2
votes
1answer
75 views

Animal UV vision

It is reasonably well known that many species, such as bees and some types of birds as examples can see into the ultraviolet (UV). How is the structure of their eye different to humans to allow this? ...
2
votes
0answers
77 views

How is ammonia removed from the colon?

“Lactulose is also used to reduce the amount of ammonia in the blood of patients with liver disease. It works by drawing ammonia from the blood into the colon where it is removed from the body.” ...
1
vote
3answers
251 views
0
votes
2answers
133 views

What beetle is this?

I've found it in my kitchen. It seems to be that he flew through the window from the street. The country is Russia.
0
votes
1answer
51 views

Is every cell competent?

I would like to know if every cell is competent or if there are any cells that are not competent.
1
vote
0answers
78 views

What is neutral genetic differentiation?

What is neutral genetic differentiation? Presumably it's a measure of the distance between organisms in terms of their genetics, but what does 'neutral' refer to?
3
votes
1answer
6k views

What is the functional difference between hemoglobin and ferritin?

I read that both hemoglobin and ferritin are for storing iron in the body. So, what is the difference between them in terms of storing/binding iron?
2
votes
2answers
92 views

E. coli, risk of infection?

There has been a warning about E. coli contaminated water in South Florida. Now I'm wondering are there empirical data or historic cases which show a correlation between E.coli levels in tap water and ...
3
votes
3answers
555 views

Why do neurones use chemical signalling at synaptic junctions?

Problem. When a neurone fires, it sends an electrical signal that jumps down the axon via the nodes of Ranvier very rapidly. At a synaptic junction, chemical brownian diffusion signalling with ...
2
votes
0answers
77 views

Eye color genetics

I am trying to find a model to link the phenotype eye color to its genotypes. I know that there exists a simple model from Davenport, which explains {brown,blue} eyes. Further, there is an extended ...
2
votes
1answer
453 views

What is the relationship between UV wavelength and penetration depth into human skin?

Some background - Some recent research has strongly suggested that UVA penetration into the skin is far more dangerous than UVB, a very good example is this paper by Agar et al. (2004). My query is, ...
4
votes
3answers
104 views

Is there any source for raw data of SNP genotype frequency?

On sites like SNPedia, some pages contain the frequency of the SNP in question in different populations, based on published research. I'm trying to write a script that takes 23andme data and compares ...
5
votes
1answer
86 views

Photosynthesis regulation

I read about the regulation of Calvin cycle by thioredoxin which activates key enzymes essentially by converting disulphide linkages on inactive enzymes into sulfhydryls. Another regulatory mechanism ...
4
votes
1answer
65 views

How can I save bacillus strains on filter paper without an -80 degree freezer?

I want to save my bacillus strains but I don't have access to a -80 degree freezer. What are possible alternatives?
1
vote
2answers
117 views

Which texts are good for beginners to understand evolution on the genetic scope?

Are there good texts to study the evolution, how it works, and how mutations and changes lead to evolution of the organism ? And how does the information increase through the long time using ...
4
votes
1answer
163 views

How is consciousness linked to the brain?

Could the brain be working without consciousness? Does the brain interact with consciousness? Alternately, is it that consciousness can't really control the brain, and you only have the impression ...
2
votes
1answer
51 views

Deep diving in mammals

Mammals like seals often dive and can remain under water for more than 70 minutes. How do seals know when is it the time to come up?
1
vote
2answers
60 views

Are there beneficial genetic mutations identified by consumer DNA genotyping?

I'm looking at services like 23andme, and see that they identify a wide variety of genetic-based risks, like predisposition to diseases, hair loss, cancer, etc. Are there a more "positive" DNA ...
44
votes
2answers
1k views

Is there any evidence that sexual selection may lead to extinction of species?

Darwin suggested that sexual selection, especially by female choice, may counter natural selection. Theoretical models, such as a Fisherian runaway process, suggest that evolution of preference and ...
5
votes
1answer
230 views

Are there any side-effects from a mosquitoes extinction?

Suppose that we have the ability to make mosquitoes extinct, what would the side-effect of such extinction be other than the fact that there won't be any mosquitoes left? Is it worth it to make ...
1
vote
1answer
670 views

How do viroids propagate to other hosts?

As viroids are simply non-encapsidated non-coding RNA molecules, it is difficult to imagine a mechanism for their continual infection, other than horizontal transfer which doesn't seem to be the case. ...
1
vote
1answer
63 views

Breaking of fats

There is a question I encountered. Why is fat harder to digest ? A) It has ester bonds. B) It is not easily soluble in water. Which is the most appropriate answer?
1
vote
1answer
313 views

What is a good Microbiology atlas for Bacteriology as online version?

I am looking for a online atlas for Bacteriology, the cost does not matter. I have been searching SpringerLink, and Amazon but no good online version found. What is a good atlas for Bacteriology as a ...
7
votes
1answer
427 views

How is the exogenous DNA protected from degradation during bacterial transformation?

During transformation, a bacterium can take up DNA from its environment. A small fraction of bacterial species are known to be naturally competent, meaning that they can engage in this sort of ...
2
votes
1answer
149 views

How do you average Ki values?

It's embarrassing for me to ask this but well such is life. NIMH Psychoactive Drug Screening Program (PDSP) Ki Database is mentioned as the source of the average binding affinity (Ki) values given in ...
2
votes
2answers
385 views

Transcription factor binding site located in intron

I have noticed that some TF binding sites are located in the introns of the genes. I am puzzled about whether the TF only binds to DNA in the initiation stage of transcription and will detach during ...
3
votes
1answer
342 views

Are there records of monozygotic twins in which one experiences androgen insensitivity syndrome

I have given my high school biology students the thought experiment of "What would happen if a researcher induced twinning of a female zygote and then replaced one of the X Chromosomes with a copy of ...
1
vote
0answers
773 views

Low RNA yield, low 260/230 ratio [closed]

I extracted total RNA from animal tissue using the Qiagen RNeasy kit, however my RNA yield was extremely low and the 260/230 ratio was around 0.3. This is the protocol I followed: The animal ...
5
votes
2answers
262 views

How does fever physically work?

What is the physical mechanism that causes temperature to rise during a fever? I know that somehow the hypothalamus "orders" to increase the standard body temperature regulation, and this should ...
4
votes
1answer
82 views

Are there any bacteria, in our environment, able to break down nitrate under aerobic conditions?

Given a fix volume of water saturated with dissolved oxygen through aeration. Suppose that ammonium, Nitrosomonas, and Nitrobacter are always available in the water. We know that some of the ammonium ...
5
votes
1answer
136 views

Is there a DNA test to identify dog mixes?

We adopted a dog at the age of two. Our vet said it was a mix of an Australian Shepherd and Border Collie, which we've told everyone. Based on markings, I think it's likely. I am wondering, however, ...
3
votes
1answer
1k views

How does a virus take control over the host cell?

When the virus integrates its DNA with the hosts and enters the lytic pathway, do the viral proteins that produced destroy the cells DNA? Do they deactivate it? Also does the cell function in the same ...
1
vote
1answer
62 views

Do Acyl Carrier Proteins and Conenzyme A have similar reactivity?

In terms of the reactions they undergo are they roughly equivalent groups?
1
vote
0answers
86 views

Is there a biological process which causes organs to atrophy in response to enivronmental stressors? [closed]

I am aware of what happens when the body experiences starvation and breaksdown the muscles in the body for protein sources and the other processes that happen in such a scenario. However, i wondered ...
21
votes
2answers
9k views

If a human takes antibiotics are all bacteria in the body killed?

From my basic understanding, antibiotics kill living things, bacteria for example. Do the antibiotics consumed by a human-being distinguish between what they kill? Or do they just kill every bacteria ...
0
votes
3answers
76 views

What are the allowed evolution operators (on protein encoding sequences)?

What are the evolution operators, meaning allowed actions on the DNA sequence that encodes a protein. I assume all evolution of genes is a result of duplication errors. So an answer could look ...
2
votes
1answer
40 views

Are CoA and CoAS the same thing in a compound?

Is CoA-S-R the same as CoA-R, and is CH3C(=O)CoA the same as CH3C(=O)SCoA? Eg. Above is the compound on the right just coenzyme A or is it actually another compound and not just notation?
5
votes
1answer
56 views

What regulates these two methods of splicing?

Alternative splicing can shuffle the exon order and select from the exon sequence of a single gene site to provide a combinatorial selection of possible transcription products from the one gene. Can ...
1
vote
0answers
36 views

Randomized experimental design in genetic experimentation. [closed]

I am struggling to find out if randomization is used in traditional genetic breeding experimentation with model organisms, especially in lab contexts? And why this should be so? This is part of a ...
2
votes
1answer
69 views

Autophagy in eukaryotic cells

What is autophagy? How and under which circumstances is it used by the cell? I believe The reason for autophagy is some kind of recycling, am I right? But why does it occur in infections?
1
vote
1answer
126 views

Do nerve cells cause action potential in cardiac muscle?

I think the answer is no, but I am not 100% sure. If it was yes, then the dendrite of the nerve cell should each time receive a stimulus causing Na+ channels to open, when the contraction happen. ...
5
votes
2answers
574 views

Can proteins move outside cells?

I am trying to learn about basic cell biology, and have what is probably an extremely simple question. So this is how I understand it so far: Proteins are made from amino acids. This process is ...
2
votes
1answer
120 views

Can songbirds mimic car alarm sounds?

A silly question. A few days ago I observed a very vocal bird with impressive vocal variety. It was rapidly switching from one tune to the next. After sometime I realized that the bird might be ...
5
votes
1answer
591 views

Is human face more resistant to cold than other body parts?

Walking outside tonight in -15˚C I realized an interesting observation: While I felt cold on most part of my body, my face (although the only uncovered part) didn't really feel cold. It registered the ...
6
votes
1answer
156 views

Does muscle growth trigger angiogenesis?

So heavier people generally have more blood than lighter people (this is why heavier people generally need to take higher doses of medication for the same effect of medication). They also have more ...
3
votes
2answers
639 views

Just how light-sensitive is ethidium bromide?

One lab I was in was paranoid about keeping it in a foil-wrapped conical tube; my current lab leaves it out on the bench (and it works fine for staining gels). It's the same company/concentration in ...
4
votes
1answer
183 views

Plasma cells and memory cells

What decides whether an activated B cell will get converted to plasma cell or memory B cell? Is it necessary that out of a mitotic division one will convert to memory B cell and the other to plasma ...
2
votes
1answer
405 views

Comparing BLAST and the Smith-Waterman algorithm

I've been asked: how does BLAST improve dynamic programming accuracy? I do know that BLAST is based on heuristic approach that approximates the Smith-Waterman algorithm and that the Smith-Waterman is ...
6
votes
1answer
127 views

Same 185th million grandfather?

I was watching a lecture by Richard Dawkins earlier today and he mentioned that “Your 185th million grandfather was a fish.” I started wondering about the following question, Is it true that my 185th ...
1
vote
0answers
32 views

Avian Diseases : How to Disinfect [closed]

How can I sanitize a bird's carcass so that no diseases are present after disinfection? I was thinking $\gamma$-ray bombardment since ozonation would only surface disinfect.

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