8
votes
2answers
100 views

Why don't McDonald's fries decompose?

So I was cleaning out my car and found a McDonalds French fry. as I don't eat anything in my car I know exactly who and when this fry is a result of. The when is + 10 months old and it could pass off ...
0
votes
0answers
14 views

Would blue light be effective to help average people when sunsets come much earlier in the day?

I know people with SAD (Seasonal Affective Disorder) benefit from blue light in the winter as night-time comes much earlier (in the UK, sunset is around 4pm in December, compared to 9pm in June). ...
1
vote
0answers
17 views

Physiological markers of some antibiotic resistance? [on hold]

I am studying antibiotic resistance on Physiology. I am particularly interested its effect on Physiology: heart rate blood pressure pacemakers of the heart mean electrical axis coordination of the ...
0
votes
0answers
17 views

STRING ID - allelic differences and splice variants

STRING has protein (amino acid sequences) mapped to a single gene ID. I have these doubts w.r.t STRING ID. I find that 1.All alleles of a single gene share the same STRING ID and 2.Especially ...
2
votes
0answers
23 views

Statistical method for characterizing the relationship between body mass and metabolic rate

There is a dataset that contains body mass ($x$) and metabolic rate ($y$) from many different organisms. It is common to fit the data to the model of the form $y=ax^b$ and estimate the parameters $a$ ...
0
votes
0answers
35 views

Speciation after origin of humans [on hold]

I have a strong conviction that homo sapiens are not any way special in choice of nature compared to any other species. Having said that we say that we started to appear around a million year or so. ...
2
votes
0answers
30 views

Native vs Immigrant plants [on hold]

Is this statement applicable to any known plant/region combinations? Plant species X, Y, and Z are truly indigenous to region R. Other "immigrant" species can be destroyed by drought or harsh ...
3
votes
0answers
19 views

Circulating factors affecting human health/longevity

Circulating factors present in young mice have been shown to promote rejuvenation of aged mice, suggesting that tissues have inherent capabilities to regenerate, and circulating factors may be ...
6
votes
2answers
84 views

Why does anxiety cause diarrhea or constipation?

Anxiety sometimes cause diarrhea, sometimes constipation, and sometimes both. It's interesting because it seems their underlying neurophysiology is somehow different. What are underlying physiological ...
18
votes
6answers
785 views

How is evolution possible in contemporary humans?

I would like to know if evolution is continuing to happen in modern humans, assuming things like existence of the nuclear family structure, fidelity to one partner, etc. It seems to me the answer ...
3
votes
1answer
43 views

Why does weight loss lower blood pressure?

I have read that weight loss is an effective lifestyle modification for people with hypertension, and systolic pressure may be reduced by up to 1-2 mmHg for every 1kg of weight lost. What is the ...
0
votes
0answers
28 views

What is a Good Essay Question for Photosynthesis? [on hold]

I'm a freshman in highschool, and we have a test on photosynthesis coming up next week. I was wondering what a good, all-inclusive essay question, that will cover the processes of light-dependent ...
15
votes
1answer
623 views

Why is the Krebs cycle considered a part of aerobic metabolism if molecular oxygen is not involved in any of the reactions in the cycle

Why is the Krebs cycle considered a part of aerobic metabolism if molecular oxygen is not involved in any of the reactions in the cycle? I originally thought that Krebs cycle was aerobic metabolism ...
21
votes
1answer
2k views

Can brain cells move?

I was discussing this with my brother. I'm pretty sure I read somewhere that they can move. Thanks EDIT: By movement I mean long distance migration (preferably within the brain only).
3
votes
0answers
25 views

How many cells are there in the apical meristematic tissue?

How many cells are there in the apical meristematic tissue? Looking at this picture... , I would tend to think that there are few hundreds cells in the meristem tissue. But I guess this is a ...
-3
votes
0answers
21 views

Dissolving or not? [on hold]

You have two beakers. One contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol ...
0
votes
1answer
6 views

Relation between trigeminal and facial nerve in sympathetic response

In my neuro-anatomy course notes I found that the facial nerve "uses" the trigeminal nerve to reach its targets. However, I have yet to find any diagram or reference that indicates how this is done. ...
-4
votes
0answers
38 views

What are the 5 most expensive machines that can be found in a bio-lab? [on hold]

What are the 5 most expensive machines that are specific to a biology laboratory? In this case the type of biology laboratory that specialises in molecular biology and bioinformatics (study of cell ...
5
votes
1answer
97 views

Mammal body density

Human body density is approximately 1 kg/l (same as fresh water) - which is not surprising (at first) given that we are 70% water, and is surprising (on a second thought), given that the other 30% can ...
1
vote
1answer
68 views

5,6-dihydrouracil and 5,6-dihydroxyuracil - how they arise in DNA?

5,6-dihydrouracil can be formed from cytosine after exposure of DNA to ionizing radiation under anoxic conditions [Ref]. What are other ways by which 5,6-dihydrouracil is formed in DNA? What about ...
3
votes
1answer
33 views

Do plants have preference for the form of nitrogen as nutrient?

In the nitrogen cycle (ecology), it is usually described that plants can use nitrogen in the form of ammonium (NH4+) and nitrate (NO3-). Do plants prefer one form of nitrogen over the other?
2
votes
1answer
48 views

Why do we have two of some organs, but not all? [closed]

We have two eyes, but we don't have two hearts. Why do humans have two of some organs, but not all?
6
votes
1answer
52 views

How to search for organisms by criteria such as growth substrate and overflow metabolites?

I'm looking for a database or a systematic way to search for organisms which meet certain criteria. My criteria descending importance are: growth substrate chemolithoautotrophy (on which substrate) ...
1
vote
1answer
38 views

Speciation of humans? [duplicate]

Since we homo sapiens (and all other species) are continuously evolving, are humans undergoing speciation based on our environment? OR has there been any difference across people that could say ...
3
votes
3answers
202 views

Extreme examples of protein translation/use coupling/decoupling?

What are known extreme examples of protein translation/effect coupling/decoupling? For example, examples of proteins that are immediately used at the time the have been translated and vice versa, ...
6
votes
1answer
51 views

Number of transcription factor genes in the human genome

What is the number of the transcription factor genes present in the human genome? Does this value differ compared to Mus musculus, Drosophila melanogaster, Arabidopsis thaliana, C. elegans and S. ...
4
votes
0answers
55 views

Long-term effects of antihistamines on mind and CNS [closed]

Can maybe someone share knowledge or guesses on the following questions: Does the prolonged use of antihistamines cause long-term effects on mind or CNS? Are there any known evidences of their ...
6
votes
0answers
46 views

B cell receptor editing

If a B cell contains two mu chains and two lambda chains and is self reactive can it go back and rearrange its kappa light chains? I'm not sure if it can only try to rearrange its lambda light chains ...
6
votes
1answer
120 views

How are bones growing, if bones are not connected to the brain?

If the bones are not connected to the brain, how is their growth controlled? This question is not a duplicate of the question Mechanisms of bone growth, as this question deals with how bone growth is ...
9
votes
3answers
152 views

What causes feeling of feet falling asleep to be delayed?

This answer explains the sensation of extremities "falling asleep" as a result of sustained pressure on a nerve. The answer links to an external web page that says that the feeling "quickly goes away ...
0
votes
0answers
31 views

Deactivation of plasma cells [closed]

Is it possible to deactivate plasma cells or B-cells? So far I haven't found many answers on the Internet or in Stack Exchange. Please help! Also, please include references. So my ideas were to use ...
6
votes
1answer
107 views

Why do we still have genetic disorders that show anticipation?

Anticipation whereby symptoms of genetic disorders occur earlier and with more severity as it is passed from one generation to the next. So wouldn't these inherited diseases over a few hundred ...
3
votes
1answer
91 views

How are arms different than legs?

Ok, this is a bit of a tangent question, but it came up yesterday and I didn't know the answer: How are arms and legs defined physiologically? For example, we say humans have two arms and two legs, ...
4
votes
1answer
172 views

Body size, what are the evolutionary trade-offs?

Background Considering just the "Kingdom Animalia" branch of organisms. It is clear that bigger does not necessarily mean better - there is large variation in body size... From the 94 µm long ...
4
votes
2answers
120 views

What governs the size of animal bodies?

Million of years ago there lived dinosaurs up to 36 m high. About 10,000 years ago lived Machairodontinae -compared to cats today they were huge. About 400,000 years ago lived Mammuthus trogontherii: ...
0
votes
0answers
28 views

coevolution by physical interaction between RNA sequences [on hold]

There are several items that relate to the concerted evolution between pairs of sequences (especially structural) rRNA as a consequence of physical interaction in tertiary, or even quaternary ...
-1
votes
1answer
23 views

Does a snake really digest part of its heart if they don't have enough food for a long time? [on hold]

I've seen this in a book, however I couldn't believe this. Googling it told me nothing.
2
votes
3answers
79 views

fastq-dump using mkfifo to stream data

So, fastq-dump has the ability to be run on just an SRA file accession number, such that the SRA is converted to FASTQ on-the-fly, and the SRA doesn't have to be written to disk. I'm curious whether ...
5
votes
3answers
90 views

Studying effects of alcohol on cells

I am wondering about the logistics of a simple experiment with say 3 types of alcohols, and various concentrations of each, with a control(s) I would like to research the effects of alcohol on ...
6
votes
3answers
2k views

What evolutionary adaptations cause trees to grow tall?

I think there are some obvious costs for trees to grow tall. Carbon and other nutrients costs, maintenance cost, energy cost (for growing, to bring water (and nutrients) up to the higher leaves, ...
1
vote
1answer
19 views

Can plants directly use sulfuric acid?

In the explanation of the sulfur cycle, it is often said that sulfur moves from the atmosphere to the ground by acid rain in the form of sulfuric acid. Can plants directly use sulfuric acid to ...
1
vote
0answers
25 views

How does a bacterial colony, grown in a nutrient medium, change the chemical composition of that medium over time? [closed]

In order to culture cells, the nutrient medium they are grown in must contain certain chemicals and trace elements (e.g. Hams medium, for culturing human cells, and a less demanding solution for ...
3
votes
1answer
20 views

Estimating RPM to RCF in Methods from Older Papers

I'm attempting to replicate a cell biology method from a 1958 Laboratory Investigation paper. The protocol is for the isolation of an extracellular matrix protein, and a key step is a centrifugation ...
3
votes
0answers
22 views

Well to well variation in thermal cycler fluorescence?

We have an old BioRad ICycler Thermal Cycler with MyIQ single color fluorescent detector. While it's meant for RT-PCR, we've been using it for melt curves and binding assays for different types of RNA ...
3
votes
0answers
31 views

Skin porosity in glans penis when erect

(Apologies if this is a too weird/inappropriate question in this forum. I only thought that I ask it since it happens to be part of human life.) The skin on a human typically blocks many substances ...
-2
votes
0answers
30 views

The ethics of ACST in full blown AIDS patients [on hold]

We've always been told that a traditional Allogeneic Stem Cell Transplant (bone marrow transplant) is unsuitable as a treatment option for those living with HIV due to the mortality risks it carries ...
4
votes
1answer
88 views

Does DNA analysis allow determining amount of chromosomes?

Nowadays it is possible to sequence the DNA of extinct species, such as the Neanderthals, the Denisovans, and others. Is it possible to determine, solely from the sequenced DNA or from known bone ...
-2
votes
0answers
31 views

PCR, writing methods section for a journal, I am quite inexperienced in writing, and was just checking in if this is okay [on hold]

Touchdown PCR was performed for site directed mutagenesis in a 25ul reaction volume of 2μl of template pET15B in combining 16μl of Nuclease –free deionised with 2.5μl of 10X Standard Taq Reaction ...
3
votes
1answer
37 views

Why do small fonts strain the eyes?

I understand that too much close reading will strain the ciliary muscles of the eyes. But what about small fonts? The contraction of the ciliary muscles is dependent on the distance not font size. In ...
3
votes
1answer
167 views

Bug Identification: Is this small tubular, black bug a bed bug?

So I found this tiny bug on my wall in the bedroom of my apartment. I estimate it is about 3mm long by 1mm wide. Is it a bed bug? It does not seem to match any of the pictures I've seen online. ...

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