All Questions
Tagged with genetics molecular-genetics
253 questions
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How to determine a gene based on the biological function of an organism?
I am studying genetic engineering.
I have a problem understanding how to find the necessary genes responsible for certain phenotypic traits.
Let's say plants have red petals. What methods are used to ...
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1
vote
0
answers
77
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How to test whether correlation of couples phenotypes is due to assortative mating or environment?
A few phenotypes are easier to pinpoint as assortative mating (height for example), But other phenotypes such as vitamin D, weight, etc could be a combination of shared environment and assortative ...
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0
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0
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22
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What backbone to use for Helper dependent adenovirus (HDAd)
I have been trying to design a plasmid for a helper dependent adenovirus but while looking i wasn't able to see a backbone specifically for HDAds so I was wondering if a general adenovirus backbone ...
1
vote
2
answers
47
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Preserving a sample for mtDNA and nuclear DNA analysis
Imagine a person in the early half of the 20th century (1900 to 1950) took some kind of sample(s) from a living human body using any technology of the era. They then stored it using any technology ...
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0
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24
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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 ...
0
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0
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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
answers
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?
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1
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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 ...
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2
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0
answers
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 ...
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2
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3
answers
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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1
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1
answer
213
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How random is genetic recombination?
Two parents can have a very large number of different potential offsprings, and it's common knowledge that the daughter chromosomes in meiosis are produced randomly, i.e. in crossover, the exact spots ...
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6
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1
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172
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What are the relative frequencies of dominance and codominance in genes underlying phenotypic characters?
Many questions already exist regarding dominance/recessive relationships, see e.g. here. I am asking this question because I have often wished to have it to refer to, and also genuinely curious ...
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5
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92
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Is there a name for this type of diagram?
Is there any commonly used name for this type of diagram / symbology? I have not been able to find them referred to by any name.
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12
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1
answer
2k
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How did Mendel know if a plant was a homozygous tall (TT), or a heterozygous tall (Tt)?
I had some issues while studying Mendel’s rules of inheritance.
How did Mendel, while running his test crosses, know if the plants in his F0 generation were TT (homozygous tall) or Tt (heterozygous ...
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2
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1
answer
43
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Receptors and their distribution over the human population
For humans it has been reported that there are three vasopressin receptors (AVPR1a) and four dopamine receptors (DRD2). (Source: UNIPROT)
Question: Does every human contain all three variants of ...
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1
answer
76
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When do retinal cells stop differentiating? [closed]
I am having a hard time recalling where I had heard this, but I do recall someone saying (perhaps in a video) that cells in the retina divide very rapidly during infancy due to ongoing development of ...
0
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2
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168
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Is retinoblastoma truly an autosomal dominant condition?
I am getting, in my opinion, very conflicting information from sources about the inheritance of retinoblastoma, a type of cancer. Hereditary retinoblastoma is associated with defects in the gene ...
2
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0
answers
53
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What forms a mutation hotspot?
From https://en.wikipedia.org/wiki/Recombination_hotspot#:~:text=Recombination%20hotspots%20are%20regions%20in,that%20of%20the%20surrounding%20region.
I understand that hotspots may arise when certain ...
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3
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1
answer
100
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How is a haploblock defined with only one SNP location?
I am reading Impact of estrogen receptor gene polymorphisms and mRNA levels on obesity and lipolysis – a cohort study and am looking at Figure 1. I understand that haplotypes are associated with ...
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0
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0
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37
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Biology (DNA electrophoresis with agarose)X
I'm researching a polymorphism using restriction fragment length polymorphism (RFLP) and gel electrophoresis.
After RFLP, I should see fragments at 141bp and 111bp, but I can not see in 2% agarose, ...
2
votes
0
answers
57
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Apparant inconsistency in DNA topology theory in formation of origin of replication [duplicate]
I'm studying an introductory course in genetics and came across something I don't fully understand. I obviously used Google to find where I'm thinking wrong, but I still can't understand it.
To ...
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3
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1
answer
125
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How can SNP arrays be used to detect deletions within a gene?
I am reading a journal paper where the researchers are studying the effect of disease-causing mutations in the IL1RAPL1 gene. In the first figure of this paper, they show pedigrees of families where ...
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1
vote
1
answer
59
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What is the importance of radiation hybrid (RH) mapping in terms of genes?
I'm currently reading about radiation hybrid mapping with a TSP (traveling salesman problem) application in order to find an ordering of the genetic markers (i'm a mathematics student) and was ...
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0
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2
answers
81
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How many people need to have the same mutation of a gene in order for that gene to be seen as a feasible candidate for a disease?
I am learning about genome-wide association studies (GWAS) and I know that they are used to see whether certain SNPs are associated with a disease of interest. From everything that I have watched and ...
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7
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2
answers
1k
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How do geneticists determine if a gene mutation is pathogenic?
I am analysing information about patients with neurodevelopmental disorders using the DECIPHER genomics database. I am looking for patients who have only a specific gene deleted and no other mutations ...
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4
votes
1
answer
204
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What does the 'y' mean in CHL1−/− / L1−/y double mutant mice?
I am reading a journal paper and I have come across the following statement:
To investigate this, $CHL1^{−/−}$ / $L1^{−/y}$ double mutant mice were generated
and analyzed for thalamocortical axon ...
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0
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1
answer
245
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Why is the genetic code so heavily conserved?
Except some organisms, most organisms follow the same Genetic Code
tRNAs, tRNA synthetases, ribosomes, etc. comprise the translational machinery for converting nucleotide codons to proteins.
My ...
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2
votes
2
answers
811
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What is the difference between Haploinsufficient and Autosomal Dominant mutations
I have been reading a paper that classifies genes in different groups by the type of disease-causing mutations. The categories of mutations (alleles) it gives are:
Haploinsufficient
Autosomal ...
2
votes
1
answer
56
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How many MAOA alleles are there?
The question is about the human gene MAOA.
I've seen MAOA-H and MAOA-L mentioned in papers.
The page https://www.ensembl.org/Homo_sapiens/Gene/Summary?db=core;g=ENSG00000189221;r=X:43654907-43746824 ...
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1
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0
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44
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homologous recombination and non-homologous recombination ratio during S-phase
Can I assume that it is easier to do targeted gene knock-in in rapidly dividing cells because they should have a short period of G1? Is there an easy way to measure the relative amounts of homologous ...
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0
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0
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299
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Why do chromosome pairs have different shapes and sizes?
When I look at microscopic images of human chromosome pairs I see that they have different shapes and sizes.
Is there a deeper biological reason for that? Is there some evolutionary pressure for them ...
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7
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0
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86
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What are the additional considerations for primer design in ancient DNA?
I'm familiar with the principles of primer design and have previously designed primers for use in modern DNA. However, in my current project I am working with ancient DNA (nuclear gene) and need to ...
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2
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0
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43
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Can chain-linked genetic segment data be used to reliably assign unknown relatives to either the donor's mother or father?
I am analyzing DNA matching segment data, and I am trying to broadly group all DNA matches by my donor's parents.
Based on documented evidence, I can confidently identify "Person 'B'" as a ...
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0
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37
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How do we know genes that are considered endogenous retroviruses are actually endogenous retroviruses and not just ordinary genes?
What makes these genes different as to be classed as an endogenous retrovirus? I've read the entirity of Wikipedia on retroviruses and didn't find the answer. I think it could be that these genes are ...
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2
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129
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What book teaches you about endogenous retroviruses [closed]
I'm interest in ERVs as evidence for evolution and want to learn more about them.
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1
answer
57
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Is there any way to identify if chromosomes are inherited from the same parent?
I'm a PhD student in bioinformatics working on genomic data, and I was wondering:
If I have access to a person's chromosomes, is there an assay that can determine that two chromosomes come from the ...
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1
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0
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76
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Can Monsanto's (in)famous hybrid seed crops be cloned/grafted? If not, is there a technical or legal reason?
I understand that the seeds of a crop made from modern-day super hybrids will not, usually, produce the same quality plants in the next generation. Therefore, farmers have to buy new hybrid seeds each ...
- 557
5
votes
1
answer
352
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Genomic library preparation: Why does the restriction enzyme not cut into the gene?
I am currently trying to understand creating a genomic library more profoundly. In most textbooks I read (as well as wikipedia), they mentioned that the genomic library is created by isolating the DNA ...
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1
vote
1
answer
96
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Is CRISPR being utilized when scientists use the CRISPR/Cas9 system to edit genes?
"CRISPR" and "Cas9" are different things. When a virus attacks a bacteria, the bacteria stores the viral code of the virus in CRISPR. And when the virus attacks again the Cas9 ...
- 503
0
votes
1
answer
85
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Why are almost all inborn errors of metabolism autosomal recessive? [closed]
Technically, the only inborn error of metabolism I know that is autosomal dominant is acute intermittent porphyria. Also, the only inborn of metabolism I know that is X-linked recessive is Lesch-Nyhan ...
1
vote
1
answer
32
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Can a cell receive multiple copies of an insert when using different MOIs?
I want to transduce a cell line with virus that carries a specific insert.
When using different Multiplicity of Infection (MOI), I expect to get different percentage of transduced cells, but is it ...
- 237
0
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0
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24
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What are the effect of radioactivity on grey wolves in Chernobyl?
I am doing some research about the effects that radioactivity has and is having on grey wolves in Chernobyl and more particularly on their genetics, but maybe also looking at the populations in the ...
0
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0
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55
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Questions regarding transformation in bacterial cells
First off, in transformation the donor DNA aligns itself with the complementary bases in the recipient DNA.
Now a "perfect" alignment of the donor DNA ( Sorry if my terminologies are ...
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1
answer
92
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Should I consider one or two DNA chains to find how many nucleotides are in a gene?
I am trying to solve an exercise.
How many nucleotides does a gene contain if information about 287 amino acids is encoded in it? What is the molecular mass and length of this gene?
AFAIK, I have to ...
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5
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2
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2k
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Why is a solution of cesium chloride used in Meselson & Stahl's DNA replication experiment?
Centrifugation involves separating particles of different sizes, masses, density and etc.
In the experiment, the DNA macromolecules are suspended in a solution of cesium chloride gradient and then ...
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1
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348
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Clarifying distinction between genetic recombination , translocation. and transposition
Having thought about the distinciton between these terms I have come up with the following definitions, are these correct?
Translocation describes the relocation of a chromosomal segment to a ...
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0
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0
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20
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Estimate mutation rate in UVC treated cells
I am wondering how to get a coarse estimate of the number of mutation I obtain doing UVC treatment on eukaryotic cells (microalgae) starting from information such as the survival rate, genome size, ...
6
votes
1
answer
149
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Why are Chromosome Territories important?
Chromosomes occupy discrete regions of the nucleus, referred to as 'Chromosome Territories'. This spatial organization is emerging as a crucial aspect of gene regulation and genome stability in health ...
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1
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3
answers
3k
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Evolution: Can the genotype frequencies change, but the allele frequencies remain constant?
If a population isn't evolving because it's in Hardy-Weinberg (HW) equilibrium, then I know that both genotype and allele frequencies must stay constant.
My question is, can evolution still not occur ...
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1
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1
answer
49
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Different Mutations Leading to Same Allele?
Can different mutations lead to the same allele? In my genetics books, I always see alleles referenced as, eg. Aa where A = dominant and a = recessive, but are these strictly binary phenotypes? Since ...
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