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

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The Semi-Conservative Model of DNA Replication: Question

My Campbell's Biology textbook contains the following diagram related to the semi-conservative model of DNA replication proposed by Watson and Crick. I have highlighted where my confusion arises in ...
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Simple Mendelian sex-linked chromosome fruit fly question

From my molecular biology textbook: When red-eyed flies (dominant) were mated with white-eyed flies (recessive), most, but not all, of the F1 progeny were red eyed. Furthermore, when the red-eyed ...
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Constant or variable number of chiasmata during recombination?

During recombination, is the number of chiasmata consistent for each gamete and are the chiasmata regions consistent within a single organism?
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Problem: What is this pattern of inheritance?

The following question was on a pretest of mine, and I'm trying to figure out the answer using what we've learned about Mendelian and non-Mendelian patterns of inheritance. I'm struggling quite a lot ...
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Why does the proportion of transposable elements vary so much across species?

Intuitively, transposable elements (TEs) are harmful as they may cause genome instability. However, some people argue that TEs are also sources of variations, especially regulatory sequences[1]. If ...
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Do only one or both pairs of homologous chromatids exchange genetic material during the process of crossing over?

To be specific: Assume chromosomes A and B are homologous. They've both replicated into A1, A2 and B1, B2 and have formed a tetrad at the equator (synapsis). Most textbooks show either A1 and B1 OR A2 ...
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What distinguishes Mendelian Inheritance from Non-Mendelian Inheritance?

I'm having some trouble determining what exactly is the difference between Mendelian inheritance and non-Mendelian inheritance. For instance, I understand that chromosomal abnormalities such as Down's ...
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368 views

Why is a heritability coefficient not an index of “how genetic” something is?

On his blog, Eric Turkheimer writes: [T]aken as a number, a unit of analysis, heritability coefficients are funny things to aggregate on such a massive level. What exactly are we supposed to ...
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119 views

What is allelic effect sizes and direction?

In a paper, Berkley, C. A., and C. Lexer. 2008. Admixture as the basis for genetic mapping. Trends in Ecology & Evolution 23:686–694, the definition of Genetic ...
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580 views

Pedigree Analysis: Problem

I'm struggling to arrive at the answer to the following question, which appeared on a pre-test of mine and which I am now using to study the material we've learned. According to this helpful video, I ...
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105 views

How the chaotropic agents help in purification of DNA molecule?

Those plants which are rich in secondary metabolites and polysaccharides DNA isolation can be done using certain chaotropic agents? can any one explain how it works?
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Are the genes for transcriptional factors close to their targets in the genome?

Transcriptional factors (activators and repressors) are proteins which regulate transcription. Being proteins, they themselves are also made from expression of certain DNA sequences/genes. For ...
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Is an egg classified based on the species inside it, or by the species that laid it?

Basically what I'm asking is if an animal of species x were to lay an egg, and the animal inside that egg happened to be the first member of a genetically new ...
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Why only human have noticeable difference in face? [duplicate]

Our facial appearance is pretty much different from each other unless we are talking about twin. Credit goes to crossing over of chromosome. But why can't we distinguish between other animals of same ...
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61 views

Chromosomomal walking

I'm having a great deal of trouble understanding chromosomal walking, especially in regards to this article: Control of male sexual behavior and sexual orientation in Drosophila by the fruitless ...
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73 views

What test to apply to detect genomic signatures of selection?

I would like to ask you for your sugestions for selecting a test to detect signatures of selection in the following mouse model: We have three groups: animals exhibiting trait A, trait B and controls....
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32 views

Inbred mice has no severe phenotype outcome?

Why does 20 generation of inbred mouse have no particular strange phenotypes, but on the contrary, when on purposely inbreed dogs or tigers for specific phenotype cause severe deformation of the bone ...
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62 views

Genotype of children conceived after stem cell transplant?

If you have sickle cell disease and have a succesful stem cell or bone marrow transplant, your blood type changes to AA. But what about your future children? Do your sperm or egg cells continue to ...
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146 views

When was the last common ancestor of pig and human?

Some religions regard pigs as unclean on the grounds that pig flesh is closest in composition to human flesh. I don't believe this for one instant, but it got me thinking, just how close is pig and ...
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43 views

Is there is difference between “homozygosity” and “homozygosis”? [closed]

Are these just two terms for the same phenomenon, i.e., the state of being homozygous? Merriam-Webster says so, but I know dictionaries sometimes miss the nuance of scientific terms. If they are ...
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91 views

What determines whether the maternal or paternal allele is expressed?

I am taking cell biology and have this question: During the process of gene expression, it is possible to express either the maternal allele or the paternal allele. When and how is the determination ...
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Do mutant alleles result from mutation of the wild type?

The allele that encodes for the most common form of a phenotype in natural population is called a wild type allele and all the rest of the alleles encoding forms other than the wild type are called ...
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40 views

Can you knockout specific receptors in an adult?

Sorry I don't have a good understanding of this topic, but I'm guessing that "receptor knockout" is related to/a part of "gene knockout"? And If I understand correctly, gene knockout is currently ...
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103 views

Do any dogs have blue iris - not just sclera? [closed]

I was looking in to the question of whether any dogs in fact have "blue eyes"... A quick search gives plenty of information on and images of dogs with blue sclera and black iris. Every "blue-eyed" ...
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Effect of sex-ratio on the effective population size

As stated on this wikipedia article, the effective population size $N_e$ when the sex ratio differs from $\frac{1}{2}$ is $$N_e = \frac{4N_mN_f}{N_m+N_f}$$ I understand the biased sex-ratio ...
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Why do humans have 46 chromosomes? [duplicate]

Humans have approximately 25000 genes. Why are these genes on 46 chromosomes? Why not 40 or 50?
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29 views

Difference Between Gene Delivery and Gene Therapy

What is the specific difference between gene delivery and gene therapy? As far as I understand, gene delivery is the first step of gene therapy, but where does gene delivery end and gene therapy ...
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Diffusion approximation to genetic drift

I am reading from the classical textbook Principles of Population Genetics, Hartl and Clark (pdf here). Introduction Let $f(p,x,t)$ denote the distribution of allele frequency $x$ at time $t$ ...
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Are fishes evolving?

As far as I know, Fishing has been one of the important occupation since early ages, and infinite number of fishes have already been captured. As the time passes, they must've developed some sort of ...
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How many genes does D. melanogaster have?

Obviously there is no 100% exact number, but I came across this on flybase, the gold standard for annotation. I am confused now. "Genes located to the genome", is that what I am looking for? If so, ...
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“Signal Advance”: Unsure of meaning or contextual use

I am reading through Recombinant DNA; Genes and Genomes - A Short Course - Third Edition by James D. Watson, et. al. and I came across this paragraph in the discussion about discrete factors of ...
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52 views

Is it possible to have raw ngs data to practice

I'm looking for raw human ngs data to practice in bioinformatics. Better if it is from different machines (illumina, roche, pacsbio, etc). Panels, exomes and genomes. Anyone knows something?
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138 views

Can an argument be made that humans are 90% bacterial?

On the blog, All about Scientist in Microword: Microbiology, I read the post We are 90% bacteria, actually, which says that humans are 90% bacterial cells. If this is the case, then why don't we ...
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Colorblindness in females and random X chromosome inactivation

From Annenberg Learner: Because the X is inactivated randomly in cells, one cell could have the maternal X inactivated, while the adjacent cell could have the paternal X inactivated. This causes ...
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What is the Genetic Cause of Homosexuality? [duplicate]

So, I'm just wondering about this because I read the following in my Biology textbook about fruit fly genes: "Normal male and female flies express distinct forms of the fru gene. When females are ...
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HIV and open reading frames

In Wilk et al. 2001 I saw that HIV has 3 open reading frames. In the Watts et al. 2009, I noticed they mentioned HIV has 9 open reading frames. I don't understand this very well. e.g. ...
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273 views

What is the difference between a bacterial artificial chromosome (BAC) and a plasmid?

Is it just that a BAC is generally larger and artificially constructed? Or are there any other differences?
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493 views

What does it mean to have a Y-DNA Haplogroup “R-M512”? [closed]

I did a DNA test to learn about my origins, but the results are highly technical. I see I have a Y-DNA Haplogroup R-M512 and a mutation (zero marker in DYS448). I Googled these terms and came across ...
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123 views

What does it mean to clone a gene?

When I look up information related to the identification of disease genes, texts will often refer to the gene being "first cloned." What does "clone" mean in this context? Is it simply a synonym for ...
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51 views

Sexual selection and genotypes [closed]

I have question about genetics and sexual selection. This is re-worded from a problem that was posed to help me and others understand what is going on here. Say you have a fictional species on an ...
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29 views

Why are we supposed as unable to change our intrinsic behaviour? [closed]

People say that habit can be changed but not the intrinsic behavior of an individual. One can control it for a certain period but eternal control or refrain is not possible. Is that true? If yes why?
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Math backbone in biology/genetic

Are there any good books, that shows some advanced models in genetics particularly? The problem is i don't see any good math model in genetics interactions exept combinatorics. I'd like to know what ...
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Amputation of part of the cytoplasm of the amoeba? [closed]

We ampute a part of the cytoplasm of the amoeba many times and we observe that amoeba is not divided This experience allows to deduce the cause of the division of amoeba Do that have relation with ...
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genetic complementation problem

I've attached the picture of the problem. SO, based on the information I managed to assemble two large cistrons. (if the combination of two mutants yield (-) mutations are on the same chromosome) A)...
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Gemini usage of --sample-filter

I am using gemini to query databases made from vcf files, which contain data from multiple samples. However, I need to query data only from one sample, (for which I currently use grep to filter the ...
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842 views

What is the instructional language of DNA?

DNA carries most of the genetic instructions used in the development, functioning and reproduction of all known living organisms and many viruses (Wikipedia). Is it already know how ATCG's sequences ...
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Difference between micro RNA and short-interfering RNA and CRISPR Cas 9 system?

I read this article https://www.quantamagazine.org/20150206-crispr-dna-editor-bacteria/ and am slightly puzzled as to why the CRISPR/Cas 9 system is seen as being so revolutionary. It seems like the ...
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Gel Electrophoresis

we add Etbr within the agarose gel but we do not add Etbr directly in native PAGE ?when we make agarose gel, we add Etbr before its solidification but we do not add Etbr when the native PAGE gel is in ...
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Are gametes determined by the sex of an organism?

In the Wikipedia article for biological sex, I read the following sentence. "The gametes produced by an organism are determined by its sex:..." However, is it not through the gametes produced by ...
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Fur genetics - what are the causes of fur colour decision?

This Australian Shepherd puppy's father is a black-tri; mother is a blue merle. What would cause this dog to have so much white color? Are there any general explanations as to why this might ...