All Questions
Tagged with inheritance or genetics
2,516 questions
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With CRISPR-mediated gene editing, can the PAM for the guide RNA also be site of the desired edit?
I'm hoping to use CRISPR-Cas9 in yeast to change a single nucleotide in a gene of interest. While there are a couple potential guide RNA sequences I could use, the best option's PAM sequence (TGG) it ...
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75
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Patterns of craniofacial topology
There are animals which are not directly related but have similar craniofacial topology.
For example: koala, donkey, mouse, turtle, parrot all have features seemingly belonging to same topology, ...
- 109
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54
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Reading genotype aloud
For this genotype, P2ry12$^{+/+}$ I read it "P2ry12 wild type." For animals with the GFP being expressed under one Cx3cr1 promoter, Cx3cr1$^{+/GFP}$, how do I read that aloud?
What about for:...
- 303
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101
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How to resolve the contradiction between the time required for the fixation of neutral mutations and the time available according to the fossil record
More than thirty thousand synonymous single-nucleotide-substitutions have occurred in protein-coding genes in the human genome since the human lineage diverged from the chimp lineage ~7 million years ...
- 39
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28
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Why is the expected time to coalesce the same as the ploidy times inbreeding effective population size?
The expected time to coalesce, in generations, is the same as the ploidy (e.g., 2 for humans) times Nef, the inbreeding effective population size, under coalescent
theory. Why?
Both ploidy * Nef and ...
- 401
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3
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114
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Have there ever been "half-twins" who were halfway between siblings and twins?
Have there ever been two human siblings who were 75% or more genetically related?
- 401
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43
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Has perturbation theory been applied to mutation process frameworks?
For example, imagine this Feynman diagram:
This is analogous to mutational homoplasy.
When comparing haplotypes, there are many possible tree topologies. Under maximum parsimony, we ignore suboptimal ...
- 401
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55
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How exactly are the eye color genes related?
How exactly are the gey (maybe aka EYCL1?), bey(2?) (aka EYCL3?), HERC2, and OCA2 genes related to each other? There are numerous sources that explain eye color in terms of OCA2's role in the creation ...
- 111
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354
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What are the chances that two children of the same couple will have the same genes without being identical twins?
If I randomly select half the chromosomes of the male and female eventually I will select the same exact half for both a second time. How often does this occur? Is this considered a twin if it is born ...
- 1,713
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125
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How did the Zinder-Lederberg experiment on Transduction work?
In the paper that introduced TRANSDUCTION (J Bacteriol. 1952 Nov;64(5):679-699), Lederberg and his student Zinder reported that S. typhimurium
"LT-22 is lysogenic for a virus active on LT-2. ...
- 693
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83
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Bacteria genetic screen for mutants
Is there a simple screen for bacterial mutants with increased mutation rates? For example, detection of some loss-of-function mutation that causes increased mutation rates.
Any screen I can think of (...
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194
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Change of DNA concentration due to restriction digest?
Assume that you perform a restriction digest in a molecular biology lab: you combine genomic DNA, a restriction endonuclease (e.g., EcoRI), and the optimal buffer for that endonuclease and are about ...
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29
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Coefficient of fraternity between grandparent and grandchild from full-sib parents
I have the following pedigree and I would like to calculate the coefficient of fraternity between individual 1 and 5. R/AGHmatrix::Amatrix gives a coefficient of 0 for this pair. Shouldn't it be non-...
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86
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Gene Mapping - Please explain in Lay terms
Taking an AP bio course, and for some reason I cannot comprehend the mechanism of how one determines the location of alleles on a chromosome. The math is simple and I can memorize it, but its bugging ...
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48
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What software can be used for simulating human meiosis, taking linkage and recombination into account?
I want to study the nature of genetic variation in offspring from the same set of human parents. To this end, I would like to take two (male and female) complete genomes, generate gametes from them, ...
- 157
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3
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91
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Is there any objective way to describe ethnicity?
Is there any objective way to describe ethnicity that does not rely on arbitrary sociocultural concepts like referring to racial constructs, modern nations like “Spanish”, or even continents like “...
- 153
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73
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Is there a convention regarding the use of forward vs reverse DNA strand to represent DNA sequence?
I see in this paper the notation IL-1A C[-889]T which suggests that for this gene, the reference allele is C and the variant is T.
However, when I look up the same gene on dbSNP, it says the alleles ...
- 103
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288
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How to calculate df in the chi-square test of Hardy-Weinberg equilibrium? [closed]
We often use df=1 in Hardy-Weinberg equilibrium when there are only two alleles. Some people say that it's because we've used the frequency of two alleles when calculating the expectated values, while ...
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22
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Why is the maximum propotion of MII 2/3 in the ordered tetrad analysis? How is it different from normal recombination?
My textbook says that the maximum propotion of MII gametes in the ordered tetrad analysis is 2/3, and if we put it into the formula RF(recombination frequency)=MII/2(MI+MII), we can find out that the ...
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36
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Is there potential to modify GM crops to inhibit their reproduction with non-GM crops?
I've been reading on terminator gene sequences and was wondering whether the same technology could be applied to GM crops to prevent transgene flow. Turns out Monsanto had developed the technology but ...
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174
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Hardy-Weinberg Equilibrium Test Result for Merged Genotypes
I was curious if two populations are in Hardy-Weinberg Equilibrium (HWE), and if they are merged, then what happens? To find out, I considered populations from the 1000 genome project data. For ...
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56
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How frequently does recombination occur, and how long are the recombinated fragments?
I understand the mechanics of recombination, but am struggling with the 'scale'.
When two homologous chromosomes pair, roughly how many recombination events occur on average? I understand there will ...
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159
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Can a person have different sex at cellular level?
I mean like every cell has a sex chromosome.So does a male with XY chromosomes has all the cells in all the organs inside his body of XY chromosomes only? And vice versa.....
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123
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How many base codes are in DNA? Two or four?
We know there are four bases found in a DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). We also know that A always pairs with T and G always pairs with C. Can we say that the DNA is ...
- 101
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93
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Are there two different senses of the word 'heritability' in use?
Target Height as Predicted by Parental Heights in a Population-Based Study states:
The heritability value was taken as the regression coefficient between
final height and midparental height
Is this ...
- 111
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167
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Could the inability of adult mammals to digest lactose be partially explained by the loss of lactose-metabolizing bacteria from the microbiome?
BACKGROUND:
1. Lactase persistence
Lactase persistence is the continued activity of the lactase enzyme in adulthood, allowing the digestion of lactose in milk.
According to Wikipedia, only a small ...
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167
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What is the exact definition of the term 'trait'?
A trait is a characteristic shown by an organism.
For example a Tt plant would show the 'tallness' trait.
It seems to me that, by analogy, sickle cell anaemia (SCA) carriers should show the 'normal' ...
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249
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Why is the codon size three, rather than four? [duplicate]
The genetic code consists of triplets, each of which (apart from the stop codons) yields an amino acid when the mRNA is translated.
But why did triplets evolve, rather than a longer or shorter codon ...
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21
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Databases medicine and therapy - animal & human studies, technology readiness level
I am looking for some universal databases that would offer information about drugs and therapies currently in development.
The area of interest is mostly cell and gene therapy. I am looking for ...
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68
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Inheritance of child behavior based on daily life experiences of the parent
Our brain is a large network of neurons connected with each other.Our daily experiences change how our neurons are connected.Some experiences create better connections between two neurons A and B and ...
- 111
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1
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45
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How to disambiguate between chromosome and chromosome pair?
Our genetic information is stored in 23 pairs of chromosomes that vary widely in size and shape. Chromosome 1 is the largest and is over three times bigger than chromosome 22.
Source: https://www.ncbi....
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180
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Calculating pitch of B-DNA
From this question (How pitch of a DNA Helix is 3.4 nm?), I've learnt that for counting the number of axial rise for 10 base pairs in 1 helical turn to measure the pitch of B-DNA, we have to include ...
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62
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How does positional memory in fibroblast cells work?
I have a question regarding how positional memory in fibroblasts work, specifically, where the memory comes from/how its made.
For example, the Salamander & other amphibians are able to regenerate ...
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54
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What exactly is "Whole-genome sequencing"?
Newbie question: For few years I have seen news like “Whole-genome sequencing” is now under $1000 etc. I believed that this means all the base pairs of all chromatids in a single cell are identified ...
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268
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What do alleles look like visually on linear DNA strands?
I've seen many textbook images of alleles on homologous chromosomes with the gene loci identified but how could this be visualised on linear DNA sequences with the bases written out? Is it that you ...
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1
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30
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What is a good expression vector for Salmonella enterica subsp. enterica serovar typhimurium
I am interested in expressing custom proteins in a Salmonella strain, however I am facing difficulties in finding the appropriate expression vector for it. It seems that most of the resources provide ...
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1
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302
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Considering Two Genes, Are There Only Two Possible Outcomes for the Four Gametes Produced After Meiosis, Regardless of Independent Assortment?
Is it true that for a single meiotic event when considering only two genes, there are only two possible genetic outcomes among the four gametes produced, regardless of whether the two genes are found ...
- 139
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64
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Mitochondrial diseases inheritance
I've read information about mito genes inheritance but some parts are still obscure for me.
Here is the context:
Mother has a son that is affected by some mitochondrial disease and a healthy daughter. ...
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1
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49
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ddT-tailed TA cloning, and the fate of a double nicked plasmid in E. coli
In an undergraduate lab class on TA cloning, it was explained that ddNTPs are used as the substrate for terminal transferase when making the T overhangs of the vector. I was told this was to ensure ...
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340
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Why is There a Necessity for Two Rounds of Cell Division and Four Daughter Cells in Meiosis
Why does meiosis involve two rounds of cell division instead of stopping after meiosis I, where each daughter cell would have one chromosome randomly selected from each pair of homologous chromosomes? ...
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445
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How pitch of a DNA Helix is 3.4 nm?
How pitch of a DNA Helix is 3.4 nm?
In the image that I have attached, the numbers with prime represent the number of base pair and normal numbers represent the number of gap elements between two base ...
- 121
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52
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Is it possible for a non-self antigen to NOT be recognized by the body?
The amazing diversity of antigens that the body can recognize (by virtue of T and B cells that express receptors complementary to them) is truly fascinating. The explanation mooted for this is the ...
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231
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Is heritability just slope?
Is broad-sense heritability just the slope of the line that passes through the coordinates:
(1, The phenotypic correlation among monozygotic twins)
(0.5, The phenotypic correlation among dizygotic ...
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3
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387
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What is the exact definition of a "gene"?
(In this question, I'm only considering the molecular-biology notion of a gene, not the older Mendelian notion.)
Wikipedia defines a "gene" as "a sequence of nucleotides in DNA that is ...
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111
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How long does it take for a gene to be switched on or off through the process of epigenetic expression?
I understand that in our lifetime, our experiences affect the expression of our genes. Some get switched on, while others switched off. Our experiences, diet, lifestyle etc. determines this expression ...
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24
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Trying to find information about intraspecific allelic expression divergence in recombinant individuals due to changes in the cis regulatory regions
I am trying to find any research articles or resources that focus on differences in expression levels at the allelic level due to changes in cis regulatory regions in recombinant individuals. For ...
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39
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What portion of the human genome is dedicated to the developement of the fetus?
I was thinking about how we don't know the function of a large portion of DNA and I thought maybe it's because it's only used during the development of the fetus
- 157
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182
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Arguments against incest
Incest is forbidden in most countries because if there is a genetic disease in the family the child of a incestuous relationship will be at least holder of the gene of that disease. But lets say the ...
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Calculation for underlying genetic value of a phenotype given parents genetic values
What is the most accurate way to calculate a child's genetic predisposition to a phenotype, given both parents' genotypic predispositions?
Assume trait X is 50% heritable and controlled by an ...
- 401
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138
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Are mutation rates normally distributed? If not, what are they?
On average, there are 64 mutations per generation in the human genome. Is this constant, or can we expect variation in the number of mutations?
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