3
votes
1answer
206 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 ...
3
votes
2answers
2k views

Ill effects of urea and NH₃ on metabolism

What exactly does urea do that harms our body? Does it interfere with our cellular processes or disturbs the colloidal onchotic pressure of our blood? I have heard that NH3 damages the brain. What ...
3
votes
4answers
151 views

How did the activities of protocells become inheritable?

I have learned that first a protocell came to exist and its characteristics came to be passed on by genetic material. So how come genes for all the activities come to incorporate into genetic ...
3
votes
1answer
173 views

By what mechanism is Streptococcus bovis acting as a risk factor for colorectal cancer?

Streptococcus bovis bacteremia/endocarditis is considered a risk factor for colorectal cancer. What pathophysiological mechanism may link the two together?
3
votes
1answer
96 views

Low complexity region and relaxed selection

I'm reading a text (Wagner, 2007) on identifying positive selection. In paper, the author says that low complexity regions are known to be associated with relaxed selection. I'm trying to understand ...
3
votes
1answer
368 views

What factors govern the variable age of onset in Huntington's Disease?

"Huntington's disease (HD) is a neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and psychiatric problems." As we all know, this genetic disease ...
3
votes
1answer
231 views

Perception of distant lights without glasses

I am fairly short-sighted and wear glasses pretty much all the time. Naively, I would expect that when I take my glasses off, the image I see should look very much the same as as a photograph that's ...
3
votes
1answer
193 views

What is range of the number of individual organelles in cells

What is the range of the number of individual organelles in a cell? I am not a biologist but I understand that there's one nucleus and sometimes lots of mitochondria, so I am after the total number. ...
3
votes
1answer
128 views

205 nm UV-Vis readings

Typically we determine the concentration of proteins using a 280 nm reading. However, it is reasonable to use 205 nm. I was curious about the effectiveness of this method.
3
votes
1answer
787 views

Long term liquid food diet by blending/grinding all quality foods one would normaly eat, not any weight loss or prepared drinks

I want to know what are the effects of not using your teeth to grind foods but preparing it before eating with blending and grinding them into a liquid. Here I am not talking about any weight loss or ...
3
votes
1answer
53 views

What Makes A Pet Hypoallergenic

I know you can purchase dog and cat breeds that are hypoallergenic so those who are prone to pet allergies will have reduced allergies or none at all. These breeds are specifically bred for that ...
3
votes
1answer
188 views

Why seeds won't sprout given excess water?

What would cause a seed to not sprout despite showing signs of germination given excess water? Oxygen, temperature, and light were sufficient for germination and sprouting in seeds of a slightly ...
3
votes
1answer
294 views

Is there an “Adam and Eve” for each new trait during (not just human) evolution? [duplicate]

Do new beneficial mutation evolve simultaneously and independently with several individuals of the same specie or only with one specimen who then transfers it to all of the specie? In other words, ...
3
votes
1answer
230 views

Does an allergic reaction kill body cells?

I have wondered what actually happens in an allergic reaction that causes the symptoms such as pain, rash etc. Is it possible that the human body actually kills its own cells in the process?
3
votes
1answer
74 views

Historical recovery from mass extinction events

Is there a way to generally characterize how species "regrew" after the various mass extinction events happening periodically from 450 Ma to 65 Ma. Would the surviving species just start back where ...
3
votes
1answer
423 views

How do multiple replication forks function without 'colliding', and what is the benefit of this method?

I'm currently reading a little about DNA replication, and have come accross the following statement; Replication starts from a fixed point and is bi-directional ... In Eukaryotes, there are ...
3
votes
1answer
84 views

Can frequent ultrasound diagnostics be harmful?

Are there any short or long term effects apparent in tissues if a zone (or the whole) of human body is scanned with ultrasonic waves often?
3
votes
1answer
107 views

How is olfactory acuity rated/measured?

Acuity of one's sight is rated on the 20/20 scale. An online search appeared to indicate there is no comparable 'standard' to rate olfactory acuity. How is acuity of the olfactory system rated?
3
votes
1answer
97 views

What mechanisms do animals living in groups (herds, packs, swarms) have against spreading contagious diseases?

While for example a wolf pack provides protection to a sick wolf, increasing its chance of survival, there is a risk of infecting other members of the pack, decreasing their total chance of survival. ...
3
votes
2answers
821 views

Does finite rate of increase depend on mortality of individuals in a population?

As written in my lecture handouts, there two main factors in the Geometric Growth Model of populations: $R_{0}$ is the expected lifetime reproductive output. This way, for unicellulars, for example, ...
3
votes
1answer
39 views

Which part of oranges contain fiber?

I think it's pith, but here (non-english country) many chef suggest orange's vascular veins which look "fibrous" and have similar translated word with "fiber" itself. Please enlighten me which?
3
votes
1answer
79 views

Nucleotide frequencies in Kimura's two-parameter model

Here's an excerpt about Kimura's two-parameter model from Felsenstein's Inferring Phylogenies: "The model is symmetrical, and one can immediately see that, after enough time has elapsed, it ...
3
votes
1answer
2k views

Is “tonic activity” common for neurons firing in the brain?

I've been reading about Dorsal Raphe Nucleus, a serotonin- rich part of the brain. I noticed mentioning of "tonic activity" - regular pulsing that releases neurotransmitters. On top of this "tone" the ...
3
votes
1answer
504 views

How was the diversity between ethanol fermentation and lactic acid fermentation evolved?

Quite simply, some organisms metabolize glucose under anaerobic conditions via Glucose->(2) Pyruvic Acid->(2)Ethyl Alcohol. Some organisms, however, metabolize to lactic acid. When did such a process ...
3
votes
3answers
377 views

How is propagation of action potentials terminated once the “message” has been sent/received?

I'm thinking about neurons in the brain that are used for "thinking". As I read about action potentials, I see that an Axon is connected to a Dendrite of a neighboring cell and that there are ...
3
votes
1answer
438 views

Can Naegleria fowleri enter through the eyes ( example rinsing/splashing eyes with water)

I understand that it primarily enters the body through the nose by by "feeding on the olfactory neurons in the nose" as answered here in a different question. Would the nerve cells in the eyes present ...
3
votes
1answer
30 views

Mutation in axillary buds of trees overcoming self-incompatability?

I seem to recall from either reading or lecture that there have been instances of trees that are self-incompatible accumulating enough mutations in an axillary bud that the resulting branch was able ...
3
votes
1answer
71 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 ...
3
votes
2answers
164 views

What is the species of these mushrooms?

The mushrooms are gilled with a light-brown cap. The stem is widened to the base. What species is it? Is it considered edible? They are found in mixed forest in Moscow, Russia. They grow in the ...
3
votes
2answers
918 views

What is an organism?

The definition of an organism Wikipedia gives is An organism is any contiguous living system. I understand that these are not organisms according to this definition: A bird and a tree it's ...
3
votes
1answer
496 views

Can parents' learned traits be transmitted genetically?

I am wondering whether a behavioral trait (e.g. fear or stress experienced in the lifetime of the parent) can be transmitted genetically to its offspring? I understand that a behavioral tendency for ...
3
votes
1answer
79 views

Text/resource with information on all skeletal muscles and their motor units

Something analogous to an encyclopedia on baseball players with a list of all thier stats would be ideal. I'm not looking for just generic muscle names, locations and illustrations. Good answers ...
3
votes
1answer
108 views

Would a plant survive if it was watered using hard-water?

Hard water is water with high mineral/salt content. I'm told that a potted plant watered with a salt solution dries out sooner or later. Is this true? If so, would a plant survive if watered using ...
3
votes
2answers
317 views

Does body mass have a bearing on reflex speed?

A reflex is an unconscious action in response to some specific stimulus, e.g., blinking an eye, or pulling the hand away from a hot pin I know from school biology, and reading online that withdrawal ...
3
votes
1answer
91 views

Predictable microchimerism

I read in New Scientist recently that microchimerism occurs between previously born siblings and grandparents, not just the mother. Do we know which parts of the genome are likely to be transferred? ...
3
votes
1answer
5k views

Why is beta-mercaptoethanol often added to cell culture media

Many protocols suggest that beta-mercaptoethanol is necessary for growing cells. It is a reducing agent but what does it mechanistically do for your cells. When would one not add it.
3
votes
1answer
468 views

Could inhibition of progerin formation slow the rate at which a body ages?

According to wikipedia, progerin is activated in senescent cells. The protein itself is known to be the cause of a rare affliction 'progeria' - a disease marked by accelerated aging of the body. This ...
3
votes
1answer
336 views

Does chicken embryo form the disc called “discoblast” in the cleavage and blastulation of chicken?

This thread is related to my previous thread which is still unsolved mainly. I need to be able to compare chick and human cleavage and blastulation of zygote. My friend says that Chicken have ...
3
votes
1answer
47 views

How can you improve solubility of colloidally dispersed substances?

If you solve collidally dispersed substances then the particles can form large colloids. This may block narrow passages and diffusion into dense structures may become completely impossible. What can ...
3
votes
1answer
27 views

Can sexual selection operate in temperature dependent sex determining organisms?

Or more broadly, are distinct forms of genetic inheritance (ie. sex chromosomes) needed for sexual selection? My thinking was that since there are no sex determining loci, there could not be linkage ...
3
votes
1answer
61 views

What neuro-motor diseases cause the lower esophageal sphincter (LES) to malfunction?

Please note: This question is neither homework nor seeking medical advice. I'm simply asking for a factual, objective, biological explanation of the various neuro-motor diseases/illnesses that can act ...
3
votes
1answer
47 views

Why do men grow facial hair?

Ancestral facial hair. Our closest ancestors, the chimpanzee and bonobo, both grow facial hair around the mouth area. What is noteworthy is that this is the case in both males and females of the ...
3
votes
1answer
12 views

Is disease transmisson through milk consumption or meat consumption considered direct or indirect transmission route?

From an epidemiological point of view, is consumption of raw milk or meat considered as indirect or direct transmission ? Let's take the example of bovine TB. Is consumption of unpasteurized milk ...
3
votes
1answer
20 views

Why does low sequence diversity cause sequencing problems

When sequencers are processing sequence fragments, if there is little diversity at a particular bp locus this can cause problems for the sequencer. I have the superficial understanding that when a ...
3
votes
1answer
25 views

Fruit Fly Hybrids

I have a food waste bin in which I put fruit scraps. The fruits come from all over the world, mainly Europe though. I'm in the UK. I assume the fruit Fly eggs are already in the fruit, in which ...
3
votes
1answer
41 views

Is sequencing error a function of the nucleotide being read?

Checking out on Google Scholar, I can see that for Illumina (just to consider one example) the sequencing error rate is of the order of 0.001-0.01 per nucleotide. Talking about sequencing error, ...
3
votes
1answer
40 views

History: Do evolutionary and ecological processes occur at the same timescales?

Classically, it was thought that evolutionary processes occurred at a much slower pace than demographic/ecological processes. Nobody, ever thought about incorporating both processes into the same ...
3
votes
1answer
29 views

What would be the impact of depositing limestone in the oceans (to reverse acidification) on ocean life forms and biodiversity?

This question asked: What is the evidence it is feasible to reverse ocean acidification by adding large quantities of a base (bicarb soda)? The result was: Danny Harvey of the University of ...
3
votes
1answer
70 views

Is there a schema for how human behavior is genetically determined?

It seem one can distinguish three different kinds of genetic determinism of common patterns of human behavior: behavior that is directly wired into our nervous system, e.g. face-related mirror ...
3
votes
1answer
22 views

Why is it so hard to find the amount of biotin in food? [closed]

According to the WHO publications biotin is a thing we need. Although its non toxic, so you can't get too much. However, excluding a few (small) lists that deal exclusively with biotin content there ...

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