5
votes
3answers
506 views

Why has grey hair evolved?

A vast majority of humans get at least some grey hair as they age. As far as I know this applies to both genders and all races. Presumably this means that at least some grey haired humans have ...
2
votes
2answers
76 views

Why isn't Bubonic Plague as virulent as it once was?

Although I am admittedly not anywhere near an expert on any topic, I still have a hard time understanding how Black Death and Bubonic plague are one in the same. Since plague still exists, with news ...
3
votes
1answer
5k views

What is the ratio of breathing rate to heart rate?

Breathing rate and heart rate are directly connected. This is because the heart is connected to the lungs via the pulmonary artery. I first thought that breathing rate would be half of the heart rate ...
6
votes
2answers
156 views

(How) can a pink grasshopper exist?

I saw this foto on Reddit recently: Is this possible? How can a grasshopper become like this? Is this just natural genetic mutation?
4
votes
1answer
92 views

multiple HIV infection in same T cell

I was wondering can multiple HIV virus infecting same T cell ? Coz in flu virus they have SA to cleave of those sialic acid residue preventing re-infection of the same cell by other viruses to ...
1
vote
1answer
142 views

Regarding the difference between cDNA library and RNA sequencing (Biochem. technique)

I was wondering why establishment of cDNA library required the step of reverse transcription (i.e. turning the sequence into DNA) why not directly using the extracted RNA for sequencing and converting ...
1
vote
1answer
135 views

How to estimate the DNA density in human sperm head? [closed]

I have got an estimate of sperm head volume from internet.Like consider it as a disk of order 4-5µm. Now I wanted to find the DNA density in the sperm head. How to find that?
1
vote
1answer
35 views

What triggers the release of gonadotrophin-releasing hormone with the onset of puberty?

I am interested to know the process of development of puberty. During puberty, when boys/girls reache 12-14 (puberty) years of their age, their hypothalamus releases gonadotropin releasing hormone ...
6
votes
1answer
692 views

Alfred Jost's rabbit experiment: how did he actually do it?

I was watching a Crash Course on Biology YouTube video by Hank Green: Great Glands - Your Endocrine System. Hank humorously describes a sex determination experiment by Alfred Jost as follows ...
4
votes
2answers
113 views

Is the water transpired by plants pure H₂O, or does it contain trace minerals?

I'm considering the idea of drinking water that I trap from what is transpired by trees. Interestingly, is this water a fairly (or maybe even extraordinarily) pure form of H₂O, a remarkably pure ...
3
votes
2answers
77 views

Why do pine stands exist?

I live in the midwestern United States. I cycle to work, sometimes on heavily wooded roads, and I can't help but notice that in most places within the surrounding deciduous forests Pine and evergreen ...
4
votes
1answer
262 views

What is this beetle?

During a pit stop on the road from North Carolina to New York (somewhere in Delaware) I found the following (dead) insect in the car park: As you can see from the quarter next to it (25 mm ...
1
vote
1answer
133 views

What is the name of this big plant with a purple trunk and green to purple berries? [duplicate]

I have photographed the following plant in our garden in Pittsburgh, PA. Do you know the name of the plant?
1
vote
1answer
84 views

How do Type I restriction enzymes work?

According to NCBI, type I REases have a specific target sequence but randomly make cuts at sites far from the target sequence. How does the restriction enzyme travel from the target sequence to the ...
5
votes
1answer
203 views

Is oxidative phosphorylation less efficient in gram positive bacteria?

Gram negative bacteria perform oxidative phosphorylation in their periplasmic regions, between the inner and outer membrane where a proton gradient is maintained and used by the ATP synthase to make ...
4
votes
1answer
407 views

Null distribution of Blomberg's K

I've noticed different functions in different R libraries have different ways of assessing significance for Blomberg's K. For instance, picante's phylosignal looks at a distribution of PIC variance ...
11
votes
1answer
262 views

When did CRISPR/Cas9 evolve and what is the likelihood that a superior system for live cell genome editing has already evolved on earth since then?

I've read that CRISPR/Cas9 is currently being implemented and tested for its ability to edit genomes in live cells, and that it is supplanting other genome editing tools in labs, such as TALENs and ...
5
votes
2answers
304 views
7
votes
1answer
389 views

What are the atmospheric requirements for large dinosaurs?

What are the atmospheric requirements for large dinosaurs? and are the atmospheric constituents for supporting large dinosaurs any different from the atmosphere today?
3
votes
3answers
75 views

sex limited genome transmission

In general, for dioecious species, a large portion of the genome passed from parents to offspring of both sexes - in mammals the X-chromosomes and autosomes are passed from a mother to both daughters ...
4
votes
1answer
344 views

What is a protective epitope?

What is a protective epitope? An epitope is basically a part of antigen. So does it mean that when the epitope combines with an antibody, it helps in the functioning of the antibody instead of going ...
2
votes
0answers
52 views

How can oxygen production during photosynthesis be measured? [duplicate]

I'm curious how people measure quantitatively photosynthetic rate in labs. I've seen many qualitative examples with direct observations of bubbles forming in water due to photosynthetic output of ...
2
votes
1answer
55 views

Is severe but short-term pain worse than moderate but prolonged pain for the body?

I'm wondering about the effects of different durations and intensities of pain on the body. So the two can be compared, let's say that the cause of pain is the same in both cases, but in one the ...
2
votes
1answer
69 views

What can myelination tell you about the evolution of sensory receptors?

I am reading Avi Chaudhuri's Fundamentals of Sensory Perception and wondering if the information given about the somatosensory system could tell us anything about the way it evolved. It seems (at ...
1
vote
1answer
35 views

Pollinator mating system in orchids

I came across three terms in an article on pseudocopulation. However I don't quite understand what it means. They are: 1) solitary and haplodiploid 2) social and haplodiploid 3) diploid These ...
3
votes
0answers
44 views

What does the term 'epitope mapping' mean? [closed]

Epitope mapping means identifying the binding site of antibodies on the target antigen. This means that the site to be identified is part of the antigen and not antibody, am I right?
2
votes
2answers
62 views

Where I can find information about the study of animal vision?

I read a lot of articles on the internet about how dog see the the world. But I can't find the source of these study. I want to know how did scientist setup the experiment to find out animal vision. I ...
4
votes
3answers
1k views

What is the mechanism of oxygen uptake in E. coli?

How does E. coli uptake oxygen? Most of the literature I found is concerned with response to oxygen level supplied in the medium, as opposed to how much is actually transported inside. Can they shut ...
9
votes
1answer
158 views

What are the effects of sleep deprivation?

Having recently pulled an "all-nighter" while trying to fix a fatal bug in our release code, I started thinking of any health risks that I might have. What are the adverse effects of staying up for ...
1
vote
1answer
257 views

Does the fossil record disprove Evolution? [closed]

It is said by people opposed to Evolution, that the fossil record contradicts and disproves it. They say all the animals suddenly appeared, exploded everywhere, were fully formed, had no transitions, ...
8
votes
1answer
500 views

What happens to bones that do not heal?

I would like to know the steps the body takes to heal a broken bone and what happens if it cannot heal properly. I am not looking for advice or explanations on resting and not doing activity, I am ...
1
vote
1answer
511 views

What is the fastest growing bacterium?

E. coli has a generation time of about 20 min, and a single CFU will generate a colony a few millimeters in diameter after 16 hours of incubation. Is this the upper limit? How much faster can ...
1
vote
1answer
140 views

Duplicity Vs. Singularity of Mammals Organs [closed]

Are there known evolutionary reasons why mammals contain 2 of some organs (such as lungs and kidneys) and only 1 of some (such as liver)?
3
votes
1answer
132 views

Is there a difference between drinking water straight from the tap compared to leaving it to sit?

An idle question - if a glass if filled from the tap and consumed immediately, it contains some dissolved oxygen from the physical process of moving through the pipes & tap. If left out ...
2
votes
2answers
157 views

How do I perform recurring pattern mining or regular expressions of nucleotide sequences?

I am interested in performing nucleotide sequence pattern-mining (regular expressions) which is 12 characters (sequences) in length from a dataset. Is that possible to script using MATLAB?
3
votes
1answer
88 views

Do bees make honey from fallen fruit?

I know bees make honey from nectar, and I know they drink the juice of fallen fruit, but do they actually make honey from fruit, or do they only eat from it for themselves?
5
votes
2answers
2k views

Do flies actually take off backwards?

I've been told that flies take off backwards, but I haven't really been able to prove it to myself. The closest I've gotten was noticing that they fly into window glass back-first, with their heads ...
0
votes
1answer
142 views

Would it be possible to force the pineal gland to release dimethyltryptamine on command?

To my knowledge, the pineal gland is responsible for the release of dimethyltryptamine (DMT) upon death. Would it be possible to force the pineal gland to release this DMT while still living?
3
votes
2answers
72 views

What is an Ihh-/- mouse?

This one is too basic question: I just came across $Ihh^{-/-}\ $ mouse. Is that means this mouse devoid of that gene Ihh. What is this sign called and are there other such representations?
10
votes
3answers
105 views

What is the smallest scale at which blood vessels, nerves and other structures are deterministic?

Super simple question, but I can't find the answer on the Internet (and I'm in a foreign country so the library is not English.) As the title says, what is the smallest scale at which blood vessels, ...
3
votes
0answers
298 views

Hoechst red and blue spectra - what does the red emission tell us?

I understand that the blue spectrum is emitted when Hoechst 33342 binds to nuclear DNA. But what exactly is the red spectrum telling us? I read that the red spectrum can be indicative of apoptosis, ...
1
vote
1answer
30 views

Do snail shells increase the number of rounds with age?

Do snail shells increase the number of rounds with snail age?
2
votes
1answer
214 views

Does a woman's G-spot actually exist? [closed]

Does a woman's G-spot actually exist? Are there any research studies? Links: G-spot (Gräfenberg spot) at Wikipedia U.S. gynaecologist says he has found the G-spot
3
votes
1answer
59 views

What class of histone deacetylase (HDAC) inhibitor is sodium valproate (VPA)?

VPA is a known HDAC inhibitor. But I cannot find what class it is. What class is it? And is there any method of finding an answer better than floundering with Google?
1
vote
1answer
41 views

Why some muscles have more tendons than others?

Very interesting examples to me are Trapezius or Latissimus - they both have places with more tendons than muscles. Taking into account that now they contract weaker and slower with all these tendons, ...
5
votes
1answer
81 views

Do human neurons in a petri dish do different things from chimpanzee neurons

I want to know if qualitative experiments have been done growing chimpanzee neurons and human neurons in vitro and have any differences emerged, such as the amount of connections per neuron or ...
1
vote
1answer
69 views

Gastro-intestinal physiology reference

I am a physicist but I have always wanted to understand how my digestion takes place in as much detail as possible. I have no idea about books or reference on the subject of Gastro-intestinal and ...
2
votes
1answer
48 views

What are the minimal chemical requirements for a food which we all can eat? [closed]

I've been puzzled by the following though experiment for the past few days: I want to make my own food from scratch, but I do not know where to start from. I want to be 100% sure that what I eat will ...
2
votes
1answer
160 views

What is the functional significance of the difference in cardiolipin/cholesterol ratio in different membranes?

I have read somewhere that the plasma membrane has little cardiolipin but excess cholesterol whereas the inner mitochondrial membrane is rich in cardiolipin and has little cholesterol.I just wanted to ...
2
votes
1answer
100 views

Pectinase Enzyme Assay

I am working on pectinase enzyme assay. I incubated 900 ul of substrate for 10 minutes in the water bath, followed by adding 2ml of DNSA reagent, then 100ul of enzyme extract added finally i read the ...

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