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

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Are there eukaryotes without introns?

This question on the function of introns in eukaryotic genes made me think: I know that more basal organisms have smaller introns and fewer alternatively spliced exons compared to mammals. But are ...
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What is the inbreeding coefficient for the female offspring of a sib-mating in a haplodiploid system?

The inbreeding coefficient of a sibling mating for a diploid organism is 0.25 (each allele has a 25% of being identical by descent in the offspring). In haplodiploid organisms, males result from ...
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Is the theory of evolution being disproved by bats?

For some species the Darwin's theory evolution makes perfect sense. I can easily imagine how, for example, the giraffe has evolved to its current appearance: the natural selection was favoring ...
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How to create a collection of anonymous sequences for teaching and testing? [closed]

I am looking for a large collection (>1000) of sequence files (eg. FASTA) from any real organism or a tool to create such a collection. The sequence files would be used for teaching and for testing ...
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357 views

What phenotypes can arise from gender-related aneuploidy?

Humans normally have 46 chromosomes (two copies - one from each parent - of each of the 24 chromosomes: [1:22] + [XX or XY]). Aneuploidy is an abnormal number of chromosomes - Down's syndromes is an ...
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247 views

Hershey and Chase experiment

http://www.youtube.com/watch?v=3QJ4CjFsflA This is a link to Hershey and Chase experiment. According to this experiment, we conclude that DNA is the genetic material. But how do we conclude that DNA ...
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81 views

How do proteins and genes participate in learning?

I am a computer scientist that studies biology and bioinformatics. In the last weeks, I have been trying to study new research directions, and I would like to deepen my knowledge on the role and ...
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776 views

Are Asians more genetically homogenous than other races?

I've heard that Asians (I'm not entirely sure which subgroup was being referred to) tend to be more genetically homogenous than other races, with people of African lineage being on the other end of ...
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Why do ladybugs have a different number of points on their backs

Everytime I see a ladybug I ask myself this question. Why does every ladybug have a different amount of points on its back? Is it because of its age? Or because of its genes? Is it inheritable?
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327 views

Genetic engineering for insulin production

In order to put human DNA inside a bacteria in order to have it create Insulin, from what type of cell would you need to take the gene for insulin? I thought it should be from any somatic cell, since ...
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72 views

How are there multiple varieties of the potato?

The potato appears to propagate by growing an 'eye'/'bud' which eventually grows into a new plant. So there would probably be single representative of the potato species in the world with all others ...
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126 views

What exactly is meant by the expression “differentially expressed”?

As far as I've seen, this expression is almost always used in relation to gene expression profiling. Unfortunately, I have no background in this area. Can someone please explain this in layman terms?
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502 views

How do I calculate the change in allele frequency in a haploid population under selection?

From this book For simplicity, let us consider a haploid organism and assume that the frequencies of alleles $A_1$ and $A_2$ are given by $x$ and $y=1-x$, respectively. We also assume that the ...
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235 views

Double mutant analysis with null mutants

My professor was talking about double mutant analysis with null mutants, and how double mutant analysis won't work with hypomorphs. I really don't understand the concept of double mutant analysis. ...
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144 views

Results of a complete DNA sequencing - are they 100% reusable?

Is that correct that a complete DNA sequencing (the whole genome) need only to be done once (per person)? After that is done, it the complete genome can be stored and once the new genes (and their ...
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795 views

Chromosome 2 fusion?

I read this article by Jeffrey Tomkins and Jerry Bergman claiming to debunk chromosome 2 fusion. Is there anything wrong with these conclusions? " 1.The reputed fusion site is located in a ...
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102 views

A photosynthesizing mouse?

N. Shubin's Your Inner Fish makes the point several times that there is a lot of functional similarity between some seemingly remote gene cousins. If that needed reinforcing we have the spider-goat, ...
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194 views

Why does the slope of parent-offspring regression equals the heritability in the narrow sense?

Background ---- Notations and assumptions ---- let $W_{ij}$ be the fitness associated to the genotype $AiAj$. $x$ is the frequency of the allele $A1$ in the population. The frequency of the allele ...
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128 views

How do mutations come to be shared by all cells?

It's my understanding that various hazards can damage the DNA in our cells, causing mutations. But whenever I picture this, I see the damage being done to one of our tissues (for example, our lungs ...
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66 views

Drosophila reference genome

Does anyone know the details about which line they are using to sequence as the Drosophila melanogaster reference genome?
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62 views

Influence of temperature on transcription, protein binding and decay rates

I am the kind of biologist who doesn't know much about molecular genetics and about the dynamic of biochemical reactions. Question My question concerns the influence of temperature on the dynamic of ...
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103 views

Collective name for the X- and Z-chromosomes

Chromosomes are grouped as sex chromosomes or autosomes, with the X, Y, Z and W all falling in to the former category. The Z and X are present both in the homogametic and heterogametic sexes, and the ...
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259 views

Fisher's Fundamental Theorem of Natural Selection

Ronald Fisher discovered what he, with humility, called the Fundamental Theorem of Natural Selection. This theorem says (in its modern terminology): The rate of increase in the mean fitness of any ...
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371 views

Causes of monozygotic twins

Twins could be monzygotic i.e. identical twins and dizygotic i.e. non-identical twins.Well, monozygotic twins occur when a single egg is fertilized to form a zygote which later divide into separate ...
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How does the colinearity of the HOX genes determine the body plan of an organism?

I was recently reading about colinearity in the HOX genes that give an organism its high-level body plan (where the order of the HOX genes on the chromosome follow the head-to-tail order of body ...
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152 views

Inheritance of Huntington's disease

People with Huntington's disease have HTT genes with more than 37 copies of CAG repeat. The risk of extra copies being generated is higher during sperm formation than during ovum formation. Why is it ...
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71 views

Transcriptionally-mediated DNA damage

I'm researching the genetics of brain cancer, and finding a huge number of mutations in voltage-gated channels. It stands to reason that some of this DNA damage is due to the DNA being transcribed ...
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41 views

Definition of “structural underdominance”?

In Stathos and Fishman (2014), the authors refer to the concept of structural underdominance. The first time they mention it is in the first paragraph of the second page (left column) and the term is ...
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71 views

Epistasis Involving Multiple Loci

The following problem is from Schaum's Outlines on Genetics, 5th edition, by Elrod and Stansfield. I'm having some trouble solving it. It is found under a section entitled "Interactions with Three ...
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137 views

Sexual Differentiation in Monoecious plants with unisexual flowers

In monoecious plants having unisexual flowers (eg Zea Mays, Ricinus Communis etc), there must be some mechanism as to produce two sexually distinct flowers from the same genotype. Since both the type ...
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151 views

How does a tiger have stripes?

A vague question, but let me try to explain. My friend explained to me that in females, some cells use one X chromosome, while all others use the other X chromosome. This can result in some ...
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137 views

How does sex differentiation work in Paracerceis sculpta, the sexually tetramorphic isopod?

Paracerceis sculpta is a marine isopod species known for its unusual reproductive strategy: female: medium-sized; lives in harems run by an α male α male: large; keeps a harem of females β male: ...
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1k views

What is a focal copy number variation?

Often, genetics studies, especially genome wide ones, talk about "focal copy number variations" in genes or regions of the chromosome. I know what a copy number variation is. What does "focal" mean, ...
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What is 'independent assortment'?

What is the definition of 'independent assortment'. I tried researching this term but came back with two results: alleles assort themselves independently of different alleles the alignment of ...
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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 ...
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70 views

Are all functions of a human cell known? [closed]

Please bear with me as I'm intruding into your world from a computer science background. In programming, once you have created a program, you know all functions of that program. Thus, 100% knowledge ...
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133 views

How do you merge SNP data with a reference genome?

My Data I have a 23andMe file listing SNPs in the form: ...
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117 views

Does conjugation support gene selection?

I have already posted this on chat but haven't got any response. A recent question on group selection stimulated me to ask this here. QUESTIONS: Why should bacteria conjugate? If we consider that a ...
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148 views

Microarray data and analysis tools

Microarray has various uses, and to analyse the data a main function classification is used. There are many methods used to classify the data but what are the best and most frequently used methods? ...
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Difference between mutation and DNA damage

What is the strict difference between mutation and DNA damage? As far as I understand it, a mutation is an alteration in the genetic sequence, having "tricked" the repairing machinery and thus ...
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137 views

How do the variable portions of antibody genes look in cells which don't produce antibodies?

There are several families of antibodies found in mammals. They may have two or more antibody domains which contain heavy and light chains. The variable regions of the light and heavy chains genes ...
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139 views

Non-monotonic knock-out effects in prokaryotes

Typically, when performing gene-knockout, the experimenters select one gene to remove/replace-with-junk and then see if the prokaryote can still undergo fission. If it continues to reproduce then the ...
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96 views

Online toolkit that provides functional similarity scores (in the form of a matrix) between two functional gene sets in the context of gene ontology

Where can I find an online toolkit that provides functional similarity scores (in the form of a matrix) between two functional gene sets in the context of gene ontology? I have tried the following: ...
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Co-transformation of plasmids from the same incompatibility group

Can two plasmids with the same origin of replication (for example pBR322 ori) and thus from the same incompatibility group be successfully co-transformed in E. coli? What are the mechanisms that would ...
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79 views

Will genetically modified food affect our health?

It's a popular public sentiment that - GM foods like tomatoes (flavr savr) will affect our health.. Is there any logical scientific explanation behind this?
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43 views

Is there an association between environmental and mutational robustness?

The robustness of a genotype is the ability of this genotype to resist (always produce the same phenotype) to various parameters such as mutations and environment. The ability of a genotype to resist ...
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51 views

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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88 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 ...