7
votes
1answer
96 views

What are the costs associated with carrying lots of genetic material

What are the costs (if any) associated with carrying lots of genetic material? energy for copying? raw material for copying? space in the cell? Maintenance cost (matter and energy)? time to copy is ...
2
votes
1answer
602 views

Why do three nucleotides code for one amino acid? Why not 5 nucleotides? [duplicate]

We all know why there are 3-base codons, and why there aren't any 2-base codons. But why is there not a 4-base a 5-base codon?
5
votes
3answers
438 views

Evolution: How could all useful traits evolve simultaneously?

I have a basic question about evolution, for which I never found an answer. I understand how evolution works if we focus on one specific organ or trait. With each generation, some organism is more ...
0
votes
0answers
32 views

Simultaneous depolarisation of Sinus Node and AV node as extrasystole in myocardial infarction patient

Assume you have a patient 68 years old with previous myocardial infarction (Actually patient 201 in MIT-BIT arrhythmia database). Assume that AV node depolarises strongly. However, at the same time, ...
2
votes
0answers
79 views

Why does IUCN classify pistachio as a “Near Threatened” species?

When reading the Wikipedia entry on pistachio, I noticed that IUCN has classified the plant under "Near Threatened". On looking up its entry at IUCN, I see that its population is trending downwards, ...
1
vote
1answer
103 views

Troubleshooting for Agarose Gel Electrophoresis

SI ran my 2% agarose gel on constant voltage (100 V). For a few times it worked at CV but, after a week or so the machine would automatically switch to constant current by itself. And this only ...
2
votes
1answer
52 views

Are there any fungi that can digest humic acids?

Humic acids are a complex group of organic substances, that are generally known to be hardly biodegradable. Fungi as agroup are known for breaking down complex organic matter like cellulose or lignin. ...
0
votes
0answers
14 views

Calling for Pressure pictures about Right and Left atrium

I am trying to understand the partially patent foramen ovale in patients with right-side heart failure. I am interested how the pressure in right and left atrium change in normal case in abnormal ...
0
votes
2answers
50 views

Is Sinus node conduction necessary for heart beating?

Assume a patient with previous cardial infaction which SA node not possible to activate action potential anymore. However, SA trying to beat unsuccessfully repeatedly waisting energy. Therefore, I ...
0
votes
0answers
20 views

Laser surgery to stop damaged Sinus node from beating

I am trying to find any publication about laser surgery to stop the damaged sinus node which cannot anymore beat. I could only find publications which modifies SA node function. I am not sure if it ...
1
vote
1answer
32 views

Usage of the taxonomic classification “Pinnipedia”

According to ITIS the classification Pinnipedia is invalid, and it is proposed to rather use Caniformia. The later group however includes a range of terrestrial animals as opposed to the pinnipeds ...
4
votes
1answer
112 views

Why mosquito bite is confined to a certain shape?

I think this problem should be asked in a physiology forum rather than biology@ stackex but I'll give it a try. So my question is simple - why a mosquito bite is usually confined to a certain shape ...
3
votes
1answer
53 views

relative-rate of evolution

I am supposed to calculate the relative rate of evolution of two sequences (human and sheep) with a chicken serving as the outgroup. The sequences are pretty long, so I will just create a short ...
0
votes
1answer
23 views

Do trees have no set lifespan and “quite”immortal?

Many trees survive centuries and die only in disasters like storms and lightnings or infections. So do they have no set life span? Are they exceptionally resistant to genetic mutations and have very ...
9
votes
1answer
272 views

Did the eugenics program in Nazi Germany have a measurable effect? [closed]

Did the killing or sterilisation of people considered as living a "life unworthy of life" in Nazi Germany have any measurable effect on the "average health" of Germany? Is there any statistical ...
1
vote
0answers
60 views

What is the name of systemic tension of muscles?

I meat a overtrained friend (25 years old) who cannot rest. He has all muscles and most of the skin very tense. He is practising regularly in gym and sleep badly. He moves like a stick figure and has ...
3
votes
1answer
41 views

Why are many anti-malaria drugs gap junction antagonists?

Why are many anti-malaria drugs gap junction antagonists? My professor recently just mentioned that many of the anti-malaria drugs block gap junctions. i am wondering if this blocking is important ...
9
votes
3answers
247 views

Book recommendation on population/evolutionary genetics?

I have recently been involved in collaborations that require me to model the population genetics of eukaryotic populations. I fear I may either be "re-inventing the wheel" or making conceptual ...
1
vote
2answers
165 views

Does Science Say That We Should Die? [duplicate]

Excluding situations where you die from accidents, the main reason for death is -generaly- diseases. And usually it is about an organ which becomes "tired" after many years. These results are all ...
1
vote
2answers
74 views

How the lungs clear themselves?

Looking at my computer's fan I can say that a lot of dust is collected on it not less dust should be collected in the lungs, not to mention some inhaled parts of food. How the lungs clear themselves ...
1
vote
1answer
102 views

What happens when seeds are refrigerated before planting?

My son is doing a science research project at school, and he's chosen to research what happens when seeds are refrigerated before planting. I cannot provide any information in regards to background ...
1
vote
0answers
24 views

Which disorders are fully concordant?

I work in neuroscience, mostly Alzheimer's disease (AD), with some work in autism spectrum disorder (ASD). The work is in gene regulation and epigenomics. I'm familiar with monozygotic twin (MZ) ...
3
votes
2answers
90 views

Heterozygosity under genetic drift

The wright-Fisher model of genetic drift is: $$p_{ij} = \binom{2N}{j}\left(\frac{i}{2N}\right)^j \left(1- \frac{i}{2N}\right)^{2N-j} $$ ,where $\binom{2N}{j}$ is a binomial coefficient. From this ...
3
votes
1answer
88 views

How does GC-content evolve?

Background GC-content refers to the frequency of base pairs that are either C or G in the genome, or in other words the number of GC base pairs divided by the addition of the number of GC base pairs ...
6
votes
3answers
366 views

Why are there ecosystems?

Why would things self-organize in such a manner? I'm a mathematician and I have no baggage in ecology or biology. If the question is too broad maybe someone can point me to formal sources where this ...
2
votes
1answer
78 views

Are cell lines potentially dangerous?

More specifically, if a human subject was exposed to, say, a human cancerous cell line (via intravenous injection or through an open wound, for example), is it possible that they would develop any ...
6
votes
2answers
129 views

Why did women historically have such a high mortality rate during birth?

Historically women had a relatively high chance of dying while giving birth. At first thought it seems to me that this would be a disadvantage for the species for the obvious reason that a dead ...
1
vote
0answers
32 views

Can a tree survive if someone cuts all buds?

My thought was to cut all buds of a deciduous tree at spring and see if it can survive a year and develop new buds and leaves next spring. Assuming the tree is already grown and not a sapling. If the ...
2
votes
1answer
50 views

Why doesn't the sperm die if there is citric acid and acid phosphatases in the semen?

While studying I read that sperm needs alkaline medium for its survival.But when I studied the composition of semen it revealed that semen contains citric acid which acts as a sperm nutrient along ...
3
votes
1answer
89 views

Can oil be used instead of water in preparing wet mounts for microscopy?

Is there a reason that oil (e.g., vegetable or clear mineral) is not used to make wet mounts in microscopy? I am not referring to oil immersion technique but substituting oil for water in wet mounts ...
4
votes
2answers
143 views

Why isn't the phosphoglycerate kinase reaction of the glycolysis pathway irreversible?

Step 7 of the glycolysis pathway is the conversion of 1,3-bisphosphoglycerate into 3-phosphoglycerate by the action of the enzyme phosphoglycerate kinase, resulting in the production of 2 ATP ...
4
votes
2answers
459 views

What makes teeth feel sticky after drinking Coca-Cola?

I asked some of my friends and we all agree that teeth feel funny after drinking Coca-Cola. Other similar soft drinks also cause this effect, but this one most noticeably. It's like teeth become ...
2
votes
0answers
24 views

coverage calculations approach for clipped reads [closed]

Experiment: deep sequencing for mutants in 700nt fragment. the fragment of dna was preamplified by primers flanking the fragment followed by hiseq. per base coverage was calculated by coverageBed -d ...
2
votes
2answers
54 views

Can protein precipitate out in alcohol during DNA extraction?

In common lab sessions to extract DNA from strawberry or cheek cells, will there be protein contaminating the DNA extract in alcohol? If so, how can we prevent protein from precipitating out of the ...
1
vote
1answer
43 views

Appropriate statistical test for a student lab?

I am a HS Bio teacher and doing a microevolution lab involving candy. Essentially students use four candy types and push them together until one cracks (Nat Sel). They also do simulations of ...
0
votes
1answer
33 views

Manifestations of open foramen ovale in adults

I read that foramen ovale opens in 30% of adults. I do not know how much of these openings can then close again. Probably, none. It is not pathogenic if no symptoms. It allows blood to enter from ...
2
votes
1answer
31 views

Protein Conformation Modeling

I'm interested in learning about computational modeling in biophysics. I have heard some amount about people modeling proteins as a network of ideal springs to examine things like conformation ...
3
votes
1answer
66 views

Do people with gout live longer?

Antioxidants reduce damage to tissue (by scavenging the free radicals) and thus may reduce ageing.It is known that Uric acid is a very good antioxidant. People with gout have excess accumulation of ...
0
votes
1answer
49 views

Possible Genotypes — Linked Genes

Please consider the following question: Genes A and B are located on the same chromosome. If two individuals with the genotype shown below are crossed, which genotype could be formed? Let / ...
5
votes
2answers
167 views

What is an irreversible reaction?

There are reactions with large Delta G negative values. Why these reactions are irreversible? As in: out of 10 steps of Glycolysis, 3 are irreversible steps. I need an explanation for why they are ...
7
votes
4answers
357 views

Do tall people have more cells?

Within a single species, how does the relative number of cells in the body relate to the relative size of the organism? Let's say we take two humans, one of them is 6 feet tall and the other one is 5 ...
-1
votes
1answer
47 views

What is this abbreviation CT in female reproductive system [closed]

I have this sentence in my notes Ovary is surrounded by tunica albuginea and the cortex keeps the primordial follicles. The medulla containing CT and blood vessels develop from mesonephros. I ...
1
vote
2answers
61 views

Why is the human body hair not uniformly colored?

Most of my body hair is black however my lip hair is light brown/blonde the rest of my beard region is black. Since hair color is genetic what causes this?
2
votes
1answer
85 views

How do nutrients get to the cells they need to get to?

I understand the basics of digestion. I know that nutrients get absorbed by the microvilli, enter the bloodstream and travel to the liver but after all that, what is the biological mechanism that ...
3
votes
3answers
219 views

The effect of pH on enzymes

I am currently studying biology and have a question. I know that as pH increases, enzyme activity increase until the enzyme's optimum pH is reached. However, I would like to know why as pH increases ...
1
vote
1answer
561 views

Why do different humans look different?

Although farmers appear to be able to tell their cows apart, cows look very much alike to me. And this similarity in appearance seems to be a general trail across the animal kingdom: one individual of ...
2
votes
1answer
62 views

How does gene expression work in an adult organism? Is everything encoded everywhere?

The color of a person's eyes are genetically predetermined. If I knew how and in which gene(s) colors are encoded, I could change these genes in the ovary and sperm and thus change the eye color of ...
0
votes
1answer
37 views

In what circumstances does a mammalian egg copy its DNA?

In the 2nd episode of the new Cosmos series, the host Neil deGrasse Tyson shows how the white-furred bear could have evolved (reasonable scientific speculation, of course). If you haven't seen that ...
1
vote
0answers
17 views

Propagation of tool use in primates?

There are several famous cases of great apes demonstrating a surprising degree of wherewithal in communication and tool use - even monkeys can learn some tool use from each other observationally, even ...
1
vote
0answers
19 views

phosphorous availability to mycorrhizae and parent plant, timing - paper search

I'm researching (for my work) phosphorous uptake in monocots to develop planting mixes for riparian planting. I recently saw a paper suggesting (the author lacked proof) that root zone mycorrhizae ...

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