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33 votes
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Do men and women have the same number of genes?

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 ...
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33 votes

Do all humans have an identical nucleotide sequence for certain proteins, e.g haemoglobin?

It is highly unlikely that there exist any protein that is made from completely identical nucleotide sequences across the entire human population. There will certainly be regions within a gene that ...
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23 votes
Accepted

Do all humans have an identical nucleotide sequence for certain proteins, e.g haemoglobin?

Humans have many variants There is variation. The project I use to help understand this natural variation is gnomAD. Using VarMap and a slightly out of date gnomAD file, I counted 16007805 protein-...
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11 votes
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Father with mutated mtDNA- why isn't his offspring at risk?

...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'...
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11 votes
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Why does human chromosome 19 have the second highest number of protein-coding genes?

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 ...
11 votes
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Why is the start of my coding sequence ATG and not TAC?

This image from the Kahn Academy article 'Overview of transcription' might help: Essentially, the sense/coding strand of the DNA encodes the sequence that is transcribed. The RNA polymerase binds to ...
10 votes

Is a gene located in the sense or the anti-sense strand?

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 ...
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10 votes

Genes and Intelligence

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 ...
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8 votes
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Stop codons and exons?

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 ...
  • 17.5k
8 votes

Interpretation of picture of human chromosomes

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 ...
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8 votes
Accepted

Interpretation of picture of human chromosomes

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;...
8 votes

Do all humans have an identical nucleotide sequence for certain proteins, e.g haemoglobin?

At the whole-gene level, there is likely no absolute conservation of any human protein-coding gene at the population level, though there might be complete conservation between individuals. Keep in ...
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8 votes
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How do gene locations change during crossing over events?

It depends on the regions of sequence homology between the two chromosomes. Crossing over occurs through pairing of homologous regions. If there's a substantial stretch of chromosome without a ...
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7 votes

Which information can be obtained from a list of gene names?

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 ...
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7 votes
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Gene and alleles

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 ...
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7 votes

What determines the efficiency of electron production in photosynthetic bacteria?

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 ...
  • 1,279
7 votes

What is the difference between non-coding and intergenic regions?

"Intergenic" is, well, an embarrassment, though it can be hard to avoid. Intergenic means, literally, between genes. Genes are, as you'd expect, genetically defined as regions of the ...
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6 votes

Are eukaroytic promoters located in the 5' UTR region?

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 (...
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6 votes

Sheep vs. Furry animals

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 ...
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6 votes
Accepted

Whole Genome Sequencing vs Whole Exome Sequencing

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 ...
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6 votes

What are multiallelic genes?

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 ...
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6 votes
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Explain a gene network to a first year undergrad

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, ...
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5 votes
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What does it mean to "map the human genome"

So, the very first map of the human genome was of a few pooled samples with a single nucleotide called at each position. This is basically okay, though, because humans are 99.9 (with possibly a few ...
5 votes

Father with mutated mtDNA- why isn't his offspring at risk?

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 ...
5 votes
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How can human infants express chymosin with only a pseudogene at their disposal?

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....
5 votes

Which information can be obtained from a list of gene names?

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 ...
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5 votes
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What is the difference between "physical interaction" and "genetic interaction"?

Physical and genetic interactions are described in the help wiki, accessed via the top menu bar on the page you linked to. Physical interactions refer to experiments where the gene product (protein) ...
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5 votes

Stop codons and exons?

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 ...
5 votes

What does the gene name "lexA" stand for?

According to this website, it is a mnemonic for "lambda excision". I have also found this usage in scientific literature (eg. Harami et al., 2013). However, neither of these sources ...
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5 votes

What does the gene name "lexA" stand for?

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 ...
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