1
vote
1answer
57 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 ...
12
votes
3answers
248 views

How do we know that dinosaurs were related to lizards and/or birds?

Do we clearly know what the living closest relative of the dinosaurs are? And connected to the first question, in scientific manner how do we know these relationship between extinct species and living ...
1
vote
2answers
74 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 ...
2
votes
0answers
117 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
0answers
66 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 ...
2
votes
1answer
65 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. ...
1
vote
2answers
124 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 ...
0
votes
1answer
34 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 ...
1
vote
1answer
67 views

Additive genetic variance with $n$ loci

The genetic variance of a quantitative trait (the quantitative trait in question is fitness) can be express as the sum of two components, the dominance and additive variance: $$\sigma_D^2 + ...
3
votes
1answer
131 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 ...
1
vote
2answers
283 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 ...
2
votes
1answer
100 views

Earliest ancestor of humans who could integrate into modern society

Assuming the current model of human evolution to be correct, approximately when did the earliest ancestor of humans live, who was intelligent enough, that if raised from a young enough age, could ...
3
votes
3answers
757 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
0answers
68 views

What is the biochemical pathway of fluoride?

Fluoride is a common active ingredient in tooth paste to prevent dental caries. It is also added or removed from the water supply in some communities for the same reason, but in children only. My ...
2
votes
1answer
69 views

Evolution from Mating types to different sexes

Imagine a lineage of multicellular organisms that had mating types and evolved their mating types into sexes. What are the possible mechanisms that might have brought this lineage to evolve sexes from ...
11
votes
1answer
2k views

How does translational coupling work in prokaryotes?

Today I heard about a phenomenon called "translational coupling", where the translation of one protein influences the translation of another protein. The messenger RNA levels don't seem influenced. ...
1
vote
2answers
179 views

Hardy-Weinberg Equilibrium: To compute probability of finding two siblings (random mating)

I've been working a little with M. G. Bulmer's Principles of Statistics (Dover, 1979) and cannot see how to properly compute half of one question. This should be a basic probability computation, but I ...
2
votes
1answer
598 views

What is Luc Montagnier's research on electromagnetic signals from DNA about?

After reading a Youtube comment, I started reading on Luc Montagnier's research on electromagnetic signals from DNA. I haven't been able to find a source that would clearly explain what it's about. I ...
1
vote
1answer
224 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 ...
6
votes
2answers
166 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 ...
6
votes
3answers
382 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 ...
6
votes
1answer
305 views

Why is membrane potential not zero at equilibrium?

For the squid giant axon, the membrane potential computed by the Goldman equation is -60mV. And the Nernst potentials are (the differences between the K+ and the Na+'s Nernst potential and the ...
1
vote
0answers
27 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) ...
1
vote
2answers
168 views

Do people often blow out the air from their lungs a lot when living in the cold condition to keep their lungs warm?

In a cold climate, do people often blow out the air from their lungs a lot when living in the cold condition to keep their lungs warm? I asked this question because it could connect to how people in ...
2
votes
1answer
54 views

What are the longterm effects of pancreatitis?

As the title asks, what are the longterm effects of pancreatitis? Having one event, is the person more susceptible to have a recurrence, or are they at higher risk of other conditions such as ...
1
vote
1answer
102 views

Which hormones/factors affect Calcium absorption in the small intestine and its regulation?

I think the question is very broad and cannot find precise mechanisms. I am not sure about the precise mechanisms of the regulation. I think they are at least Vitamin D, diffusion and specific ...
1
vote
1answer
70 views

Can we use Acetyl Phosphate instead of Acetyl CoA in TCA?

I am thinking Citric Acid cycle and activation of the end parts of Acetyl and alfa-ketoglutarate. Let's consider only now Acetyl to make things simpler. I have tried to explain the thing by symmetry ...
8
votes
2answers
573 views

Would exposure to a strong magnetic field have deleterious effect on the human?

This article states of a 25T magnet, ".. If are ever caught in one of these devices, let’s just say you probably won’t live to tell the tale." Is the above statement in order? What effect would ...
2
votes
1answer
71 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 ...
2
votes
3answers
74 views

Where can I find an at least Semi-Comprehensive list of what biochemical reactions Acetyl-CoA participates in?

Acetyl-CoA has a number of biochemical roles in the body and I'm curious as to whether anybody knows where I can find at least a semi-comprehensive list (i.e. comprising all the major roles in the ...
1
vote
0answers
38 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 ...
4
votes
2answers
524 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
164 views

Is AT or GC content important in electrophoresis?

Will it make a difference in running speed if we run samples of same no of bases but different AT - GC content ?
4
votes
3answers
349 views

Antigenic and non antigenic

Can any foreign molecule be non- antigenic ? Can any foreign peptide be non-antigenic ? What is the difference between an antigenic and a non-antigenic peptide ?
4
votes
2answers
97 views

Why do plasmids replicate on their own?

I know how plasmids can replicate independently of the main genome and know that they confer various properties to the bacteria and are useful in conjugation. My question is - what is the advantage ...
2
votes
1answer
179 views

Genetics problem-Height of a plant

An inbred strain of plants has a mean height of 24cm. A second strain of the same species also has a mean height of 24cm. When these plants are crossed the F1 are also 24cm in height.However, when the ...
2
votes
0answers
38 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
75 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
71 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 ...
1
vote
2answers
78 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?
3
votes
1answer
77 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 ...
1
vote
1answer
79 views

Is there any documented case in which floating substances led to the introduction of a new species?

Floating substances in the marine or freshwater environment often carry hitch hiking organisms. It is argued that many species may use this dispersal vector to reach new habitats, however to my ...
0
votes
1answer
177 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 / ...
2
votes
1answer
547 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 ...
0
votes
1answer
55 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 ...
2
votes
1answer
269 views

what is the effect of soda water on digestion?

what is the effect of soda water on the process of digestion? As it has been seen that after drinking soda the process is increased...I just want to know that what is the chemistry behind this?
0
votes
1answer
40 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 ...
3
votes
2answers
433 views

How was the Huntington's disease gene's location found?

I read in the book "Why we get sick." by Nesse and Williams that: Steady detective work and fabulous luck have enabled geneticists to pinpoint the Huntington's gene on the short arm of ...
2
votes
1answer
82 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 ...
1
vote
1answer
2k 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 ...

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