2
votes
1answer
121 views

The concepts of relatedness - Hamilton's rule and kin selection

Here is a quotation from this wikipedia page The relatedness parameter (r) in Hamilton's rule was introduced in 1922 by Sewall Wright as a coefficient of relationship that gives the ...
4
votes
1answer
99 views

Need for proper air filter for bioreactor?

I am going to build a simple bioreactor for microalgae growth. I already have fluid filters pore size: 0.2um, diameter: 25mm https://nl.vwr.com/app/catalog/Product?article_number=514-4039 I wonder ...
3
votes
0answers
54 views

Nocioception (pain perception) in subcutaneous tissue

There seem to be no nocioceptors (pain and temperature sensitive nerve endings) in subcutaneous fat. there are nocioceptors and other receptors in veins running through fat, but these can be avoided. ...
2
votes
1answer
813 views

Transfer of antibodies in breast milk of humans

Why isn't the IgA secreted in breast milk digested due to proteases of the digestive system in the baby? Wikipedia says: The secretory component of sIgA protects the immunoglobulin from being ...
4
votes
2answers
285 views

What are the ESSs among hawks, doves, retaliators, bully and prober retaliators?

In his book "The Selfish Gene", Richard Dawkins says that retaliator emerges as an evolutionary stable strategy. But I think dove is also a kind of retaliator and so if dove increases, the hawks and ...
1
vote
1answer
471 views

Transfer of antibodies from mother to fetus

My questions: When does fetus begins to acquire antibodies from mother? Does it continue throughout the pregnancy? From Wikipedia: http://en.wikipedia.org/wiki/Passive_immunity This occurs around ...
3
votes
2answers
716 views

Microscope recommendation for an amateur?

I am a mathematics student looking for a hobby and this has come up as a potential hobby. Thus I am interested in buying a high-magnification microscope that is within the limits of my budget. My ...
4
votes
1answer
81 views

Large scale reverse transcription?

I need to make RNA:DNA duplexes. I can make 100 to 200 ug of mRNA through in vitro transcription, and I know how to use reverse transcription to make a cDNA library, but I have questions with this. ...
5
votes
1answer
339 views

What do the signs +/+ +/- mean in this image?

I don't understand what this graph is supposed to explain, especially what the signs +/+ or -/- mean. I just know it characterises some rats.
1
vote
2answers
82 views

Henrietta Lacks Cell Line - Immortality

I'm a newbie in biology and medicine. I understand that Henrietta Lacks provided the cells that formed the HeLa cell line with which much research has been done. Henrietta Lacks died of cancer. If we ...
3
votes
1answer
67 views

What makes drosophila eyes red? and is it stable?

I have Drosophila melanogaster which I am doing an eye pigmentation assay on in the future. To do this I will dissolve the heads, 10 of them removed from frozen whole flies, in acidified ethanol for ...
0
votes
1answer
784 views

Is cell membrane living

We say cell wall is dead but nobody says cell membrane is dead. Is cell membrane living or dead ? If it is not dead then why is it not included in protoplasm : Protoplasm is the living contents ...
5
votes
2answers
572 views

Can Escherichia coli survive on glucose and water alone?

I am novice to biochemistry and biology in general. I am reading Lehninger Principles of Biochemistry, and I found the following sentence at the beginning of the chapter on glycolysis: A bacterium ...
8
votes
1answer
9k views

how to close a severed artery/vein?

This is a medicine-related question that I've been wondering about. I've been watching medical lectures on YouTube regarding the human body and was wondering about how surgeons treat a severed artery ...
3
votes
1answer
128 views

Evolutionary Cell Structuring

I'm a total novice when it comes to biology, and I'm really just looking for an answer to a question that has been posed to me by people who deny evolution fervently. Evolution dictates that we've ...
1
vote
1answer
67 views

Criteria for the numbering of human chromosomes

What were the criteria devised for the numbering convention employed in human chromosomes? When was it fixed? Correct me if I am wrong; it appears that chromosome pairs 1 to 22 were originally ...
9
votes
4answers
2k views

How do trees lift water higher than 10 meters?

The atmosphere pressure is 10 meters of water (approx). This means that it is impossible to lift water higher than 10 meters with vacuum or сapillary action (on Earth, under normal conditions). There ...
3
votes
1answer
27 views

External tissues, connected to the body?

Some cancer tumors suppress themselves from spreading. When such tumors are removed by surgery, the metastasis process is accelerated. Isn't it possible to put such tumors into external device like ...
12
votes
3answers
1k views

In Japan, the official average body temperature is 36.0 °C. Why so different from that of Europe?

The Japanese Wikipedia states that the average human body temperature is 36.0 °C (here,"ヒト"). The statement references the data from the Japanese government. Actually all of my Japanese friends think ...
1
vote
1answer
147 views

Is fat distributed proportionally around the body?

One guide I have been using to tell me if I really am gaining a lot of weight is a ring around my 2nd last finger on my right hand, if I can slip it on and off without any resistance then I'm fine, ...
3
votes
1answer
436 views

Family tree for edible plants?

I am looking for a family tree for plants, particularly veg / herbs / fruit. Something similar to: If it could be slightly less technical than all the Latin ...
3
votes
2answers
137 views

How far into a pregnancy is it before visible signs of it is apparent and risk of physical trauma increases

I'm doing research for a series I'm writing. in it the main character is pregnant however goes off to fight a criminal organization who have been killing her friends and i want her appearance to show ...
3
votes
2answers
5k views

How does extracellular potassium ion concentration and calcium ion concentration affect the excitability of a cell?

When extracellular $K^+$ concentration increase by a certain amount, excitability of cells is higher because the resting potential shifts toward a higher equilibrium potential of $K^+$, therefore ...
3
votes
2answers
178 views

How does Humira work when injected into patients with rheumatoid arthritis?

OK, I have rheumatoid arthritis and I've been injecting Humira 2 times a month for the last 8 months. As far as I know rheumatoid arthritis is simply an immune system disorder which makes the immune ...
3
votes
1answer
55 views

Euthyrodism and goitre

I read in Tortora and Derrickson that goitre is associated with euthyrodism. How is that possible?
1
vote
1answer
24 views

Giving diuretics to insipidus patient

I read in Tortora and Derrickson that giving diuretics to diabetes insipidus patients may in fact alleviate the symptoms of the disease. How is this possible?
0
votes
1answer
48 views

Growth Hormone and diabetes

Growth hormone and insulin like growth factors are diabetogenic, so I assume that people with high growth hormone (say due to pituitary tumor) may be at high risk for diabetes. Has any correlation ...
8
votes
3answers
267 views

Does the Petri dish lid orientation on workbench affect aseptic technique?

When examining an incubated plate, it is rather clear that holding the plate in one hand and the lid in another is best for aseptic technique, or simply resting the lid on the plate as shown below. ...
6
votes
2answers
4k views

What determines if a gene is dominant or recessive?

Going back to my high school days we were taught about dominant and recessive genes. We were taught how to calculate the geneotype and pheneotype of potential offspring using a small table (forgotten ...
0
votes
1answer
66 views

Function of carapace

Majority of crustacean larvae have expanded carapace drawn out into processes as an adaptation for : a. Protection from enemies b. Planktonic habit The answer given is b but I think it should be ...
2
votes
1answer
259 views

Population Growth Rate Question?

A population of 600 birds faced a problem of biological magnification resulting in a large number of deaths reducing their population to 350. But 230 births also took place and 21 birds immigrated ...
1
vote
1answer
164 views

Effect of pH on life? Use buffer or HCl? How about lactic acid?

I'm trying to find the effect of pH on living things like E. coli and such. At first I thought of using a buffer solution which maintains its level of pH, but it's possible that the inactive ions of ...
4
votes
1answer
152 views

Function of papain in papaya

I know that papain is a proteolytic enzyme present in papaya. It is often used to tenderise meat. What is the function of papain in papaya? Is papain sweet? Does it function as an antibiotic?
3
votes
0answers
59 views

The Operation of tuning in the S1 layer of ventral model

According to my previous question in ventral Stream pathway and architecture, I want now to get a brief example about how the S1 layer is constructed. In other words, how all the simple units are ...
2
votes
2answers
96 views

Breakdown current for human body

If I am not mistaken, during exposure to electricity sources it is the magnitude of the current and not the voltage that kills the human body. If so, what is the order of magnitude of current that ...
1
vote
1answer
909 views

Is Zymase, A Complex of Enzymes? Which ones?

Some websites state that the enzyme zymase (which I understand to be a complex of several enzymes) is responsible for catalyzing glycolysis in order to produce pyruvate. On the other hand, some ...
6
votes
1answer
188 views

Whole genome amino acid composition tool?

I'm interested in a statistical tool to get bacterial codon usage at genomic level. Ideally, the tool should be flexible to analyse hundreds of bacterial genomes. I've looked in MeSH terms database ...
2
votes
1answer
51 views

Exotic Cell Shapes

As far as I know, plant cell shapes are a difficult thing to pin down. However plant cells have cell walls and so can be very rigid. However the only plant cells I've seen have been either block ...
2
votes
1answer
889 views

Lyonization and X-linked disorders?

Lyonization or X-chromosome inactivation is the conversion of all but one, X-chromosomes in Females into non-coding heterochromatin (i.e. deactivated) leading to the formation of one or more Barr ...
5
votes
1answer
315 views

Empirical evidence for species selection

Do we have any empirical evidence in favor of species (or lineage) selection? Do we know some cases that can only be explained (or seem to be only explained) by lineage selection? What are today the ...
1
vote
2answers
223 views

Question about production of CFTR protein

How do organelles such as ribosomes, ER, Golgi and vesicles produce CFTR protein and mucus?
4
votes
1answer
94 views

Which of Perutz et al's protein structures other than 3₁₀ helix were correct?

In 1950, Bragg, Kendrew and Perutz published "Polypeptide chain configurations in crystalline proteins" (open access) and were famously 'proved wrong' by Pauling, Corey and Branson the following year, ...
6
votes
4answers
134 views

How to measure bacterial content

I´m using water container placed on a radiator to humidify room air. Someone might argue that it is a perfect nest for bacteria. I have to put copper coins into the water to kill the bacteria. I ...
4
votes
1answer
64 views

How much can you learn about species variation from a skeleton?

I just read about the discovery of the 1.8-million-year-old human skull in Georgia, and how it suggests that early humans were all one species instead of distinct ones. Would an archaeologist ...
3
votes
1answer
219 views

Ventral stream pathway and architecture proposed by Poggio's group

Please can you give me a very brief explanation about all functions in the ventral stream architecture summarized in this figure: This figure is from Serre et al.'s A quantitative theory of ...
1
vote
2answers
31 views

What are examples of genes succesfully reproducing in ways that is in conflict with helping the individual creating offspring

Most of the time, our genes have common interests with our "self". We reproduce well if and only if our genes reproduce well. In some cases, like in bees, the haploid bees can survive better if they ...
4
votes
1answer
3k views

Isotropy of sarcomere bands in skeletal muscle cells

As seen under a polarization microscope, the A-Band in skeletal muscle fibres is so named because it is anisotropic in its refractive index which is a characteristic of orderly crystalline structure. ...
3
votes
2answers
121 views

Which hydroxyl from either the phosphate or the glycerol is taken during synthesis of a phospholipid head?

The oxygen anion in the phosphate group is likely to be bonded with a hydrogen cation and thus forming a hydroxyl. When the phosphate group is condensed with glycerol to make a phospholipid, is the ...
2
votes
1answer
88 views

Are there known 3- or 4-nucleotide RNA linkers with no RE sites?

Question is rather self-explanatory. I'm looking for a non-cleavable RNA sequence to act as an RNA linker. I mention 3- or 4-nucleotides only, but making such a sequence with 2 nucleotides is rather ...
2
votes
2answers
326 views

Do brain cells shrink during REM sleep or a lucid dream?

In this BBC news article a study shows that during sleep brain cells shrink to open up the gaps between neurons and allow fluid to wash the brain clean. But do the cells shrink and undergo the whole ...

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