1
vote
1answer
63 views

How is oxygen and carbon dioxide exchange mediated by hemoglobin? [closed]

Oxygen is transferred by hemoglobin from the lungs to tissues, while carbon dioxide is transferred by hemoglobin from tissues to lungs. How is this regulated bidirectional transfer mediated?
2
votes
1answer
121 views

Whole genome sequence analysis software

Please help to choose Bioconductor R packages and other software for the whole genome sequence data analysis and, in particlular, the goals of false discovery mutation rate, mutations exclusion, ...
1
vote
1answer
81 views

Why is sarcoma more prevalent and common in right heart?

Ewing's sarcoma or Ewing sarcoma is a malignant small, round, blue cell tumor. It is a rare disease in which cancer cells are found in the bone or in soft tissue. It is more common in right heart than ...
7
votes
4answers
13k views

Why do men have a higher hematocrit (red blood cell count) than women?

The hematocrit, also known as packed cell volume (PCV) or erythrocyte volume fraction (EVF), is the volume percentage (%) of red blood cells in blood. It is normally 45% for men and 40% for women. so,...
13
votes
0answers
2k views

Why do we experience temperatures below 37 degrees Celsius as 'hot'? [duplicate]

We always prefer to be in 20-25° C, although our core temperature is about 37°? Why is our skin temperature lower than our core temperature?
9
votes
1answer
840 views

Why do flies “rub” their front legs when resting?

I've noted that every time a house fly is resting on a surface, it appears to "rub" or "scrub" its front legs in a repetitive movement. And they do it continuously. Why?
7
votes
1answer
345 views

Can humans live without their right atrium?

The right atrium is one of four chambers (two atria and two ventricles) in the hearts of mammals (including humans) and archosaurs (which include birds and crocodilians). It receives deoxygenated ...
13
votes
3answers
4k views

Why does hair grow after trimming but remains at a constant length after a while?

Some hair especially body hair regrows after trimming but stops growing after a while. What is the mechanism behind control of hair growth and how is the length limit determined?
2
votes
1answer
1k views

Why is the Trendelenburg position used when placing and removing Central Venous Line catheters in the sub-clavian vein?

The title says it all. Why is it that patients are placed in the trendelenburg position when a catheter is inserted in the sub clavian vein? What would happen if the patient wasn't placed in the ...
2
votes
1answer
97 views

Why can blood vessel contraction be described as a second order system?

Suppose that the x-axis represents time, and the y-axis vessel diameter. Then this graph is claimed to roughly describe what happens when the blood pressure increases, then decreases. When the ...
6
votes
1answer
142 views

Chickens roosting, is it sleep or torpor?

At night when they roost, do chickens experience a state of sleep (meaning do they move from NREM1 to NREM2, NREM3 and REM) or are they in a state of torpor (reduced metabolic rate and decreased ...
11
votes
2answers
1k views

Do males of all sexual species have Y chromosomes?

I know for instance some cells are sexual, so, this got me wondering, do the males of all species that have distinct sexes have Y chromosomes?
8
votes
1answer
256 views

Why do we find some things disgusting and others delicious?

For example, why do I love paprika while my girlfriend hates it? Why do I find broccoli disgusting and she adores it? As humans, there are things we'd all agree on being awful, like rotten meat, for ...
2
votes
1answer
148 views

Using perceptual adaptation for enhancing realism of VR/other entertainment

I am quite a fan of the recent oculus rift VR glasses, but it does have several flaws over normal vision, most notably a much less wide field of view, the so-called screen door effect because of too ...
0
votes
1answer
38 views

Chemical reactions at the synapse

For my course project, I am thinking of listing out major chemical reactions that occur at synapses, along with their temporal characteristics. I could not find any textbooks to use as a starting ...
3
votes
1answer
398 views

Hydrogen Peroxide on Open Wounds

I know that H2O2 is a chemical with high oxidative potential. It can deliver nascent oxygen which can destroy bacteria. I understand that open wounds have cells that are dividing at a fast rate to ...
2
votes
1answer
231 views

Grafting vegetables onto fruit-bearing trees

There are multi-fruit trees with as many as 40 different fruit, but would it be possible to graft a vegetable onto a tree? Or maybe something in between, like grafting onto an apple tree a fruits in ...
4
votes
2answers
355 views

What do biologists mean when they use the term “biological distance”?

Here is its usage. "there is sufficient genetic control to make nonmetric traits useful in anthropological work, and such variables have successfully assigned individuals from distinct geographic ...
1
vote
2answers
92 views

Aligning multiple sequences in heterogeneous group

I have a list of ~200 DNA sequences, representing probably 50 different genomic regions but they're all mixed up. For example, if I have seq1, seq2.... seq10, ...
3
votes
1answer
87 views

Mutation Rate in Multicellular Eukaryotes

I always hear people saying that the mutation rate is around $10^{-6}$ or $10^{-7}$. I don't even know if this number is the mutation rate of genes or of a single nucleotides and I actually (almost) ...
6
votes
2answers
183 views

Hamilton's inclusive fitness approach

The underlying intuition of Hamilton's model of inclusive fitness is that we should study social behaviors from the point of view of actors -- rather than the recipients. To build his model, Hamilton ...
10
votes
3answers
3k views

Why did humans become bipedal?

Somewhere in evolutionary history homo started walking upright and became bipedal. You hear these hypotheses that, by walking upright, they could see better across the grassy savannas to escape ...
2
votes
2answers
158 views

What is the effect of persistent hypothermia on cardiac performance?

I define persistent hypothermia in this thread about the mechanisms of persistent hypothermia. The Graph of Katzung et al. in Pharmacology about Heart Failure: I am thinking which parts here are ...
3
votes
2answers
259 views

Is it possible to move your arms above your head when handcuffed in the back?

This move was seen in Pitch Black and i wonder if it is possible at all. Say you are handcuffed to a pole, hands in the back, and the pôle is a little higher than your head. You just want to do a ...
1
vote
1answer
80 views

Protocol for checking pipette calibrations using absorbance readings of a dye in solution?

I've been looking around the net looking for a nice protocol to validate micropipette calibrations using absorbance readings of a dye in solution. Does anyone have one they can share? I'd highly ...
1
vote
2answers
352 views

What is the importance of urea in mass spectrometry?

What is the importance of urea in mass spectrometry? We use 8M urea to FASP our proteins prior to mass spectrometry. What is the significance of using 8M urea? and how does it affect the proteins?
6
votes
1answer
505 views

What physics knowledge can be applied to biology of organisms and ecosystems?

In the wiki page of Biophysics: Biophysics spans all scales of biological organization, from the molecular scale to whole organisms and ecosystems. But after searching on the internet; the ...
3
votes
2answers
211 views

How do humans perceive time?

We can see length, and other physical quantities. We can perceive through our other senses like (temperature through thermoreceptors, weight through pressure receptors etc.). But how do we "sense" ...
3
votes
1answer
3k views

Does sample buffer require EDTA for protein separation on SDS PAGE?

In sample buffer preparation we add EDTA, but if SDS-PAGE is for protein then is it necessary to add EDTA in sample buffer? What is role of EDTA in sample buffer for protein separation for SDS-PAGE.
1
vote
0answers
37 views

How much does sleeping correlate with daily activity?

I'm a very lazy person. I spend most of my time in a chair, at a computer; I eat more than three meals a day. I don't do any sport, at all. What I want to know is: why do I need to sleep 8-12 hours ...
10
votes
3answers
211 views

Formation of Life

Originally, life evolved from non-living matter. Why is life only generated from other life nowadays, and why doesn't it evolve from inanimate matter, like it did originally billions of years ago, ...
7
votes
1answer
1k views

Are pulp cells (in oranges) normal plant cells?

Does a pulp cell contain all the elements that a 'normal' plant cell contains? I've searched for an hour to find more information about this but couldn't find anything useful. Is the pulp cell the ...
1
vote
2answers
115 views

Kinetic binding / unbinding constants of protein + mRNA ⇌ mRNP

I wish to find an order of magnitude for the binding/unbinding constants of mRNA and RNA-binding proteins. Suppose molecules A and B reversibly associate to give the complex C. Assuming the diffusion ...
2
votes
1answer
98 views

Species Identification (Insect)

I found this insect today in front of my room. I'm just curious to know what kind of insect it is? And, Is it poisonous? Location: India Thanks.
13
votes
2answers
839 views

Do electromagnetic waves outside the visible spectrum have any role in photosynthesis?

Does photosynthesis occur only in the visible spectrum? If there is a way to completely remove all other electromagnetic bands from the sunlight, including infrared (IR), will photosynthesis continue ...
3
votes
1answer
103 views

How would real-time blood glucose monitoring work?

Is it possible to perform real-time blood glucose monitoring using a wearable non-invasive device (similar to a fitness band measuring heart rate)? I'm aware that there are some devices in the market ...
28
votes
1answer
6k views

How many mosquitoes would it take to “drain” enough blood to put a person into shock?

I'm just curious, how many mosquito "bites" (mosquitoes which have removed blood from a person) would it take to remove enough blood to put a person into shock? (Putting aside all reasons why it ...
2
votes
1answer
89 views

How does the genetic material differ between dizygotic twins and ordinary siblings?

I am going to give a rough presentation on twin studies. The terms heritability and concordance are included already, but I struggle with understanding the difference of the genetic material of ...
1
vote
1answer
45 views

What controls Fructose regulation in plants?

Sugars are found ubiquitously in plants and are regulated. For sucrose it's pretty straightforward - it's basically kept at a low ish level, and put into storage or other intermediate compounds. ...
7
votes
1answer
87 views

Hamilton's derivation of direct fitness from his 1970 paper

In his 1970 paper "Selfish and Spiteful Behaviour in an Evolutionary Model", Hamilton uses Price's equation to derive his well-known rule $rb -c >0$. My question is about one of the steps in his ...
0
votes
1answer
157 views

What is the second phase of photosynthesis?

I really want to know what the second phase of photosynthesis (in the dark) is. I have a fair understanding of the first cycle where molecular oxygen is generated under the influence of light, but I ...
2
votes
1answer
76 views

How does steroid dependence occur?

I have seen on the internet that prolonged steriod treatment can result in the development of steroid drug tolerance leading to decreased hormone secretion. In turn this may lead to drug dependence, ...
12
votes
3answers
1k views

How many cells does the smallest animal have?

Note: question rewritten to prevent misunderstanding and make it more answerable I know that some small animals like C. elegans display surprising sophistication with a very small number of cells. ...
1
vote
1answer
202 views

C1q attachment to antibodies

After reading about complement pathway and the complement components, I was wondering, does the C1q component attach to the Fab fragment or to the Fc fragment? The pictures in Janeway's Immunobiology ...
0
votes
1answer
277 views

Can cfDNA testing distinguish results in the case of twins?

A fetus can now be screened for some of the more common genetic diseases and its sex determined from just a whole blood sample from the pregnant mother. Fetal DNA is abundant enough in the systemic ...
1
vote
1answer
63 views

What term describes insects that must eat protein to reproduce?

I know there is a specific term for insects that need to consume protein to produce viable eggs, as well as a term for those insects that don't need to consume protein to produce viable eggs.
3
votes
1answer
4k views

Why can blood group O be given to all blood groups?

Blood group O has antibodies against antigens A and B. Blood group A has A antigen. If someone with blood group A receives donor blood with group O, then anti-A antibodies in the donor blood should ...
3
votes
1answer
269 views

How fallible are DNA paternity tests?

Is it possible to get either a false positive or a false negative from a DNA paternity test and what would be the likely mechanisms behind this? For example, is it possible that a father's DNA could ...
0
votes
1answer
1k views

When do the spindle fibers attach to the chromosome

At what phase does this occur in mitosis (or even meiosis); some text books say prophase while others say metaphase.
5
votes
1answer
100 views

Is probability for double crossing over included in distance cM? [task]

We got this task: There are 3 genes (acb) on one chromosome (linked inheritance). Distance a-c = 12cM, a-b=16cM. Probability for double crossing-over (CO) is 0,6%. Find ratio of genotypes of ...

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