Questions tagged [genetics]

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

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Why would lethal genes evolve?

I've been reading through 'The Selfish Gene' by Dawkins. At a few places in the book he states that incest is damaging because it would give a very high chance of lethal recessive genes becoming ...
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Why do people with type O blood have anti-A and anti-B antibodies?

People with type O blood have anti-A and anti-B antibodies, even without receiving a transfusion. Why?
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Altering the human genome

I recently had a conversation with a rather unusual gentleman who was, let's say, more than a little partial to conspiracy theories. He has this idea that governments are lowering "nanowires" from ...
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Why pick just a single bacterial transformed colony

So after bacteria have been transformed to perhaps grow up a plasmid of interest, why pick only a single bacterial colony from a selective plate for further expansion? I understand that this is to ...
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Are alleles equally sized?

If alleles occur at the same locus on a chromosome, does that mean they are of the same size? I was under the impression that they were, but I saw a gel electrophoresis testing different alleles of ...
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How close genetically is the most human-like chimpanzee to the most chimp-like human?

I understand that: Chimpanzees are the closest species to humans genetically. Only 1%-6% of their genes are different. Within any species there is genetic diversity, i.e. no two individuals have the ...
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How is genetic speciation defined?

What determines speciation at a molecular level? At what point does a scientist determine two lineages are different enough to be considered separate species? Does it have a margin of error?
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Is there a genomic code for nucleosome positioning?

What does a genomic code for nucleosome positioning in eukaryotes actually mean? By the code is it right to think that specific DNA sequences favour nucleosomes and others don't? I see that there for ...
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Are STOP codons impacted by base insertion or deletion mutation?

I am learning about base insertion and deletion mutations. An example in my textbook is given below. GUU CCA CAU AUC. So if there is an insertion (of guanine): GUU GCC ACA UAU C_ _ (there will be a ...
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Do the eggs for larger litters come from the same meiosis events, or different ones?

There are some species of animals that give birth to more than one pup at a time. In these species, are the fertilized eggs all from one or a limited group of meiosis processes, or are they from ...
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Redundancy of the genetic code

One particular codon codes only for one amino acid, but an amino acid can be coded for by several different codons. Now according to the genetic code, the codon UUU ...
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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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Does the word “polymorphism” refer to the gene, the phenotype, or both?

In genetics, does the word "polymorphism" properly refer to genes, to phenotypes, or both? For example, if there are two alleles that lead to differences in the structure of the D2 neuroreceptor, ...
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Is it possible to trace of the ancestry of a person by only using his/her genetic information?

Is it possible to trace the descent of a person only using his/her genome sequence?
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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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How is it possible for only one in five children to have brown eyes when their parents both have brown eyes?

I have observed that parents having brown eyes had three female offspring with blue eyes, one son with green eyes, while only the youngest daughter had brown eyes. How can they produce so many blue-...
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What causes XYY Syndrome?

It's obvious how a misdisjunction can result in klinefelter's syndrome (XXY) but I don't see how this can result in XYY syndrome. Your parents have a collective total of only one Y chromosome so how ...
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Gene & Protein nomenclature: N-Myc, c-Myc, et. al

Can someone explain (or point me to an explanation of) exactly what is meant by all the different symbols I see used for writing genes and proteins? I think I know that for genes, we use an italic ...
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Examples of environmentally influenced gene-expression in humans?

In discussions of the relevant importance of genetic and environmental influences on the development of the individual, it's often stated that the genetic and environmental influences interact. An ...
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How does the colinearity of the HOX genes determine the body plan of an organism?

I was recently reading about colinearity in the HOX genes that give an organism its high-level body plan (where the order of the HOX genes on the chromosome follow the head-to-tail order of body ...
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Why can't we breed watermelons without any remaining seeds in the flesh?

Watermelon is just starting to come in season in the northeastern U.S., and having a seedless watermelon is convenient. The only downside is, the "seedless" almost always still have the immature, ...
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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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Why do we still have genetic disorders that show anticipation?

Anticipation whereby symptoms of genetic disorders occur earlier and with more severity as it is passed from one generation to the next. So wouldn't these inherited diseases over a few hundred ...
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How often does bacterial transformation happen?

I have been reading: M. Dröge, A. Pühler, W. Selbitschka, "Horizontal gene transfer among bacteria in terrestrial and aquatic habitats as assessed by microcosm and field studies", Biol. Fertil. ...
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Fisher's Geometric Model for Dummies

Fisher's geometric model is still today one of the most important and fundamental model in evolutionary biology but it seems to me that most student in evolutionary biology don't really understand it (...
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Difference between mutation and DNA damage

What is the strict difference between mutation and DNA damage? As far as I understand it, a mutation is an alteration in the genetic sequence, having "tricked" the repairing machinery and thus ...
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What is the difference between copy number changes with and without allelic imbalance?

I require some clarification on copy number aberrations (structural gain and loss in chromosomes). From what I understand, gain/loss per se can be divided into two types. Consider two alleles, A and ...
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What determines the colors and patterns of a clam shell?

Earlier this week I was looking at some bivalve shells that had ornate patterns which ranged in color from a light orange-pink to a deep orange-red. Here is an image I found online that seems to be of ...
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How was the cama's life expectancy computed?

A cama is a hybrid between a male dromedary camel and a female llama. The first cama was born on January 14, 1998, yet on the Wikipedia page it is said that a cama's life span is 30–40 years. How was ...
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How do I read a sequence logo?

I'm looking at a paper that uses several sequence logos to illustrate the consensus sequence of certain sites. Here is the most important of the sequence logos I'm interested in: The explanations I ...
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What kind of event would cause the current Mitochondrial Eve to be replaced by a new one?

Apparently all living humans are matrilineal descendants of a single woman who lived 200.000 years ago. She is called Mitochondrial Eve. But at the time she lived there was a different matrilineal ...
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Can an organism obtaining a part of its genome via horizontal gene transfer be called a “hybrid”?

Wikipedia definition of "hybrid" offers many competing definitions. But most seem to be centered on sexual-reproduction gene transfer. Is there an official (in a textbook or widely accepted peer ...
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Why babies cry after they are born?

Well I have noticed that almost all of the babies cry after birth, but some of them (1 to 1,000,000? births) don't cry. So, we have: Why is this happening (the cry after birth)? Also why animals ...
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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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Horizontal gene transfer from humans

It is known that some viruses embed themselves in the human genome. Is there a mechanism by which human genes can be transferred to other animals or plants by means of viruses shuttling them from ...
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How is the exogenous DNA protected from degradation during bacterial transformation?

During transformation, a bacterium can take up DNA from its environment. A small fraction of bacterial species are known to be naturally competent, meaning that they can engage in this sort of ...
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Is the number of legs in myriapoda determined entirely by the genome?

Myriapoda (comprising, among others, millipedes and centipedes) can have hundreds of legs (Illacme plenipes having up to 750 legs). Interestingly, the number of legs (or leg pairs) appears to differ ...
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Genetic expression in interspecific hybrids

Referring to interspecific hybrids, I have the following two questions:- Quoting from wikipedia:- The offspring of an interspecific cross are very often sterile; thus, hybrid sterility prevents ...
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Why is polyploidy much more common in plants than in animals? [duplicate]

There are very few animals with polyploidy like salamanders. Why is it that polyploidy is so uncommon in animals? On the other hand there are numerous examples of polyploid plants. If ut something to ...
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Is the theory of evolution being disproved by bats?

For some species the Darwin's theory evolution makes perfect sense. I can easily imagine how, for example, the giraffe has evolved to its current appearance: the natural selection was favoring ...
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Why is the strength of genetic drift inversely proportional to the population size?

I saw a concept on the Internet that says "the strength of genetic drift is inversely proportional to the population size". I don't know why they are inversely proportional? Can somebody explain? ...
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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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Is it possible for a child to grow taller than their tallest parent?

I have heard that offspring can't grow taller than either of their parents but I've also heard that sometimes some gene activation can skip generations. Is it possible for a child to grow taller than ...
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What are the function(s) of Alu elements in the cell?

My 2008 biology book (1) states that some 10% of the human genome consists of relatively short (~300 nucleotides long) Alu elements which do not code for proteins but many of which are transcribed ...
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Father with mutated mtDNA- why isn't his offspring at risk?

Mothers transmit their mitochondria (and therefore mtDNA) to their offspring and fathers don't. Lets assume that father had a mutation of the gene that encodes mtDNA, would then be his offspring at ...
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Theoretically, is domestication of (virtually) any animal possible?

Looking at ones that manage well alongside us human animals, such as dogs and cats, we see that this is possible for evolved, distant animals to have heritable, preferable traits around people. ...
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Is DNA actually like source code repository?

So after reading articles like "People Use Just 8.2% of Their DNA" etc., and thinking a bit... I got this idea: What if DNA is actually like a software source code repository? You know, it has "...
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does order of genes in a chromosome matter?

does the order of genes within a chromosome matter? or is the main thing that the genes are there. so for example, our DNA is very similar to that of apes not only by the genes themselves but also by ...
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Are there any DNA base sequences that are fully conserved between the genomes of all humans?

That is, they don't differ throughout the entire population. I understand of course that we can't DNA sequence every human, so by "fully" I mean there's an incredibly small probability of there being ...
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What is an operon?

What is an operon in a eukaryotic cell, and how does it regulate the expression of genes? I've already read Wikipedia, but it is not enough clear to me. Unfortunately my knowledge in genetics are very ...

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