I hope this helps and good luck with your research, CDB


7

Alleles are basically subtypes of a gene. At the time of Mendel, the molecular nature of inheritance was not known so the original definition of gene refers to "some" inheritable molecular entity inside the organism that is responsible for a trait. Alleles are different "flavours" of a given gene. For example there is a gene for flower colour, there can be ...


7

You may or may not consider this an actual answer to your entire question, but it's interesting nonetheless. A physicist friend of mine did some work recently modelling the quantum dynamics of photosynthetic complexes, and their coupling constants for passing energy throughout the photosystem. His results showed that, (and I believe this is in agreement ...


7

A few words on genomic prediction No complex trait is 100% heritable, hence no prediction based entirely on DNA would ever be perfect. With that said, predictive genomics is progressing at a quite amazing rate right now. So while predictions can be nowhere near perfect, it is getting possible to make DNA predictions that correlate substantially with ...


6

Most promoter elements are not a part of the mRNA sequence. They are upstream (towards 5') of the transcription start site. However, a certain class of promoters called downstream promoter elements (DPE) can overlap with the geneic region. These elements have been reported to lie at 29-33bp upstream of the transcription start site and widely employed, in ...


6

Fur, wool, and hair are all made of keratins. To the best of my knowledge wool and fur are separated arbitrarily, based on the properties of the fibres. This arbitrary division allows rabbits to have fur but selective breeding has produced angora rabbits, which have wool. The opposite should be possible, with time you could breed a sheep that has fur. ...


6

WES, almost certainly. First of all, the vast majority of phenotype-causing variants are found in exons. For most analyses that are looking into disease causing mutations, WGS is pointless. It only makes your analysis harder and doesn't actually add anything useful. If you know you're interested in CNVs, that's different. CNV detection is hard in general ...


6

More than two alternative forms (alleles)of a gene in a population occupying the same locus on a chromosome or its homologue is known as multiple alleles. Multiple alleles arise due to mutations of gene.A gene can mutate several times by producing a series of alternative expressions.Different alleles in a series show dominant-recessive relation or may show ...


6

None of the highlighted regions in your figure, is a gene. A gene is a section of DNA which gives rise to a product. Basically, a gene has an orientation (5'→ 3') i.e. it is essentially a single stranded region. However, the strand that mechanistically contributes to RNA synthesis (template) has the reverse-complementary sequence of the gene (in other words, ...


5

TL;DR: Ubiquitin. Occasional occurrence of paternal inheritance of mtDNA has been suggested in mammals including humans. Clearly, spermatozoa have mitochondria; they make the energy needed for motility. Paternal mitochondrial DNA (mtDNA) does enter oocytes. It is a persisting fallacy that only maternal mtDNA is present in humans because only oocyte ...


5

TL;DR: Chymosin is similar to pepsin and I couldn't find any evidence of functional/expressed chymosin gene in human genome. It seems like a common misconception that chymosin is functional in humans. Already in 1940s it has been shown that rennin (aka chymosin) is absent from "gastric juice" in adult humans. Genetically there is only pseudo-gene for ...


5

Was getting long in the comments. In light of your comments, you might be interested in Gene-set enrichment analysis (GSEA). You can do a GSEA using your set, the other one coming from reference databases such as MSigDB (see here). You can categorize your list by gene families using this technique for example. You can get an idea of what cellular process ...


5

You mix up translation and transcription. Transcription creates mRNA from DNA template. Transcription also includes splicing, that is excision of introns so that mature mRNA contains only exons. In your example it goes like that: DNA (chromosome): ---A----B--...--Dstop---E--- premature mRNA: A----B---...---Dstop--E---polyA mature mRNA: AB..DstopE-polyA ...


5

Little harm comes from ABO incompatibility (that would have been a major problem with reproduction.) Rh incompatibility is more dangerous, though. If a fetus is Rh+ and the mother is Rh-, when there is mixing of maternal-fetal blood (at birth, but sometimes before that), the mother will form antibodies to the blood cell surface antigen. It doesn't usually ...


5

So the term allele is a broad one, and simply refers to the different versions of any piece of DNA in circulation in the gene pool - it doesn't need to refer to a gene. I can talk about the alleles at a random place in the genome. But if we proceed with your question and ask - 'do nonsense mutations within coding genes also lead to the creation of different ...


5

You are absolutely correct that many traits are not "digital", but "analog". In genetics, these are usually called quantitative traits. Such traits generally do not follow Mendel's laws of inheritance, but are said to have "complex inheritance". Most traits (phenotypes) in biology at the level of whole organisms probably have complex genetics; height is a ...


5

Yes, all cells contains the same genome. This is because, for a given individual, all of its cells comes from the zygote, a singular cell formed after fecondation of the maternal ovum and paternal spermatozoa, through repeated cell division (mitosis). This is a process which replicates quite exactly the genome that will be passed to the newly formed cells. ...


5

Most the genome is not coding for proteins. Here is a pie chart of what the human genome is made of As you can see, only 1.5% of the human genome codes for proteins. The term gene is often a bit vaguely defined but if we assume that a gene is all the exons, all the introns and all the regulatory sequences, then 25.5% of the human genome are genes. So, yes ...


5

Usually a promoter is not considered a part of the gene. Distal regulatory elements qualify even lower for being considered a part of a gene because they can regulate many genes simultaneously. Basically, a geneic region starts from the transcription start site (TSS) and ends at the terminator (or polyadenylation/cleavage site in eukaryotes). If a gene ...


5

There is no single answer, because networks (or graphs, as they are called in discrete mathematics) are flexible tools that can be used to model all sorts of relationships between genes, transcripts, proteins, or other entities in biology. (And networks are useful models in many other disciplines too, like sociology.) Depending on the type of network you're ...


5

The database you are looking for is ensembl [Yates (2016)]. Go here and chose Customise your download. There you can select a dataset (e.g. genes and then specify human genes - currently uses build GRCh38; you can also go the same way here to do the same for hg19/GRCh37). After chosing your dataset, you can click on Attributes to specify what to include ...


4

According to this website, it is a mnemonic for "lambda excision". I have also found this usage in scientific literature (Harami et al., 2013). However, neither of these sources reference anything and I cannot find any defining paper. Almost all papers simply refer to it as lexA. As far as I can find (it's difficult to dig up these old papers), this is how ...


4

I'd go with Lambda Excision A. Terms like lex or rec often stand for what'd be termed a mnemonic, where for example rec may stand for recombination, or umu for UV mutator. The naming conventions can be difficult. Edit: A 1981 study by Roger Brent and Mark Ptashne notes some data from initial studies that showed the lexA repressor downregulated a number of ...


4

There is nothing intrinsic to DNA methylation itself that requires it to repress transcription. Simply, it affects sequence recognition by proteins. CpG methylation can prevent transcription factor binding and/or recruit proteins that inhibit transcription, either competitively or through chromatin condensation. This is why it's generally associated with ...


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