2
votes
2answers
114 views

Stay young by reinserting own DNA from years ago?

As far as I know, the DNA sequence becomes shorter every time a cell divides. A shorter sequence results in information loss and aging characteristics. As a countermeasure, shouldn't one stay young ...
1
vote
1answer
51 views

Can germs develop surfactant resistance in a harmful way?

Germs can develop antimicrobial resistance. It is a problem serious enough to deserve an FAQ page on the WHO website (http://www.who.int/mediacentre/factsheets/fs194/en/). But how about surfactant ...
3
votes
0answers
74 views

Could miniaturization be used to protect endangered large species?

In some animals (like dogs) size seems like it's controlled mostly by just a few genes (IGF1, and the genes that repress it). I'm curious: (1) Does other miniaturization takes a similar route (for ...
2
votes
1answer
90 views

Are there known 3- or 4-nucleotide RNA linkers with no RE sites?

Question is rather self-explanatory. I'm looking for a non-cleavable RNA sequence to act as an RNA linker. I mention 3- or 4-nucleotides only, but making such a sequence with 2 nucleotides is rather ...
2
votes
1answer
60 views

Is There An Initiative To Sequence The Genomes Of Critically Endangered Species?

I realize that there are many isolated efforts to sequence the genome of a particular endangered species such as the orangutan or the snow leopard. However is there a concerted effort to sequence the ...
6
votes
2answers
1k views

How many species did Carl Linnaeus classify?

How many species did Carl Linnaeus (senior) classify?
0
votes
1answer
260 views

A basic example of the interactions of 2 or more non-identical alleles leading to an advantageous outcome for an individual organism

Could someone help me out with a basic example of the interactions of 2 or more non-identical alleles leading to an advantageous outcome for an individual organism? Based on empirical research OR on a ...
3
votes
1answer
46 views

Process of Transcription

During the process of Conversion to Ribonucleoside Monophosphates the various ribonucleoside triphosphates break off their high energy bonds after linkage to the DNA.But the first ribonucleotide ...
0
votes
0answers
18 views

Why do our limbs and other body parts get numb/feelingless and then they start to tickle? [duplicate]

Why do our limbs (legs, arms) get numb/feelingless when they are under prolonged pressure or when one has crossed his/her leg while sitting for a long period? After we move it to a more relaxed or ...
2
votes
1answer
39 views

What is mRNA expression level?

I cannot find clear explanation of what is mRNA expression level, and how to measure it. I would appreciate if someone explained it or gave a reference. Thanks!
5
votes
1answer
250 views

Why does wood become darker when it ages?

I have lots of pieces of pine furniture which have different colours depending on how old they are. So, I just wondered why that is. I guess it has something to do with structures and chemical ...
1
vote
1answer
970 views

Evolution- Variations, adaptations and selective advantages

I am trying to understand Variations, adaptations and selective advantages and how they are all related. Feel free to add or correct me if I'm wrong- Variations are structural, functional, or ...
1
vote
1answer
3k views

What's the difference between protein and DNA behaviour during agarose gel electrophoresis?

I'm planning a science project about gel electrophoresis, and I'd like to know if there are any measurable, quantifiable (for example, things I could represent in a graph or chart) differences between ...
2
votes
0answers
51 views

Circadian rhythm in birds

Animals can use their circadian clocks to determine direction from the position of the sun. In a particular experiment conducted in Iceland, a bird, kept in a cage open to the sky, was trained ...
1
vote
1answer
113 views

Can we say that microevolution and macroevolution is fundamentally the same thing over different time scales?

This Wikipedia article states: Macroevolution is evolution on a scale of separated gene pools. Macroevolutionary studies focus on change that occurs at or above the level of species, in contrast ...
2
votes
1answer
259 views

recombination frequency problem

Three loci C, D and E are located on the same chromosome in this order. We found that the frequency of recombinants between C and D is 10% and that between D and E it is 20%. Assuming that ...
4
votes
1answer
298 views

Why do farts stink, but perfume does not?

Why is it that natural things like farts, poop, halitosis etc., from which we are always surrounded smell "bad"; whereas manufactured products, such as perfume or glue smell "good" to most of us? In ...
1
vote
1answer
66 views

How is sweetness measured?

Some time ago, I read in a newspaper--though I can't recall the details--a list of (mostly artificial) sweeteners and a list comparing how many times sweeter each was than sugar. How is relative ...
3
votes
1answer
254 views

Macroevolution vs. microevolution

Where is the line usually drawn between macroevolution and microevolution? I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes ...
1
vote
1answer
1k views

Is there any natural blue rose?

I had recently read an article that the possibility of having natural blue rose is extremely rare because of the absence of delphinidin in most roses. Are all blue roses just a product of ...
4
votes
2answers
10k views

Calculating Protein Concentration from Kilo Units (KU)

I am looking to purchase Pyruvate Kinase from the Sigma Website, they state the volume in Kilo Units (KU) i.e. 1, 5 or 25 KU. It also states there are 350-600 units / mg protein. Does this mean one ...
0
votes
0answers
48 views
1
vote
1answer
372 views

Why do you need the intrinsic pathway when you have faster extrinsic pathway?

There are two pathways in blood clot fromation; the extrinsic pathway and the intrinsic pathway. The extrinsic pathway is faster than intrinsic pathway because it has less number of steps. So, why do ...
11
votes
2answers
2k views

What is the difference between naive and adjusted p-values in a GWAS study?

What is the difference between a naive p-value and an adjusted p-value in the results of a GWAS study? See from this paper: After Bonferroni adjustment, a single gene, DCTN4 (encoding dynactin 4) ...
6
votes
3answers
363 views

Is there a hypothesis that attempts to explain patterns of species richness along all three energy-related environmental gradients?

My question is related to one of the oldest question in ecology: "What determines global patterns of species richness?". However, I want to focus on one particular part of this question, which has ...
2
votes
1answer
713 views

How many species have existed on earth? [duplicate]

I found a paper estimating the number of species currently living on earth. Now I'm wondering If anybody tried to estimate the number of species that have lived on earth. I'm familiar with problems of ...
1
vote
1answer
386 views

Question regarding Rate of Photosynthesis AP Biology Lab

We are doing a lab on the effects of light intensity/wavelength on the rate of photosynthesis in AP bio and we were asked to visit this website here: ...
2
votes
4answers
295 views

Are we inevitable in the evolution?

Suppose we wind time back to the instance when life emerged on Earth and let evolution start over again, will human beings or any other kind of self-conscious animals evolve ultimately, inevitably? ...
4
votes
1answer
73 views

Transcriptionally-mediated DNA damage

I'm researching the genetics of brain cancer, and finding a huge number of mutations in voltage-gated channels. It stands to reason that some of this DNA damage is due to the DNA being transcribed ...
3
votes
1answer
107 views

Chromatin shearing: what is it and what are the effects of high-sensitivity?

I am reading a paper which discusses a complex (MSL-DCC) involved in dosage compensation of the drosophila X-chromosome. Descriptions of the complex's structure and function are given in the papers ...
3
votes
1answer
69 views

How can chromatin state be measured?

I have some RNA-Seq data and I'd like to align it to the physical genome and see which sections of chromatin are geometrically open and being transcribed. The data are already sequence-aligned, and ...
4
votes
1answer
170 views

Bacterial chromatin binding data?

I'm looking for data - maybe CHP^2 data that shows chromatin binding to a prokaryotic genome under some specific conditions. Can anyone point me to a source?
3
votes
1answer
170 views

What are centromeres *really*?

I've gathered that a centromere is a a region* where the DNA is bundles up even tighter (around protein different to Histone) and chromatids are 'joined'. However I'm still mostly in the dark ...
21
votes
1answer
543 views

Regulation of chromatin structure

Recently, I reviewed the different levels of chromatin structure. The primary level is nucleosomes, where DNA is bound to histones, and has structural similarity to "beads on a string." The secondary ...
12
votes
1answer
425 views

How are epigenetic marks transmitted during cell division?

As far as I know, this is one of the biggest questions in the epigenetic field: how are the epigenetic marks like histone modifications propagated through cell division? A lot is already known about ...
10
votes
1answer
490 views

What is the functional and structural distinction between core (H2A, H2B, H3,H4) and linker(H1/H5) histones?

Many explanations of histone biochemistry isn't quite elucidating for the undergraduate student. How does histone structure (dimers, octomers) relate to their specific functions as core or linker ...
2
votes
1answer
33 views

What signals histone methyl transferases to function?

I wanted to find out if anyone knows what stimulates histone methyltransferases to function? I know that it is a process still trying to be understood, but I can't find anything that seems to direct ...
4
votes
1answer
149 views

How does “inheritance of methylation” of DNA and/or histones work?

What are the current models/ideas describing the mechanisms explaining inheritance of methylation on DNA resp. histone level? Is there evidance of this "setup" information being really ...
11
votes
1answer
73 views

What are the mechanism binding histone code with alternative splicing?

There are some bioinformatical considerations showing that there is a significant correlation of some between histone code and alternative splicing; but what are the hypothesis about the underlying ...
2
votes
1answer
134 views

Histone marks mechanism

I am slightly confused about the mechanisms that makes histone modifications associate with gene expression. That is, H3K36me3 is believed to be present in actively transcribed genes, H3K27me3 in ...
3
votes
4answers
2k views

Can the third sex be categorized as Male or Female?

Hijra are people who have a penis (not sure if sexually active) but look much like a female (perhaps for some feminine biological property). Wikipedia says they are "physiological males who have ...
4
votes
2answers
212 views

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 ...
2
votes
0answers
49 views

Embryo activity during seed dormancy?

What metabolic processes does a dormant embryo in a seed carry out? The newly produced seed will not germinate, either because of a lack of favourable conditions, seed hibernation, or because of a ...
0
votes
1answer
39 views

How does the body repair extracellular damage caused by glucose?

So we know that glucose is an aldehyde that can cause cell damage to the lysine and arginine residues on proteins through the Maillard Reaction (among other damaging reactions that glucose ...
9
votes
4answers
3k views

Why we have no enzyme to digest cellulose?

As we know, cellulose is the most abundant polysaccharide in nature. Why don't we have any enzyme to digest cellulose?
3
votes
1answer
51 views

How does your body ultimately recover from a cold?

Is it the eradication of the virus (assuming rhinovirus) by white blood cells? Or does your body somehow adapt to presence of the virus?
3
votes
2answers
61 views

Why are genes expressed as proteins rather than other types of bio-molecules?

I guess, we could infer that the structure of an amino acid has the same functional units as RNA is used to synthesise it. Therefore, from a logical point of view it would make sense that genes are ...
4
votes
1answer
283 views

Sexual selection in cats or other animals

I was wondering if you could answer some of my questions regarding sexual selection in cats (or any other animals). I would like to apologize beforehand for my incorrect term use. When it comes to ...
6
votes
4answers
8k views

How long can a naked human survive on Mars?

How long can a naked human survive at the surface of the Mars planet? For instance, let's say a worker's base takes fire while he sleeps, and he has to run to the emergency building 200 meters away ...
3
votes
2answers
134 views

Lactate and Diabetes

Why are lactate level high in diabetes? For example, Diabetes type II have resistance to insulin, and if they do it, their gluconeogenese should be working at high levels and, because of that, uptake ...

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