Questions tagged [genetics]
Genetics is the branch of biology that deals with the transmission and variation of inherited characteristics.
2,220
questions
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1answer
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Breeder's equation and equivalent expressions for narrow-sense heritability
I am trying to model the phenotype of a trait as $X = G + E$, where $G$ and $E$ are the genetic and environmental effects. (I'll ignore the distinction between broad-sense and narrow-sense ...
2
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0answers
65 views
What is the charge of (bacterial) ribosome?
Ribosomes are negatively charged and thus electrostaticaly repelled from DNA. However, I could not find a good reference that would allow me to estimate the magnitude of negative charge on a ribosome. ...
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0answers
31 views
Expected $\mu$ and $\sigma^2$ for a phenotypic trait, given heritability h and known parental phenotypic measures?
Say a measurable phenotypic trait has mean $\mu =0$, variance $\sigma^2 = 1$, and heritability $h$, meaning that h*100% of the variation in the population is caused by genetic variation and (1-h)*100% ...
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0answers
56 views
What is the probability that a gamete will only contain father's chromosomes
As it is depicted in most textbooks, cross-over does not occur between the two "outer" sister chromatids. By independent assortment during Meiosis I, there is 1/2^23 chance that all father's ...
0
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1answer
33 views
Could Cyanobacteria farms help dilute pollutants in the atmosphere
If I understand correctly, roughly ~2.8 billion years ago cyanobacteria started pumping large amounts of oxygen into the atmosphere.
Using modern industrial processes could this be emulated by ...
0
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1answer
136 views
Does natural selection still increase biological complexity?
I recently read The Selfish Gene by Richard Dawkins, which I found very interesting. In one of the last chapters, he gives multiple possible explanations to the question "Why did natural selection ...
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0answers
46 views
Hardy–Weinberg equilibrium for SNPs
I have a SNP stats file structure, which contains all information about genotypes and imputed SNP/INDEL imputation qualities, allele frequencies and minor allele assignment.
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3
votes
1answer
153 views
How many generations are required for a specific neutral mutation to reach fixation?
In population genetics, the term “time to fixation” is defined as the time it takes for a specific mutation to appear in a population, plus the time required for this mutation to spread throughout ...
0
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1answer
87 views
What are the disadvantages of myelin
The myelination of axons has plenty of advantages. It increases signal speed in axons, and thereby reduces reaction times. This is, of course, very good for the survival of the animal in question.
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0answers
20 views
More efficient method of calculation genotype or phenotype ratios rather than doing a trihybrid punnett square or forked-line method?
Is there any other more efficient method of predicting ratios of offspring phenotypes or genotypes than doing a trihybrid Punnett square or forked-line diagram? Or are those two methods really the ...
2
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1answer
118 views
How to calculate percentage of DNA that ancestors contributed?
In David Reich's book "Who we are and how we got here" there is a graph explaining that more we go back in our ancestors generations, the least we have chances to have any DNA inherited from one of ...
0
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0answers
43 views
Can men with Klinefelter syndrome produce chromosomally normal sperm?
Individuals with Klinefelter syndrome are XXY. Even though sperm counts are low some individuals can generate enough to be used in IVF and have offspring.
Does this mean that when sperm are formed, ...
0
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0answers
60 views
Why do individuals vary in the number of SNPs for a given gene ( e.g. FOXO3A )?
Individual #1, sequenced by 23andMe and then inputed into Promethease for SNP data has the following SNP output:
1) rs1935949(C;T)
2) rs2802292(G;T)
3) rs13217795(C;T)
4) rs13220810(C;T)
5) rs2764264(...
1
vote
1answer
42 views
lifespan of Nautilus compared to other cephalopods
Most cephalopods live uncharacteristically short lifes compared to other creatures of their size and intelligence. The octopuses with the longest lifespan for example, the giant pacific octopus, only ...
0
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2answers
93 views
Evolution of hunting behavior of parasitoid wasps
Wasps in the genus Pepsis lay their eggs in a specific region on a species of tarantula and their larvae eat the tarantula organs in a specific sequence to keep it alive as long as possible.
How ...
1
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1answer
77 views
What are the implications/predictions of the selfish gene theory?
Are there any testable predictions or implications of the selfish gene theory? Or it is just interesting interpretation of the observations/experimental data? If this theory is not falsifiable and ...
0
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0answers
30 views
Genes where both a disabling mutation and copy number amplification cause different genetic diseases
I'm trying to make a list of such genes, because they must be tightly regulated. MeCP2 is one - it causes Rett Syndrome with a disabling mutation, but causes MeCP2 duplication syndrome if its copy ...
0
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1answer
61 views
What is indirect vs direction selection of genes?
As the title suggests, what is the direct and indirect selection of genes. Couldn't find a straightforward answer. Is it the same as direct and indirect fitness?
0
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0answers
36 views
Which sample type is more proper for whole genome sequencing in AML patients? Peripheral blood or bone marrow?
I intend to perform whole genome sequencing in AML patients in order to find genomic abnormalities, particularly translocation and gene fusions. However, I am not sure whether it is better to obtain ...
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1answer
53 views
Frameshift Mutation
With regards to LMNA frameshift mutations further downstream in the tail region, specifically (p.Arg455Gln fs*5) which has yet to be found/recorded in any medical literature...Does anyone have any ...
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1answer
56 views
Can Huntington's Disease be homozygous dominant?
Can Huntington's Disease be homozygous dominant? I am not sure whether the individual who is homozygous dominant for Huntington's Disease will survive into adulthood, or die when they are infants or ...
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4answers
5k views
How do mutations of viruses lead to drug resistance?
For instance, after starting zidovudine monotherapy against HIV, resistance develops against the drug because of a point mutation in the RNA transcriptase enzyme to which the drug binds.
So how does ...
0
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1answer
42 views
Gene APOA2 SNP rs5082 alleles are A or G, but papers describe it with CC and TT?
rs5082 is a SNP in the APOA2 gene. It is associated with obesity and heart disease risk.
According to this article the alleles can be A or G
https://www.ncbi.nlm.nih.gov/snp/rs5082#frequency_tab
Why ...
2
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1answer
41 views
Quantifying the Genetic Basis of Complex Diseases
In general, there are 2 types of diseases for which we understand "causality" very well:
Infectious disease, where there is some etiological agent that causes the disease and
Monogenic genetic ...
1
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1answer
41 views
PCR markers for C57B6
Do you know any primers that can be used to genotype mice and check if they are still C57B6? I'm concerned about genetic drift in my colony. I bought a breeding pair 3 years ago and expanded. I wanna ...
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0answers
37 views
Effect of myelination on inteligence in cephalopods
Cephalopods are known for their unique intelligence compared to other invertebrates.
The number of neurons of cephalopods is of the order $5*10^8$, similar to dogs. Humans have about $10^{11}$ ...
1
vote
2answers
100 views
ELI5 what is true breeding?
In "Variation under Domestication", Darwin makes several references to the concept of true breeding:
They believe that every race which breeds true, let the distinctive characters be ever so slight,...
1
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1answer
29 views
Analysis of post transplantation lineage tags
I'm having some trouble understanding some bits of a study, mostly about the Sleeping Beauty system and TARIS model, from this paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408613/
I ...
1
vote
1answer
68 views
Are there animal species where some females have greater amounts of male-associated qualities than average males?
In the human species, some women ( a meaningful, though not large percentage) are taller and stronger than the average man.
Is a similar thing true in the animal kingdom? Are there some meaningful ...
4
votes
2answers
95 views
What is the substance that tumors release that stimulates growth of blood vessels but suppresses its release from other tumors?
I'm currently in high school and I am working on a cancer research project. My project consists of a cancer, and different ways to treat it. I have a set of benign tumor and I was thinking of ...
1
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0answers
43 views
How can we say that a gene is spacio-temporally regulated?
Gene expression is depending on the space and time of the cell. How can we distinguish the function of a gene without a chance of changing its expression? And also how is it possible to find the exact ...
5
votes
2answers
297 views
What controls specific gene silencing during cell differentiation?
I am intrigued by the fact that all cells of our body use the same DNA. How do the cells differentiate during the post fertilisation divisions?
I read about gene silencing, which can be an answer to ...
7
votes
2answers
94 views
How does a drastic change to the genome persist and spread?
I just read the article on songbirds in the November, 2019 Scientific American. The article explains that songbirds have an extra chromosome, called GRC (germ-line restricted chromosome) that other ...
9
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3answers
438 views
How Incomplete dominance can be explained at molecular level?
What is exactly happening at the molecular level when two alleles constitute incomplete dominance? Whether the protein formed from each of the alleles constitute a new protein having a different ...
0
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0answers
31 views
Study on Introns?
I am curious whether there has been a study done on the effects of removing introns. Specifically, what happens if you genetically edit a eukaryote genome to no longer contain introns? Or maybe just a ...
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votes
1answer
174 views
Genetics and Heredogram - Proving the teacher is wrong
I want serious help here. I'm in first year of medical school and I jut had my second test in Genetics. One question of the test gave us a heredogram and asked us what was the most probable type of ...
0
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0answers
28 views
Brain evolution in the age of the caesarian
I have just been reading an account of the evolution of human intelligence in Matthew Syed’s recent book on diversity, called “Rebel Minds”.
He is not the originator of this idea, but he suggests ...
1
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3answers
198 views
Is evolution a means to an end?
In "The Red Queen", Matt Ridley frequently argues that evolution is a means to an end, without providing much explanation for such a big statement.
Is this a fact in biology? Do species mutate their ...
19
votes
1answer
2k views
Do some genes follow Rock-Paper-Scissors model of dominance?
Assuming there are at least 3 alleles of the gene $G$ in total - $G_R$, $G_S$ and $G_P$ - is there any gene for which the following is true?
$G_R$ is more dominant than $G_S$.
$G_S$ is more dominant ...
-1
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1answer
64 views
Why is sickle cell trait expressed in half of all cells rather than all cells containing half-sickled haemoglobin
If sickle cell trait is due to be heterozygous with respect to a single gene mutation on the haemoglobin β-globin chain, why is it the case that ~50% of RBCs are sickled rather than half of the ...
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0answers
36 views
Which trait does the given Pedigree chart show? [closed]
I have a doubt in this pedigree chart , according to me it should be autosomal dominant. But the ans given is X linked recessive , in the case of X linked recessive one daughter should be carrier and ...
0
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0answers
68 views
How much DNA (or genes) do homo-sapiens and ursus arctos (brown bear) share?
How much DNA (or genes) do homo-sapiens and ursus arctos (brown bear) share? There are articles online that indicate that humans share xxx% of DNA with Chimpanzees, bananas, and other assorted ...
2
votes
1answer
64 views
Is every flower on a plant unique?
I've noticed on my dahlia plants that sometimes there's a flower which looks completely different then the rest . Either color or structural. I dig these bulbs up each fall and keep inside to replant....
1
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1answer
474 views
What is the genetic reason that this flower has petals of two different colors?
I have two different varieties of the flower, portulaca: one is bright pink, the other is pure white with pink specks at the centre. Recently a flower bloomed which had 50% of the former and 50% of ...
3
votes
1answer
177 views
Can primers for PCR be duplicated?
Complete beginner question here, don't laugh:
If I have some primers that have been synthesized, and I am close to running out of them, is there any way to duplicate them / amplify them / synthesize ...
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0answers
29 views
chromosome 19 and recombination
Im doing a project with structural variation created by recombination within the human genome during spermatogenesis, where im especially examining intrachromatid homolog recombination.
I find that ...
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1answer
86 views
Why does X inactivation happen?
Is X inactivation really important? Why don’t the dominant genes on one chromosome mask the recessive on the other chromosome? This happens in other sets of chromosomes so why exactly does this happen ...
0
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2answers
30 views
What's the difference between the terms “gene map” and “genome”?
It seems some sites arbitrarily restrict "gene map" to only a single chromosome, but others don't. Supposing we don't restrict it to just a single chromosome, is it different from "genome"? Are these ...
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0answers
16 views
Linkage terminology in drosophila
Consider two linked loci that are 50+ map units apart. I perform a test cross between a female that is heterozygous at both loci to a male that is homozygous recessive. In this case, the phenotypic ...
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0answers
45 views
Linker DNA and Genetic Expression
So I was reading on linker DNA, and the textbook only describes it in terms of structure. I was wondering if linker DNA can ever contain genes, and if it can, whether it will always be expressed or ...
