0
votes
1answer
52 views

Why is Aorta sometimes called Compression chamber?

I find this statement that Aorta is called Compression Chamber in my study materials. Aorta can it keeps blood flowing it can accumulate potential energy for bumping and compression However, why ...
2
votes
2answers
227 views

Do humans have a “dominant” neurotransmitter system/sensitivity within their brain?

I've recently heard a podcast, in which Dr. Helen Fisher suggests that there are "4 broad personality types", and each one is associated with a particular neurotransmitter: The corresponding ...
6
votes
1answer
411 views

Which of the cell types commonly found in mammals has the greatest number of mitochondria?

This is basically a fun question, inspired by this answer on scifi.se. So, which cell type will have the greatest number of mitochondria? Obviously, I am talking about wild type, healthy individuals ...
2
votes
3answers
297 views

What do you see if you look at your own retina with the same eye? (optical feedback)

When you record a video while pointing the viewfinder towards the screen showing a live preview you create optical feedback: video example. An anoalogous effect occurs when you turn your microphone ...
0
votes
1answer
123 views

Regional circulation and Cardiac output? [closed]

I am reading my study materials and think what is the systemic POV here Regional circulation Blood flow within the tissue/organs based on the functional demands of the tissue. E.g. The ...
4
votes
3answers
658 views

How many (taxonomic) families are there?

Approximately, how many families have been identified? I've often often come across figures for the total number of species on Earth. Recently, I found myself wondering about the encompassing ranks ...
0
votes
1answer
16 views

How does Mupirocin affect in staphylococcal infection?

I found this sentence confusing Transitor carriers of staphylococcal infections 70% because of mupirocin i/n. Mupirocin is drug which affects some way. I am not ...
1
vote
1answer
35 views

Staphylococcus AG structure?

I found this statement in my study materials in the section of Staphylococcus The AG structure: protein AG (species specific); polysaccharide AG (serotype specific). I know what is ...
0
votes
0answers
68 views

Identification of a mysterious lifeform, what is this? [duplicate]

For the third time in a row, I found a mysterious life-form inside my house. I live in the Netherlands in the Eindhoven region, in a city called Oss near a forest area. Before I set it free outside, I ...
1
vote
1answer
303 views

Birds and Dinosaurs

This came up in an argument with some friends. I know that birds are direct descendants of dinosaurs, shown pretty clearly through the fossil record. However, is it proper to say that birds are ...
0
votes
1answer
36 views

Characteristics of radius of blood vessel

Which properties do determine the radius of blood vessel? I have these thoughts distension, elasticity, contractility and cross-sectional area of the walls. Is there any other properties?
2
votes
1answer
418 views

Elution of biotinylated RNA

I am using Neutravidin Agarose beads to isolate biotinylated RNA. The thing is, in the manual it says to use 8M Guanidine-HCl, pH 1.5 for elution biotinylated molecules. As far as I know it is a very ...
3
votes
1answer
759 views

Death by exsanguination not painful?

Several places on the internet seem to purport that animal sacrifice is painless because exsanguination causes no pain. That sounds unscientific to me and an attempt to appease culture than than using ...
1
vote
1answer
26 views

To understand synthesis of e-NOS and n-NOS with respect to Ca and calmodulin

I found this sentence in my notes interesting E-NOS and n-NOS are Ca-calmodulin dependent ferments. They are synthesized in small concentration as a response to physiological signals which ...
6
votes
1answer
226 views

What percentage of the (additive or not) genetic variance is explained by the 'n'- most important loci?

Standard models in population genetics look up at the evolution of few loci which impact fitness. The variance in fitness is determined by the genetic variance and the environmental variance (and the ...
0
votes
2answers
61 views

To understand Second messenger signalling in I/c and E/c

I found this picture in my study materials. I think it is too schematic and ignores the big pictures. I think the thing connected to the hormone is receptor. The second messanger is then connected ...
1
vote
0answers
95 views

Osmosis - occurring in both ways? [closed]

So I did a prac to identify the osmotic potential of potato tuber cells. There were 5 test tubes with different concentrations of sucrose (0M,0.25M,0.5M,0.75M,1M); a small slice of potato was placed ...
1
vote
0answers
63 views

How many blood types are there? [duplicate]

In total how many blood types are there? And why do people normally know only 8 of them? (A+, B+ , AB+ and O+ and Rh- counterparts)
3
votes
2answers
300 views

Correlation between muscle size and absolute strength

Is there a linear connection between muscle size and the power it can produce? If not, why? And what is the true correlation if any, can it be described with an appropriate function? What other ...
0
votes
1answer
183 views

Can you approximate Cardiac Output by Ohm's law?

I found this sentence from my notes which I cannot understand PR < CO, CO $\uparrow$, PR > CO $\downarrow$ where ...
0
votes
2answers
383 views

How to design an experiment with scent triggered memory recall in humans?

I've recently learned that scents can trigger memory recall in humans, and am thinking about setting up an experiment where I would attempt to induce memory recall through exposure to scents. In ...
1
vote
1answer
112 views

Gene distance and Recombination Frequency: Mechanism

Why is the recombination frequency higher if the genes are farther apart?
3
votes
1answer
88 views

Is a single x-ray photon capable of doing enough damage to the DNA of a cell to kill that cell? [closed]

Ionizing radiation is damaging to DNA, but is there such a thing as a safe dose below which no DNA damage could occur? I'm not asking about a minimum safe dose overall, just whether or not there's an ...
1
vote
1answer
95 views

In vitro transcription, contamination problem

I am using a RNA which is in vitro transcripted before I started my project. It turned out it is not prepared properly and has DNA contamination. Instead of perform the in vitro transcription again, ...
3
votes
1answer
94 views

Why do hummingbirds build nests with live ferns instead of dead materials?

Hummingbirds prefer to build their nests with spore-bearing ferns, and mosses. This is helpful for the reproduction of the ferns, which are then better able to spread their seeds. But how is this ...
1
vote
1answer
135 views

Calculating photosynthetic efficiency

While calculating photosynthetic efficiency, do we take into account the Gross Primary Production or the Net Primary Production ?
4
votes
0answers
188 views

How do duplicate brain regions (ex: left/right amygdaloid body) operate together?

I frequently hear talk about parts of the brain like "Amygdala" or "Hypothalamus", so I looked them up in an app called "essential anatomy". What I see is that there's mirror symmetry, and most of ...
1
vote
1answer
126 views

Is end-systolic volume (ESV) the same as residual volume?

I am reading this site and my study materials. The end-systolic volume (ESV), 50-60 ml, is the volume of blood found in ventricles after systole and contraction of ventricles. I think ESV is the same ...
3
votes
3answers
91 views

Can 'hardware' thermalization explain memory decay?

Often we are able to memorize very precise bits of information (exact addresses, birthdays of inlaws, number of dirty socks under the bed), but over time our recollection tends to become fuzzy. We no ...
6
votes
2answers
133 views

What type of force holds my body rigid & doesn't make it collapse?

My query is that as atoms & its molecules have inter & intra molecular forces,like that only what type of force keeps the cells bonded to each other & prevent it from collapsing ever ...
4
votes
2answers
201 views

Can diploidy evolve in absence of sexual reproduction?

Theoretical question Can diploidy (or polyploidy) evolve from a haploid lineage in the absence of sexual reproduction ? For what theoretical reason? How can such evolution take place? Empirical ...
-1
votes
1answer
90 views

Can nature create codes and specified complexity? [closed]

Is there an example of nature creating codes or specified complexity? It is said by Creationists that codes can only come from minds, and since DNA has a code, it was created by a mind. Is this true? ...
0
votes
1answer
49 views

An over-simplified model of cell division and its relation to stem cells

I am a mathematician, and I decided to try to model cell division with math and see what conclusions came out of it. I had some questions concerning stem cells that came up in the model. In an ...
1
vote
1answer
57 views

RNA integrity and RNA fragmentation

After RNA isolation and before following experiments, I know that RNA quality so called RNA integrity is so important. So why there is a RNA fragmentation kit? Do we need RNA intact or fragmented? ...
1
vote
1answer
90 views

Dilution question about RNA

I have a basic and probably silly question. I am isolating RNA with TRIzol. I have performed the basic steps and dissolved the pellet in 50 uL water. I ve measured the concentration and it was 3313 ...
0
votes
2answers
535 views

Can you answer Ray Comfort's question on Biological Evolution? [closed]

https://www.youtube.com/watch?v=U0u3-2CGOMQ There's this video on Youtube about biological Evolution that has gone viral. I'll paste it above for your convenience. To cut to the chase, Ray Comfort ...
0
votes
1answer
56 views

Normal position of Electrical axis only in the III lead?

I found this sentence in my notes which is not exact enough: Electrical axes Excitatory processes have definite direction and magnitude and could therefore be represented as vectors. At ...
6
votes
2answers
658 views

Why aren't we ambidextrous?

It seems so simple that if my brain can tell my right hand to do something, then it should be able to tell equally well to the left ? This seems like a pretty major evolutionary advantage. Why haven't ...
0
votes
1answer
96 views

How does a smoker's pleasure work?

I smoke. For some reason, I've always had this idea that the pleasure of smoking works more or less like this: from the lungs, the nicotine reaches the blood, with which it travels to the brain, and ...
1
vote
1answer
81 views

Physiology of skin and leather: why do salt borders occur?

I discussed a leather store about the white border aka salt border on leather shoes. They said that it is due to inner features of leather and you could try to add some fat/cream to push it back ...
-1
votes
1answer
76 views

Can a certain part of human dna can be replaced with other animals dna?

Human DNA consists of adenine, thymine, guanine and cytosine. Can thymine of other animal can be placed with humans thymine?
0
votes
1answer
74 views

Difficulty in developing certain vaccines

I have a college level background in Biology, say at the level of Campbell. I am very curious to know why it's extremely difficult to develop vaccines for certain diseases. Two cases which I am really ...
16
votes
3answers
2k views

Are humans the only animal that requires “clean water”?

I've seen a number of animals - dogs, cats, squirrels, ducks and geese, etc drink from puddles, some of them were muddy, others had green flora growing under water. Same goes for lakes and rivers. A ...
1
vote
2answers
63 views

Referencing the homologous chromosomes

There exist a co-ordinate system from chromosomes like "12p11.3". In this system, first integer range from 1 to 23 i.e it takes homologous chromosomes as a pair. If we want to distinguish among ...
4
votes
1answer
136 views

What constitutes the determination of a normal blood glucose level?

Several on-line resources (e.g. MedlinePlus) suggest: Normal range for non-diabetic people who are fasting should range between: 70 and 100 milligrams per deciliter (mg/dL) Non-diabetic people who ...
1
vote
1answer
2k views
3
votes
1answer
82 views

What's the use of RNA editing in kinetoplast?

The genes of the mitochondrion (kinetoplast) of some Kinetoplastida - e.g. Trypanosoma brucei, the parasite which causes African sleeping sickness - are "encoded" in a way that the pre mRNA requiries ...
1
vote
1answer
67 views

Why PPD test in patients without M.tuberculosis often slightly positive?

I got this question which I interpret as Why PPD test in patients without M. tuberculosis often have slightly positive PPD reaction i.e., a lifelong slightly positive skin test reaction? because ...
2
votes
3answers
136 views

Why HIV patients have greater virulence of M.tuberculosis?

I am reading Murray Microbiology book. Some facts M. tuberculosis is an intracellular pathogen. At the time of exposure, M. tuberculosis enters the respiratory airways and infectious particles ...
1
vote
1answer
90 views

Transcribing DNA to mRNA with introns

I have a problem in my bioinformatics class that I thought I was doing right, but someone else is getting a different answer. Here is the problem: Given the following DNA sequence, ...

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