Genetics is the branch of biology that deals with the transmission and variation of inherited characteristics.

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X-inactivation in ovaries

Background In all eutherian (mammals excluding the marsupials), the female (who is $XX$ for the pair of sexual chromosomes) inactivates one of her $X$. This is called dosage compensation. This ...
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What's a non-allelic gene?

Non-allelic or non-alletic I stumbled across the term in my Human Genetics textbook. It didn't explain it there, and a quick google search only showed scientific papers that refer to 'recombinations ...
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89 views

What triggers DNA to produce proteins?

What is the trigger for DNA to produce proteins or RNA? I have found enough material to study the inner workings of the cell and DNA; but, I can't find an explanation of the mechanics the cell uses ...
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Is there any source for raw data of SNP genotype frequency?

On sites like SNPedia, some pages contain the frequency of the SNP in question in different populations, based on published research. I'm trying to write a script that takes 23andme data and compares ...
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98 views

In a vertebrate chimera, are particular organs homogenous genetically?

I have read that a chimera is an organism with two or more sets of DNA, with every cell having one of the sets. Is it possible and common for the two or more sets to be present in the cells of a ...
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357 views

T7 promoter leakiness

Can a gene be expressed under the T7 promoter in an E. coli strain (e.g. DH5 alpha), which does not have the T7 polymerase gene encoded in its genome? In other words, is T7 promoter leaky? To be ...
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Mechanisms of Gene*sex / Genotype*sex interactions

I'm looking for suggestions of the mechanistic level at which genotype/gene * sex interactions can occur. These give different phenotypes from the same geneotype dependent on the sex they are ...
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35 views

How was the cama's life expectancy computed?

A cama is a hybrid between a male dromedary camel and a female llama. The first cama was born on January 14, 1998, yet on the Wikipedia page it is said that a cama's life span is 30–40 years. How was ...
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157 views

Genetic expression in interspecific hybrids

Referring to interspecific hybrids, I have the following two questions:- Quoting from wikipedia:- The offspring of an interspecific cross are very often sterile; thus, hybrid sterility ...
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What is the frequency of double-hets between parent and child?

Say both parent and child are genotyped for all SNPs. In this setup we are only looking at variant positions between one parent and child - so neither parent nor child are homozygous reference (no ...
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effect of background selection on promoter regions compared to distant enhancers?

Has anyone looked at the effect of background selection on the levels of conservation of promoter regions compared to distant enhancers? Do promoter regions have a higher conservation due to ...
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Determine which gene is in the middle complementation [duplicate]

Possible Duplicate: Crossing mutant strains on minimal media problem I'm studying this problem for my genetics final: My Attempt: The answer for part B is met2 and the answer for part C ...
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Can the third sex be categorized as Male or Female?

Hijra are people who have a penis (not sure if sexually active) but look much like a female (perhaps for some feminine biological property). Wikipedia says they are "physiological males who have ...
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319 views

Why is the strength of genetic drift inversely proportional to the population size?

I saw a concept on the Internet that says "the strength of genetic drift is inversely proportional to the population size". I don't know why they are inversely proportional? Can somebody explain? ...
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Evolutionarily speaking, why do humans have 46 chromosomes

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Monkeys, chimpanzees, and Apes have 24 pairs (twenty-four pairs), for a total of 48. What caused humans to have 46? ...
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310 views

How can fruit flies and mice share the same gene that says to build an eye if they evolved separately?

I saw a documentary where they inserted the gene of a mouse that basically is the starting "build an eye" command into a fruit fly, and a fruit fly eye grew. My question is, if eyes of different types ...
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148 views

Hardy Weinberg Equilibrium problem

In a small tribal population, the frequencies of two alleles A and a at a particular locus were 0.3 and 0.7, respectively. However, not all the individuals with genotype aa could live up to the ...
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73 views

Can genes that activate transcription factors also called be called transcription factors?

If the sole known function of a gene is to activate a transcription factor, would that gene also be considered a transcription factor, or is there a word for such genes that are further upstream on ...
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725 views

Difference between mice and rats

What is the actual biological difference between mice and rats? Are they actually the same thing with two different names depending on appearance (are they all mice for instance and we call the larger ...
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350 views

How to calculate relatedness in haplodiploid organisms (mainly full sisters and full brothers)?

I have tried to calculate the relatedness for haplodiploid organisms, but cannot understand the calculations behind full sister and full brother. (taken from Wikipedia: haplodiploidy I have managed ...
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141 views

Why has grey hair evolved?

A vast majority of humans get at least some grey hair as they age. As far as I know this applies to both genders and all races. Presumably this means that at least some grey haired humans have ...
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441 views

Is there variation of AT/CG ratio along species?

Chargaff's rules say that the number of Adenine of the number of Thymine in a genome are equal (nA=nT) and similarly nC=nG. This makes obvious sense knowing that C binds to G and A to T. But what ...
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329 views

What hair color will result in someone inheriting both blond and ginger genes?

Both the genes for blond hair and ginger hair are recessive, so they need both parents to give the same gene for it to take affect. What happens when a person has 1 copy of a recessive gene and ...
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220 views

Macroevolution vs. microevolution

Where is the line usually drawn between macroevolution and microevolution? I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes ...
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Theoretically, what technique would one use to modify a virus so that it only affected a subset of the population?

I'm writing a novel and i would like to know some of the equipment and techniques involved with modifying a virus. Is it feasible for a virus to be engineered to only affect certain people? It ...
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How Much Longer For The Gene For Blue Eyes?

In the year 1900 roughly 50% of the people in the United States were homozygous for the gene for blue eyes. By 1950 the number had dropped down to 30%. Just now, (2013) barely 12% of the people living ...
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Number of genes required to sustain life

Are there estimates of the minimum number of genes required to sustain life? In what I mean by life here, I don't include viruses.
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Which part of a female mantises's DNA causes her to be a few times larger than a male mantis?

Which part of a female mantises's DNA causes her to be a few times larger than a male mantis? Do other species have that part of DNA?
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101 views

Help explain multi alleles in terms of actual genetic code

I understand that someones genetic makeup at an allele is usually denoted as (AA,Aa,aa). That means that instead of an A-T pair you get a C-G pair on none, 1 or 2 copies. Now, what exactly happens ...
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125 views

What is the most genetically simple organism except viruses?

What is the most genetically simple organism (except viruses) on this planet? By simple I mean the least number of genes.
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450 views

What species have had their genomes sequenced/are being sequenced?

The human genome project released it's first complete genome nearly ten years ago. Since then many species have also been sequenced. I am trying to find a list of completed (and possibly ...
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When can I assume individuals marrying into a pedigree are non-carriers?

If I'm not told that they're non carriers, and if I don't have proof of their geneotype based off of progeny, when can I assume they're non carriers for a trait?
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How common is bacterial mediated transformation? In plants? In animal cells?

The most common method to transform plants is by soaking plant tissue in cultures of agrobacteria (this is not their current classification) which transfer DNA into the plants. Is lateral gene ...
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How can GMO contaminate biologic plants?

Let consider two use cases : I am the only farmer within a 200km radius. I first grow GMO plants. A few cycles later I decide to grow bio plants, so I uproot all of the GMO plants and plant fresh ...
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XXY (Klinefelter's) & Trisomy 21 & X-inactivation

I read that X-inactivation doesn't tend to happen in males, but then when someone is XXY, they are a male because of the Y. However these individuals tend to live. So does that mean that ...
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122 views

Do there exist publicly available Genome sequences of a family?

I would like to explore the genome sequence of a publicly available genome sequences of a family (like mother, father, son, daughter...). If such human genome sequences are not publicly available at ...
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127 views

Question about Autosomal Recessive Alleles

I had a homework question that I could not figure out. It states: A woman has cystic fibrosis in her family and did not want to have a child that suffered from the disease. She and her spouse ...
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271 views

Are identical twins exactly the same?

http://www.scientificamerican.com/article.cfm?id=identical-twins-genes-are-not-identical According to this article some identical twins show differences with respect to their copy number variants. ...
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703 views

What does phasing mean?

What does phasing mean in genetics/informatics? I've heard that a phased file is a file that has genes separated by chromosome, but can someone give a concrete definition of what phasing actually ...
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303 views

Detecting Introns and Exons

I know that when RNA is transcribed from the original strand of DNA it contains introns and exons, and that the introns are spliced out of the strand to provide genetic diversity. However, what I ...
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224 views

How might gene clusters like the lac operon evolve?

The obvious answer for a gene cluster is gene duplication and mutation of one or both genes. But the genes in the lac operon seem not be so functionally/structurally similar (as compared to the Hox ...
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Microbiome Data

How is it possible to access microbiome data like that found here? I'd like to perform analyses on similar type of data, but cannot find OTU data like that at the Human Biome Project. Thanks for any ...
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202 views

Extreme examples of protein translation/use coupling/decoupling?

What are known extreme examples of protein translation/effect coupling/decoupling? For example, examples of proteins that are immediately used at the time the have been translated and vice versa, ...
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62 views

Do human visual functions degenerate due to genetic factors or by external factors?

Does eyesight primarily deteriorate 'naturally' due to genetics (genomic/epigenomic factors), or due to external factors such as normal wear and tear, or disease? By normal wear and tear I include ...
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25 views

If hermaphrodite C. elegans can reproduce with females?

C. elegans can self fertilize, or they can mate with males. But are they able to mate with females? Or is there some kind of morphological barrier that prevents that?
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sex limited genome transmission

In general, for dioecious species, a large portion of the genome passed from parents to offspring of both sexes - in mammals the X-chromosomes and autosomes are passed from a mother to both daughters ...
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How does chromosome cross-over occur?

I have heard that during meiosis, homologous chromosomes from each parent "cross-over", which enables the off-spring to inherit some alleles from the mother and some alleles from the father. The ...
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303 views

How was the Huntington's disease gene's location found?

I read in the book "Why we get sick." by Nesse and Williams that: Steady detective work and fabulous luck have enabled geneticists to pinpoint the Huntington's gene on the short arm of ...
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86 views

Why is Turner syndrome rarer than Klinefelter syndrome?

Turner syndrome occurs in 1-1000 to 1-5000 females, and Klinefelter syndrome occurs in 1-500 to 1-1000 males. Why is Turner so rare even though they both are caused basically by the same mechanism?
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Negative value on linear gene expression in microarrays

I am starting to use microarrays and maybe this is a dumb question: Using Illumina microarrays, linear gene expression can be negative? Or maybe some artefacts have been introduced? And, in this ...