A change in an organism's genomic sequence.

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3k views

What is the standing genetic variation?

I am reading this review. In the first part, the author introduces Standing Genetic Variation, described as: STANDING GENETIC VARIATION Allelic variation that is currently segregating within a ...
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2answers
91 views

Why mutations in genes involved in general processes like DNA repair increase the risk of developing specific types of cancer?

For example, mutation in MHS2, which encodes a protein involved in the repair of mismatches that occur during DNA replication, dramatically increases the risk of developing colon cancer. (There are ...
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4answers
544 views

How does HIV mutate into other strains while keeping their virulent phenotype?

How does a virus like HIV mutate into so many strains, and yet all of them are harmful to our immune system? What gives this virus the ability to mutate so efficiently?
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525 views

What is the modern state of the theory of evolution?

When I studied biology at my medical school we used to learn things about a century old: the famous Darwin's voyage on "Beagle" to the Galapagos Islands, the classical triad of his Theory of ...
7
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4answers
314 views

How does Darwinian Evolution work?

Let me explain... A friend and I read some articles, part of a Biology book, and watched a video on evolution. We then tried to explain what Evolution is to each other. My friend said that Natural ...
7
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1answer
583 views

Can cancer cells in the same person, organ, and origin have different DNA?

Is it possible for cells from the same tumor to have different genetic material, and if so, to what degree is it possible (how fast do they mutate) ?
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2answers
171 views

(How) can a pink grasshopper exist?

I saw this foto on Reddit recently: Is this possible? How can a grasshopper become like this? Is this just natural genetic mutation?
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2answers
386 views

Ethidium bromide and mutagenesis on cloning

When performing a DNA cloning, sometimes PCR amplicon is run in agarose and it is detected by ethidium bromide marking under UV light. After that, gel is sliced, DNA extracted from gel....... until ...
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3answers
661 views

Why cancer mutations do accumulate sequentially?

According to Knudson hypothesis, cancer mutations accumulate in order. Statistics says, that cancer probability increases as sixth order of age, which may mean six consequential steps to cancer. But, ...
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2answers
119 views

Effect on fitness of mutations

What is the distribution/probability density function (PDF) of impacts on fitness of new mutations? I very welcome any partial answer that does not give the whole PDF but just some information ...
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1answer
42 views

Dominance/recessivity of new mutations

What is the distribution/probability density function (PDF) of recessivity/dominance of new mutations? I very welcome any partial answer that does not give the whole PDF but just some information ...
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1answer
206 views

Carcinogens, how do they work?

The easiest carcinogenic thing for me to grasp is radiation, as it directly messes with DNA. Then it seems there are other compounds that simply mimic hormones, but these shouldn't necessarily cause ...
3
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1answer
1k views

What is the difference between Single Nucleotide Polymorphism (SNP), Mutation and Structural Variation(SV)?

This is a question which plagues many people and today I was wondering it myself while writing a grant. Indeed, I've seen many people use the terms interchangeably, but they are all very different ...
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196 views

What errors can occur during DNA replication?

When there is an error in copying DNA (a mutation), what exactly goes wrong? If G goes with C and A goes with T, I don't see how that part can mess up. Is the idea that when the double helix is ...
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1answer
113 views

What specific mutations can cause an apoptosis mechanism to malfunction?

What specific mutations can cause the apoptosis mechanisms in a cell to malfunction? Are any such mutations 'reversible' , somehow or are they generally permanent? what kind of mutations can happen ...