Genetics is the branch of biology that deals with the transmission and variation of inherited characteristics, particularly chromosomes and DNA.
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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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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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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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55 views
What is the minimum population size that Hardy-Weinberg calculations can be applied to?
I'm trying to find out if a particular allele is in Hardy-Weinberg disequilibrium, but the data is poor. What's the minimum population number that you can use to get any sort of respectable ...
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476 views
What are the advantages and disadvantages of using beta-galactosidase compared to luciferase as a reporter gene?
In the University labs, we have used Beta-galactosidase as a reporter gene to quantify the expression initiated by the stress-response promoter in yeast. This was done by exposing one of the two ...
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272 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's in a Name: Statistical Genetics
The novice often performs population calculations using
what is referred to as Mendelian Genetics. Soon after the
publication of Mendel's results; Hardy and Weinberg presented
their results after the ...
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130 views
What is the biological mechanism underlying caffeine intolerance? (CYP1A2 or other?)
As far as I can tell, caffeine metabolism occurs primarily via the CYP1A2 enzyme. I am curious as to whether mutations in the CYP1A2 gene are associated with caffeine intolerance. Some site that is ...
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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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64 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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556 views
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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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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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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Phenotypic Variation of cattle - looking for academic sources
Can someone please point me in the direction of a good academic article on the following:
What are possible sources of phenotypic variation of different 400 day weights of cattle?
Furthermore how ...
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165 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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52 views
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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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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2answers
186 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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3answers
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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 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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1answer
64 views
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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3answers
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Is DNA mutation locally energetically stabilizing the DNA molecule
I am no biologist, but as a physicist, a spontaneous mutation (seen as a chemical transformation) should lower the energy of the system, at least locally. So I wonder if any research has been done ...
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1answer
52 views
Precursor miRNA and a mature miRNA
What is the main difference between a precursor miRNA and a mature miRNA?
It is often the case that we have more than one precursor miRNA but only one mature miRNA. The miRNA-seq data contains only ...
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2answers
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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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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 they ...
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3answers
118 views
Can extinct animals be cloned?
Scientists have found mammoth blood, and are planning to clone a mammoth.
How does one go from having its blood to a full blown living mammoth? Is it possible?
Why does it matter if the blood is ...
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What is an epistasis group?
I have been trying to wrap my head around the concept of epistasis for a couple of days now, and I think I understand it, at least at a basic level, but I still don't understand some of the ways that ...
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What accounts for size variation in breeds of dogs?
My assumption is that dogs vary so much in size because of artificial selection pressures coming from human breeders, but are there genetic loci that roughly determine approximate size? Do other ...
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What factors govern the variable age of onset in Huntington's Disease?
"Huntington's disease (HD) is a neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and psychiatric problems." As we all know, this genetic disease ...
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153 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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75 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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1answer
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Mutation in axillary buds of trees overcoming self-incompatability?
I seem to recall from either reading or lecture that there have been instances of trees that are self-incompatible accumulating enough mutations in an axillary bud that the resulting branch was able ...
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1answer
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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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Predictable microchimerism
I read in New Scientist recently that microchimerism occurs between previously born siblings and grandparents, not just the mother.
Do we know which parts of the genome are likely to be transferred? ...
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What do breeders call the effect when a breed resists modification?
It is impossible to breed a blue rose or a cat with a bulldog shape. This is because breeding is limited by gene variations in the population.
What do breeders call this effect?
UPDATE
I guess ...
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What are treatable foetal conditions during pregnancy?
What are different foetal conditions during pregnancy that could be treated with appropriate prenatal genetic testing?
I only know that pregnant women are encouraged to take certain supplements to ...
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Predicting progeny of recessive mutations using recombination
I was asked this question on a test and got it wrong, but I'd like to know how to do it. The answers are shown in the blanks below:
You are studying two recessive mutations in the fruit fly D.
...
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Pedigree Probability of Autosomal Recessive Trait
Here is a pedigree:
The trait is autosomal recessive.
The question is: What is the probability that the bottom 2 people (4 and 5) have a child with the trait?
I tried doing ...
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What are polytene bands, and why are they there?
Drosophila polytene chromosomes have been particularly useful in genetic research, as it made cytogenetic gene mapping possible with very little effort. This was primarily accomplished due to polytene ...
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Terminology question: the scope of an allele in an organism
Let us consider a gene FOO with novel type foo.
If I were discussing an organism that has inherited foo in every cell during classical zygote formation, then I would ordinarily just say that the ...
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How does a plant decide when to grow a branch?
As a plant grows, at some point the first branch forms. As it continues, branches grow new branches, and so on, in a seemingly random way. Is it random, or is it driven by the environment (heat or ...
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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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Is there a gene that starts meiosis 2?
Yesterday I thought about a question and asked it to my friend. The question was
which gene is completely the same for a male cell that made meiosis 1 recently.
My answer was the gene that starts ...
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3answers
363 views
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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3answers
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Why don't flies avoid the motorway?
Flies have a short lifespan, therefore evolution should technically happen over a shorter period of time (years).
Flies die all the time from getting hit by cars on the motorway.
Those flies that ...
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2answers
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Gametes of two different species
I always wondered why gametes from two different species dont fuse together to form an offspring. eg a donkey (sperm) and a female dog (egg)
I know this is not possible but I'm just curious.
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4answers
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Are there more descriptive ways of naming genes and gene interactions?
I couldn't help but notice just how non-descriptive the gene names that modern genetics is using. Currently I'm reading "The new science of Evo Devo" by Sean B. Carroll and here are some examples of ...
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Evolution after the development of sexual reproduction
My understanding of evolution is that genetic mutation occurs in individual members of a species, and they become a new species.
Isn't a definition of species a group of genetically similar organisms ...
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Prenatal Marketing
This is for a short story idea.
Is it possible to modify the DNA of a child to make their metabolism more susceptible (physical response, addiction, etc) to a certain type of chemical i.e. a chemical ...
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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?
