1
vote
1answer
57 views

Distribution of fitness in wild populations

If I get out in the wild observe wild populations and measure the distribution of fitness $f(w)$ in a given population. What will I find out? Will I observe a Gaussian distribution, a Poisson ...
1
vote
1answer
66 views

What is a sex-biased gene?

How do you define a male-biased gene and a female-biased gene as they are found in the abstract of this article.
2
votes
1answer
220 views

Definition of Sexual Selection?

How do you define Sexual Selection (SS)? (One might want to subdivide SS into intra- and inter- SS to answer) Is SS clearly different from Natural Selection (NS)? Is SS nested within NS or are NS ...
3
votes
1answer
54 views

Is there a superterm combining “animal line” and “cell line” in disease models?

Biologists researching diseases will frequently use animal models. The way I understand it, there are species of animals, such as "mouse", and lines of mice, such as ...
2
votes
1answer
234 views

Fatty Acid Synthesis

I have a problem in my reasoning on the fatty acid synthesis in the human body. In the synthesis process you have this homodimer. So the synthesis starts with the transfer of a acetyl group from ...
9
votes
1answer
196 views

What is this snake

I took a picture of this snake in Switzerland (Geneva Area): It looks to be an adder but cannot be sure about which species. In Switzerland we have two kinds of adder: Vipera berus Vipera aspis ...
3
votes
1answer
36 views

Do axon grows after cutting/damaging of some of its part?

Do axon grows after cutting of some of its part to near original place? Do axon restores after local damaging of some of its part? I take https://class.coursera.org/neurobio-001/ classes and learn ...
5
votes
3answers
348 views

How does a biologist decide when she has enough results to publish a paper?

Biology is so exciting! Answering a question leads to thousand more questions! There is no limit to how much one kind find out about a phenomena… So I have always wondered how someone can ...
7
votes
2answers
102 views

Neuronal Architecture of the Brain

To what extent do brains (e.g. of humans) contain recurrent connections? I am studying artificial neuronal networks and frequently encountered the statement, that recurrent neural networks are ...
2
votes
1answer
169 views

Exercise vs stimulants, which is more effective for promoting concentration?

Stimulants are the first choice for treating ADHD. But we also know that exercise helps to improve concentration. We know that both stimulants and exercise increase bloodflow to muscles and to the ...
8
votes
2answers
1k views

Does a walk after a meal help with digestion?

I am a bit confused with the notion that "walking after meals helps you in digestion ", Some say that it helps, whereas others oppose it. Can someone come up with a valid explanation for this?
0
votes
1answer
311 views

Why do bananas turn black after some time? [duplicate]

Why do bananas turn black after some time? Please don't just give hypotheses but concrete references to experiments
2
votes
2answers
504 views

Why isn't phosphorus or nitrogen a limiting nutrient for animals?

Nitrogen and Phosphorus are usually the limiting nutrient for plants, especially for algae. Phosphorus is used for DNA, ATP and phospholipids, and Nitrogen is used for pretty much every protein a ...
6
votes
1answer
89 views

What's the biggest obligate anaerobic organism discovered till now?

Beside many anaerobic single cell organisms, there are some annelid worms that are obligate anaerobic at least in their early development stages. Probably, due to low concentration levels in nature, ...
2
votes
1answer
103 views

Trimming of tRNA precursors

From Molecular Biology of the Cell (4th edition) by Bruce Alberts et al. (Chp 6, Pg 338) : Both bacterial and eucaryotic tRNAs are typically synthesized as larger precursor tRNAs, and these are ...
7
votes
1answer
227 views

Is fluoride toxic, and how worried should I be about it?

A recent flurry of "fluoride is bad!" posts are appearing on my social network news feeds. Usually I can simply ignore them after a brief look, but this one, stemming from a recent article in The ...
20
votes
3answers
4k views

Were there any flying dinosaurs?

I've seen some articles which came in contradiction with each other. The first article was talking about flying dinosaurs, dinosaurs with feathers and so on. A couple of other articles are talking ...
13
votes
2answers
823 views

Are there issues with filling PCR tubes to capacity?

I'm planning to scale up a PCR reaction, and I'm wondering if filling the PCR tubes to the maximum volume of 200 ul would be a problem. It would mean a lot less pipetting as I would only need 1/4 of ...
1
vote
2answers
125 views

problem with natural selection [duplicate]

I fail to see how natural selection can build any kind of new functionality. New functionality in a design requires sacrificing a complex series of meanwhile useless steps before the new ...
0
votes
1answer
41 views

Protoporphyrinogen (IX) formation in heme synthesis

This picture shows one of the steps of heme synthesis. In this step two propanoate groups of coproporphyrinogen III are decarboxylated to form protoporphyrinogen IX. The enzyme that catalyses this ...
7
votes
2answers
570 views

Help with the Price equation

The Price equation describes mathematically the evolution of a population of units from one generation to the next. $\bar{w}\Delta \bar{z}$ = $Cov (w_i,z_i) $+$ E(w_i\Delta z_i)$ I would like ...
3
votes
0answers
101 views

Is there a correlation between brain size and amount of sleep? [closed]

As far as we know, sleep seems to be the part of the daily cycle when executive functions are resting and memories are fortifying. Many, but not all, of the functions that become dysfunctional upon ...
2
votes
0answers
69 views

What are the known natural biochemical reasons for a dead human's body not fully decaying? [closed]

What are the known natural biochemical reasons for a dead human's body not fully decaying (decomposing)? EDIT: I am interested in a scientific explanation of those cases, in which human body would ...
1
vote
0answers
45 views

What is the suitable terminology to describe this study approach?

I need to know the correct term(s) which are usually used in the parlance of both biology and bioinformatics for this study approach: About 11 transcripts were investigated using qPCR for a number of ...
5
votes
3answers
401 views

How do you merge SNP data with a reference genome?

My Data I have a 23andMe file listing SNPs in the form: ...
2
votes
1answer
244 views

What cells don't have a primary cilium?

It is often stated that most cells in the human body have a primary cilium. Which ones don't? For which cells is it unknown?
1
vote
1answer
185 views

A question related to qPCR analysis

Here is the thing. I am using a method, called TU-Tagging, to isolate cell type specific RNA. You can find more about the method here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2783170/ To explain ...
2
votes
1answer
81 views

Does digit 1 have an extensor sheath?

Extensor digitorum and extensor digiti minimi both insert into the extensor hoods of digits 2-5 (or just 5 in the case of e. digiti minimi). In every source that I can find, extensor pollicis longus ...
10
votes
3answers
1k views

How best to count bees entering and leaving a hive to measure hive activity?

This is my first question here, so I apologize for all mistakes I could have possibly made. I'm a high school student in East-Central Europe and I need to complete some research for a biology contest ...
3
votes
1answer
156 views

What is the evolutionary cause for various finger lengths?

Why are the lengths the way they are with middle finger the longest?
4
votes
2answers
53 views

Could humans choose to establish fibre digesting colonies in our guts?

Humans don't digest fibre, and nor do any animals, but some creatures have micro-organisms (bacteria, I'm guessing) in their gut which digest fibre for them. My question is, could humans take some ...
3
votes
2answers
264 views

What is atrial fibrillation? [closed]

I am wondering exactly what a-fib is (causes and symptoms). I would really appreciate having a sample of an EKG with it (because in my limited research, I have found it nearly impossible to find just ...
4
votes
1answer
518 views

how is the plasma membrane repaired after endocytosis?

When the vesicle is swallowed of course the lipid layer internalizes. My question is how will the top segment of membrane will bind back together when that vesicle took the membrane with it inside ...
5
votes
0answers
105 views

Where can I get numerical data for the PAR (photosynthetically active radiation) curve?

I'm trying to do some rough figuring to calculating efficiencies of various light sources for growing plants. I'm hampered, however, by the lack of a curve to multiply by the spectrum of light ...
3
votes
1answer
578 views

Will the increase in atmospheric carbon dioxide lead to larger insects?

From my understanding, the increase in atmospheric carbon dioxide will also increase oxygen levels. That makes me wonder if in the near future insects will grow larger than they are today, since their ...
9
votes
1answer
240 views

How can antibiotics damage the ear?

What is the mechanism by which aminoglycoside antibiotics (such as streptomycin and gentamicin) damage the mechano-sensory hair cells of the auditory and vestibular system? (Could this be seen as ...
1
vote
1answer
60 views

What does “developmentally programmed” mean?

What does the term "developmentally programmed" mean? I can't seem to find a definition anywhere. What would the alternative (i.e. not developmentally programmed) imply?
1
vote
1answer
50 views

About the quality of microsatellites

I built a script to detect microsatellites in a FASTA file. However, there are thousands of possibilities. So, my question is: what are the markers of a "good" or "useful" microsatellite? - How ...
3
votes
1answer
571 views

Antihistamine's effect on insulin secretion and tiredness

Antihistamines are known to cause tiredness. The essential hormones of the body are insulin (glucose), parathyroid hormone (calcium) and aldosterone (Na-K ATPase, sodium). I am thinking how this ...
3
votes
1answer
3k views

What's the physical meaning of Svedberg unit?

Sedimentation coefficients, using a centrifuge, are expressed using Svedberg unit (symbol S, sometimes Sv). Wikipedia states that $S = 10^{-13}$ sec but I also saw in a book that actually $S = ...
0
votes
1answer
144 views

Tc and Th1 interaction and viral immune response

Tc is T cell which can give T killer cells and T helper cells. T helper cells (Th1) see the pathogen presented by antigen presenting cells (dendritic cells and macrophages). They then secrete antigens ...
1
vote
1answer
274 views

Various Genetic Loads and their Definitions

In population genetics, we talk about several types of genetic loads (also called just loads). I am asking for a exhaustive list and a short definition. Here are for example some genetic loads that ...
2
votes
1answer
57 views

Effects of having too much vitamin D?

I saw there was another question about vitamin D; however, I do not believe this is a repeat. What are some of the effects/side effects of having too much vitamin D in your body?
10
votes
3answers
618 views

Can genes change as we age?

Let's say you're a 23 year old man who impregnates a woman. Will your genes be the same if you were to impregnate another woman at age 35? Will your genes in those 12 years have ...
2
votes
1answer
220 views

Two-fold cost of sex and r/K selection theory

This article cites a bunch of articles (I haven't been through them) that the effect of the two-fold cost of sex is "reduced" in stable environment or in K-selected environment. It says: [..] the ...
2
votes
1answer
92 views

Converting Ensembl Compara gene tree DNA alignment to corresponding amino acid alignment

I have Ensembl compara gene tree alignments (Compara.gene_trees.57.fasta.gz downloaded from ftp://ftp.ensembl.org/pub/release-57/emf/ensembl-compara/homologies/) in nucleotide format. According to ...
1
vote
0answers
59 views

Vitamin D oral intake, transportation and absorption

Several factors affecting vitamin D and its active form absorption and storage acidity of stomach (not significant effect) cytopathic effects of viruses cytopathic effects of bacteria where the ...
2
votes
1answer
100 views

H O N C alternatives for organic life?

Most organic structures built from hydrogen, oxygen, nitrogen and carbon. They are represent 1-,2-,3-,4- bond relations (chemical valence) which allow to build variety of chain structures. Are there ...
2
votes
1answer
38 views

How many areas are there in Brodmann map?

I read Wikipedia claiming 52. I heard that this can be extended to 54. I see there is no limit of having more areas - just better understanding of the neuroblast migration and fibroblast too, ...
1
vote
0answers
29 views

Prenatal hyperkinetic dysfunction and its effect on endurace

Do people with an hyperkinetic dysfuntion have a better endurance? Are they fitter in cause of their Dopamine-overdose or any other reason? I have a case, where someone does not do any sports, but ...

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