5
votes
0answers
73 views

Why do some medicines induce sleep? [closed]

I have seen lot of people sleep or say that they are feeling sleepy after taking some medicines. Why? I mean, if a medicine acts on some cell of the body because that cell has got its receptors and ...
11
votes
0answers
88 views

What have the L-systems (Lindenmayer systems) been actually used for in biology?

Wikipedia: An L-system or Lindenmayer system is a parallel rewriting system and a type of formal grammar. L-systems were introduced and developed in 1968 by Aristid Lindenmayer, a Hungarian ...
4
votes
1answer
88 views

Identify bee in photo (found in Utah, USA)

A friend took this photo of a bee in his back yard in central Utah (© Jon Mott, CC-BY 3.0). I have no formal training in systematics or entomology, so to me everything looks like the bees' poster ...
1
vote
0answers
145 views

Where do the H+ ions come from in light reactions?

In the light-dependent reactions of photosynthesis, H+ ions pass to the thylakoid space. Where do these protons come from?
1
vote
0answers
33 views

Calculating the canopy size (crown) of a newly planted tree at a future date

Assuming that one knows the maximum area of the canopy and the age of the tree when it achieves this. And given an initial canopy size from the nursery. How would I calculate the canopy size at a ...
48
votes
1answer
3k views

What could cause a forest of bent trees?

While hiking on the northern Idaho-Montana border, I encountered a large area where virtually every tree is bent at the base in the downhill direction. Only the very largest and very smallest trees ...
3
votes
2answers
485 views

What does this equation about DNA replication mean?

Could someone help me understand this equation please? I found it in a paper which said that it was DNA replication, but why? $\ce{dNTP + dNMP_{n} -> dNMP_{n +1} + PPi}$ I found that dNTP means ...
5
votes
1answer
100 views

Does the anatomy of our hand result in (computer) mouse-accuracy that varies by direction of movement?

First off, I apologize if this isn't the right stackexchange sub-site for asking thsi question. I was torn as to where I should post this question: it could plausibly belong in Biology, User ...
2
votes
1answer
168 views

Can you recharge without sleeping? [closed]

Sometimes it's difficult falling asleep for almost an entire night. You might feel like getting up and being productive instead, or 'pull an all-nighter'. Or you can try to simply lay in bed to relax ...
2
votes
1answer
88 views

Has anyone modelled calcium oscillations using Matlab software? [closed]

I have been trying to model calcium oscillations using MatLab, but I cannot obtain the oscillation. I created a function where I put all the equations and used ode15s to call the function. I have ...
3
votes
1answer
51 views

How does tearing work?

I found the question about tear gas very interesting. Shigeta says there that crying helps the cells of the eye to wash themselves clear of the toxic components in the tear gas. Does non-emotional ...
4
votes
1answer
50 views

Crow branch pecking behaviour

I was walking through a small park when two crows started cawing at me, and followed me, flying from tree-to-tree as I walked. I speculate that this is a territorial or protective behaviour, but what ...
4
votes
1answer
104 views

Phosphorylation-Dephosphorylation : ATP-driven VS spontaneous

Is protein dephosphorylation most commonly spontaneous (without need of ATP)? I came across some papers that mention it, as well as the opposite case (ATP-driven), but I can't figure out which is ...
2
votes
0answers
30 views

What are all of the currently known variations of the G zipper motif?

The G zipper motif is found in transmembrane proteins at an above random frequency and there are models explaining how it might help with multiple transmembrane intra-membrane helix bundle assembly. ...
2
votes
2answers
136 views

Why do many DNA solutions contain additional compounds?

DNA solubility data in only water is scarce. A previous question asked for a quantification of DNA solubility in water. It seemed like it would be easily answerable, however isn't quite that simple ...
4
votes
1answer
27 views

Accuracy of best plant growth models?

Given a plant $P$, predict its height $H$ at time $t$ since planting given some environmental variables $E_1, \dots, E_n$. How accurate are the state-of-the-art models for such thing? What data is ...
7
votes
1answer
413 views

Toronto spider identification

I found it in Toronto, Ontario, during early June, 2015. When prodded it seemed to jump around, or at least to move very fast. I can also post a short video of it if needed.
2
votes
1answer
59 views

Animal identification (larva)

I found a tiny, white animal in my mouth on the morning of June 28, 2015, in Toronto, Ontario. Luckily I don't seem to have hurt it. I was eating some sunflower and pumpkin seeds at the time. I ...
10
votes
1answer
86 views

Can a lizard shed a regrown tail again?

Some lizards are famous for their ability to voluntarily shed their tail to elude predators (Autotomy). After a while, the tail will be regenerated, though with slightly different qualities, as ...
5
votes
1answer
80 views

Parents are Rh +ve and child Rh -ve

Suppose the two parents of a child have blood groups A+ve and O+ve, and the child has O-ve type. For blood group, there are two alleles. Since the child has O, the father must have one 'A' allele and ...
5
votes
1answer
54 views

Evolution of diversity and extinction resistance

I saw a comment on an answer to another question that touched on an interesting topic: keeping diversity is useful for parameter exploration or to adapt to future environmental change My initial ...
6
votes
2answers
939 views

Are we more attracted to people of the same ethnicity? [closed]

Are humans more attracted to people from their own ethnic groups? I ask this because most of the time people have relationships with people of their own ethnicity, and I wonder if it's purely social, ...
3
votes
1answer
103 views

What is this small black bug found in Turkey?

What species is this? It was found in Turkey. It was dead, I did not kill it.
1
vote
2answers
227 views

Autotrophic and heterotrophic organisms in anaerobic condition

Can both heterotrophic and autotrophic organism survive in anaerobic conditions? If an autotrophic organism does not produce carbon dioxide but requires oxygen, it should not be present in anaerobic ...
2
votes
2answers
59 views

Database of medically validated SNPs

I'm looking for all possible sources of clinically tested human SNPs. There is a handful of databases that store SNPs (like dbSNP), but I only need those that have validated presence/absence of ...
17
votes
3answers
2k views

Why does the face turn pale in dangerous situations?

I know what the effects are of a dangerous situation on the brain, i.e., an activation of the hypothalamic-pituitary-adrenal (HPA) axis which eventually results in an increased heart rate and elevated ...
0
votes
1answer
90 views

Which pair of primers should be used to amplify the ORF in PCR? [closed]

So I want to choose the correct set of pair of primers to amplify the ORF of the gene that corresponds to amino acids in a protein. The start and stop codons are underlined. (I know that these need to ...
1
vote
0answers
32 views

How to be a Noah-esque biopirate and store the genes of every plant and animal [closed]

Preamble. Please criticize this idea. It is too romantic to be possible. All of the news about the sixth extinction got me thinking about it. Thanks The price of DNA sequencing for humans has ...
2
votes
1answer
43 views

If a trait does not appear to be advantageous to organism, why does the organism have it? [duplicate]

Why do organisms have some traits that do not appear to have any evolutionary advantage?
4
votes
0answers
45 views

What is the meaning of conservation site in miRNA-mRNA pairing context?

I am not biologist and just work in Bioinformatics field. Does anyone know what is the meaning of conservation in the context of miRNAs and their pairings to mRNAs? Example: Each of these duplexes ...
1
vote
0answers
279 views

IC50 and area under the curve

I was hoping to get some clarification on how drug response data (i.e. IC50) are presented. On publicly available datasets like Genomics of Drug Sensitivity in Cancer, area under the curve (AUC) ...
5
votes
2answers
142 views

Exhalation while holding breath

If you inhale to your maximum capacity and hold your breath for an extended period of time, it begins to feel uncomfortable; slowly releasing your breath at this point seems to provide relief from ...
0
votes
0answers
40 views

Why do human have continuously-growing hair on their head? [duplicate]

Why do hair continuously grow on human heads, while the same doesn't happen on other parts of the human body? Where there are hair, they only usually grow to a fixed length; but they seem to have no ...
2
votes
0answers
701 views

What causes head hair to be different than body and face hair?

If you feel your head hair, it typically feels a lot softer and is easier to manage (comb, brush, fix) than a lot of other hair on your body - specifically I'm thinking about beard hair and pubic ...
2
votes
1answer
147 views

Which process is right to describe V(D)J recombination? RAG-1 and RSS recurring process

I'm studying V(D)J recombination. I think I have two incompatible books about explantaion of the process. Which is right? In Molecular Biology of the Cell 5th Ed., firstly RAG (-1?) combines to RSSs ...
4
votes
3answers
1k views

Why is wind cold for humans? [closed]

Coming out of the pool the other day, I felt very cold because I was wet and the wind picked up. My idea is that a "cold" feeling should be associated with low temperatures, but it's indeed wrong. ...
0
votes
1answer
32 views

is left brachiochephalic vein and left pulmonary artery is same?

I am reading about ligamentum arteriosum which connects the left pulmonary artery and descending aorta. But I am seeing that if any figure shows left brachiochephalic vein it does not show left ...
3
votes
2answers
95 views

Deciding a reasonable threshold for copy number variation in a CNV (SNP array) TCGA dataset

Is there a methodology to select a reasonable threshold for copy number variation in a CNV (SNP array) TCGA dataset, to define when there is a significative alteration? Can I download CNV data for ...
26
votes
6answers
3k views

If a trait would be advantageous to an organism, why hasn't it evolved?

If a trait would be advantageous to an organism then why hasn't it evolved yet? Conversely, if a trait is not advantageous or mildly disadvantageous, why does it exist? In other words why does ...
3
votes
1answer
39 views

Why is the administration of exogenous Anti-D not harmful to the foetus?

Haemolytic disease of the newborn can result from Rhesus incompatibility in utero. In this disease a Rh-ve mother becomes exposed to the antigens of a Rh+ve foetus by fetomaternal haemorrhage causing ...
1
vote
0answers
23 views

Genetic tests on S. cerevisiae to determine mutation locus on genes

I am studying the metabolism of galactose in the budding yeast Saccharomyces cerevisiae. After a random mutagenesis screen, several mutant strains were isolated that grow well in glucose but are ...
1
vote
1answer
67 views

How does the structure of the pancreatic acinar cell relates to its function?

So the pancreatic acinar cell synthesizes, stores and secretes digestive enzyme precursors called zymogens e.g. pepsinogen. The structure of the acinar cell shows that there is an apical and basal ...
-1
votes
3answers
161 views

Immortality Gene? Really? [closed]

I read somewhere in the internet and wondered if human genes have deactivated immortality genes locked somewhere in the DNA strand. Is this statement true? What does it mean for human lifespan?
0
votes
0answers
57 views

Can Kit fox and Red fox produce offspring?

Can a Kit fox (Vulpes macrotis) and a Red fox (Vulpes vulpes) together produce offspring? Would such a hybrid be fertile?
8
votes
2answers
269 views

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 ...
4
votes
2answers
52 views

If one endures the same form pain over a long period of time, would the pain begin to lose intensity?

Metaphorically thinking, if one endured the pain of constant burning for decades, would the pain slowly lose its strength?
2
votes
1answer
69 views

System biology and evolution: Book-recommendations

I have relatively good knowledge in evolutionary biology and in population genetics. I am getting more and more interested in the evolution of ... genetic developmental processes gene interactions ...
7
votes
1answer
807 views

Lumosity.com? Is it based on science?

I always see these Lumosity adds on TV, and I personally feel they are just trying to "sell me something". I did some layman's research(wikipedia) and read that "Studies of Lumosity's effectiveness ...
6
votes
3answers
370 views

Mutation That Loses Stop Codon

Someone asked this in my class and my instructor wasn't sure in her answer, doesn't anyone know what happens in protein synthesis if a mutation causes mRNA to not possess a stop codon? Would the ...
2
votes
2answers
129 views

Defining Resistance and Sensitivity Thresholds for IC50

I have a dataset containing IC50 data for each of my cell lines and up to 80 drugs. Basically for each drug I want to be able to define an IC50 threshold where if a cell line has an IC50 above that ...

15 30 50 per page