4
votes
1answer
2k views

What part of the brain controls depth perception?

Specifically the part of the brain that does depth perception based on binocular vision. I have searched all over the web and have turned up nothing. Is it the same part of the brain that processes ...
3
votes
1answer
396 views

Is a “Fact” any theory for which there is overwhelming evidence in any field other than biology?

Evolution is often described as a fact, and a theory. Evolution is a heavily overloaded term, with one definition being the fact that, "changes in the frequency of alleles in populations of organisms ...
2
votes
2answers
939 views

Are human males and females more genetically different than members of other species?

I'm looking at this Ted talk about a Saudi Arabia woman who dared to drive a car in the last few years. This reminds me that until the last century or so, women (all over the world?) enjoyed less ...
3
votes
2answers
306 views

By what mechanism does coeliac disease cause excess fat in the feces?

Wikipedia states that “Severe coeliac disease leads to the characteristic symptoms of pale, loose and greasy stool (steatorrhoea)”. However thumbing through the causes and the pathophysiology it did ...
3
votes
1answer
223 views

Precursor miRNA and a mature miRNA

What is the main difference between a precursor miRNA and a mature miRNA? It is often the case that we have more than one precursor miRNA but only one mature miRNA. The miRNA-seq data contains only ...
6
votes
1answer
2k views

Why do neurons have a negative resting potential?

Neurons expend the majority of their energy powering ion pumps to maintain the chemical gradients that power their electrical activity. To have a negative resting potential, neurons leak potassium ...
1
vote
0answers
109 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?
1
vote
2answers
1k views

Why do antibiotics have a special importance when taking lactulose?

“Before taking lactulose, tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially antacids, antibiotics including neomycin (Mycifradin), and other ...
1
vote
1answer
564 views

Why do antacids have a special importance when taking lactulose?

“Before taking lactulose, tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially antacids, antibiotics including neomycin (Mycifradin), and other ...
3
votes
1answer
128 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.” ...
8
votes
2answers
389 views

How do ants sense imminent rainfall?

I have always been told to watch to see if ant-hole mounds are built up as a sign of imminent rainfall. My questions are, if what I have always been told is true, then by what mechanism do ants ...
4
votes
0answers
100 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 ...
0
votes
1answer
55 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.
3
votes
1answer
78 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
1answer
115 views

Electron transport in granal stacks

See paper for distribution of PS-I and PS-II within grana As explained in the above paper, the PS-I complex is primarily located within non-appressed thylakoid region and stroma lamella, while PS-II ...
5
votes
1answer
94 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 ...
2
votes
1answer
769 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, ...
2
votes
2answers
98 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 ...
2
votes
1answer
55 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?
2
votes
2answers
8k views

Can the excessive consumption of mineral water lead to kidney stones or other health issues?

I heard that drinking too much mineral (bottled) water could lead to problems such as kidney stones because of the high amount of minerals in it. Is it true? If so, what is considered to be excessive? ...
2
votes
2answers
161 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
198 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 ...
1
vote
2answers
69 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 ...
1
vote
1answer
1k 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
66 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?
6
votes
3answers
187 views

Why are males more likely than females to have autism spectrum disorder?

The male to female ratio in autism spectrum disorder is around 4:1. However it seems ASD is not a simple X-linked disorder. Then how is it possible males are more susceptible than females, if the ...
1
vote
1answer
405 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 ...
0
votes
2answers
119 views

Sewall Wright for dunces

[This is one more post in my growing "X for dummies/idiots/morons/etc." series.] I've been enjoying Provine's The origins of theoretical population genetics for the last couple of days, but I must ...
1
vote
3answers
316 views

What flying insect is this?

Found in Russia. Approx. 7 cm.
4
votes
3answers
1k views

Polymorphism in cnidarians?

To me, the phenomenon of polymorphism in cnidarians is particularly troubling. I gather that it essentially refers to existence of various different forms or kinds of individuals, i.e. zooids and ...
2
votes
2answers
508 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 ...
0
votes
1answer
2k views

Structure of adenoids

I am not sure this question belongs in biology, but I can't find a more suitable stack exchange site, feel free to delete it if this doesn't fit here. Also, this question is going to be slightly ...
5
votes
1answer
178 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
2k 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
103 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
1answer
2k views

What are the differences between G+ and G- bacteria?

The distinction between Gram-positive and Gram-negative bacteria is based upon the Gram staining method, that reflects the bacterial wall physical properties. However, this classification involves ...
0
votes
2answers
144 views

Blood circulation and blood pressure in different tissues [closed]

The volume of blood coursing the blood circulation is approximately five litres. A typical vein will stretch about eight times as much as corresponding artery. Because veins have high capacitance, ...
5
votes
3answers
392 views

How is antibody production stopped?

Once clonal selection is done, B cells would start dividing and producing antibodies. So, after an antigen is eliminated, what stops the division of B cells and antibody production?
4
votes
1answer
87 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 ...
2
votes
1answer
44 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?
0
votes
3answers
80 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 ...
1
vote
1answer
148 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. ...
2
votes
1answer
236 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 ...
2
votes
2answers
212 views

Change in conditions of an ecosystem lead to change in organisms

Let's think about the slash and burn method and its effects on the ecosystem. Cutting down trees that rise all the way up to the canopy would expose the plants at ground level to more light, so would ...
1
vote
1answer
116 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 ...
2
votes
1answer
79 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?
7
votes
1answer
146 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
1answer
45 views

How can I learn about how cloning works in nature (twins)?

I would like to learn about how the process of cloning works in nature - how are twins "created" after fertilization what genetic changes can occur in each of the twins. Where should I start? What ...
4
votes
1answer
130 views

Is it possible to condition the body to reduce bruising?

I do combat sports, and in these sports there are a lot of hits that can cause bruising. I've found that, over time, physical conditioning can reduce and/or eliminate the bruising to the point where ...
4
votes
1answer
294 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 ...

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