All Questions

3
votes
3answers
208 views

Where does crop biomass come from?

Each year, large volumes of crop are harvested from fields. Where does this biomass get replenished from?
2
votes
1answer
31 views

Relieving pain by massage

How come the pain in our body, primarily due to excessive physical exercises, vanishes after having a massage? What is the mechanism?
3
votes
1answer
45 views

What could live inside a pillow? [closed]

I have a phobia of bugs (or other small creatures) living inside my pillow and crawling into my ear in the night. It might seem silly, but bare with me. Recently I got wondering, what organisms ...
2
votes
1answer
43 views

Does eating bananas help digestion? [closed]

I don't know what I am asking is silly or not, but I have always heard that eating a banana after a meal helps in digestion. Some people says before food while others say after. Is it a fact or some ...
2
votes
1answer
2k views

Do T-cells express MHC molecules?

T-cells recognize the MHC molecules and body's own peptides. When it doesn't, it alarms the immune system. But do T-cells express MHC molecules ? If so, how are they using it? If not, what happens ...
2
votes
0answers
30 views

Imperfect dosage compensation

Dosage compensation is used to make up for different copy numbers of the major sex chromosomes in males and females (One X or Z chromosome in one and two in the other). Two main mechanisms of dosage ...
1
vote
2answers
33 views

Animal swimming styles

Can a frog swim on its back, or it can use only the classic frog style? Does any (not specifically marine) animal exist with many different swimming styles, just like humans?
2
votes
0answers
26 views

How to evolutionary explain menstrural cycles synchronization?

Sorry, I can not indicate the source, but I read that menstrual cycles of women who live in the same house over time sync. Is it true? How does it work?
1
vote
1answer
41 views

Definitions of robustness and canalization

The concepts of robustness and canalization are fashionable today in the biology literature. However, I am not sure of their definitions and I am not sure either that all authors actually use the same ...
1
vote
1answer
28 views

What is the common diet of food-related IBS patients? Besides most patients being lactose intolerant, what other intolerances do they face?

I am currently writing a paper on irritable bowel syndrome, and I was wondering what the common diet of a patient with food-related IBS consists of. I've already begun discussing the pathogenesis of ...
9
votes
1answer
110 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 (Big genome size)? energy for copying? raw material for copying? space in the cell? Maintenance cost (matter and ...
1
vote
0answers
19 views

Insects or Birds covering least distance but most wing moves

I was in search in of list or detail about Insects and Birds which move their wings most but cover least distance. I know that in insects house fly moves its wings about 200/sec and covers 5mph ...
34
votes
2answers
6k views

Can a woman give birth to twins with different fathers?

Is it possible for a woman to conceive from two different men and give birth to half-siblings?
4
votes
3answers
144 views

Results of a complete DNA sequencing - are they 100% reusable?

Is that correct that a complete DNA sequencing (the whole genome) need only to be done once (per person)? After that is done, it the complete genome can be stored and once the new genes (and their ...
5
votes
1answer
94 views

What are the psychedelic effects of (stellar) anise and how many people are affected?

Backstory: My girlfriend reacts heavily to chocolate and drinks containing stellar anise, in a way that seems comparable to psychedelic drugs. After consuming it, it takes approximately five minutes ...
6
votes
0answers
68 views

effect of pupil responses on the electroretinogram

The electroretinogram is generally considered to reflect the retinal processing of a light stimulus, typically a photoreceptor response followed by secondary neuronal activity. However, I am wondering ...
2
votes
1answer
70 views

A subtle test for color-blindness [closed]

Is there a test method of proving a person being color-blind, without letting the test subject know, that he/she is being tested? E.g. showing the person cards with colored dots like depicted here is ...
1
vote
1answer
30 views

Why is LH level much higher than FSH level at ovulation?

My teacher showed us an elaborate collection of graphs with one of them showing FSH and LH plasma levels during the menstrual cycle. LH level was almost 3 times higher than FSH level. Why? Does this ...
11
votes
4answers
75 views

Is there a period after you have had a cold when you cannot get a cold again?

I always assumed colds ran on a 'no tagbacks' principle: once it's out of your system, it takes a while before you can get a cold again. Is there any truth to this, or can rhinoviruses hit you at any ...
7
votes
4answers
329 views

What prevents predator overpopulation?

I've often heard that a population, human or otherwise, will continue to grow as long as there is food available (assuming nothing else is killing them off). It makes sense: if you have food you can ...
4
votes
1answer
26 views

Need for two oxygen sensors in E. coli

E. coli has two oxygen sensors: FNR (fumarate-nitrate reductase) and ArcBA (Anoxic Redox Control, two component control systems). FNR directly senses the oxygen, while the interaction of ArcB with ...
4
votes
1answer
30 views

Examples of genes involved in plastic responses

Adaptive plasticity involves sensing the environment and responding adaptively to it. Intuitively, I would think that this process may ask for a more or less complex genetic machinery of regulation of ...
5
votes
2answers
71 views

How do diving marine mammals avoid decompression sickness?

How do marine mammals, whose very survival depends on regular diving, manage to avoid decompression sickness or "the bends?" Do they, indeed, avoid it?
4
votes
2answers
233 views

Double mutant analysis with null mutants

My professor was talking about double mutant analysis with null mutants, and how double mutant analysis won't work with hypomorphs. I really don't understand the concept of double mutant analysis. ...
4
votes
1answer
34 views

Drake's Law. What is the genome-wide mutation rate and what are the estimates?

Drake's rule Drake's rule states that the genome-wide mutation rate is more or less constant across all species — from E.coli to the house sparrow. Data From what I think being Drake's original ...
13
votes
3answers
505 views

Why is there a difference in the rotation of the tail fin in fish compared to marine mammals?

I've been thinking about this one, but I can't seem to find what causes this difference. All fishes that I've seen have their tail fin positioned vertical: But all the marine mammals I know have ...
3
votes
2answers
64 views

Why does caffeine give you so much energy, while being so low on calories?

There's definitely something I'm missing here. Since calories is a unit of measurement for energy, and caffeine seemingly gives you a lot, how can the labels on caffeinated products have such a low ...
0
votes
2answers
43 views

Can you build muscles from watching point of view videos of people weightlifting?

According to this, "new research has found that viewing other people exercise actually increases your heart rate and other physiological measures, just as if you were working out yourself". This got ...
1
vote
1answer
47 views

What is the difference between embryology and developmental biology?

The question is quite explanatory in it self, I used to think that both are same but then find somewhere that embryology is a part of developmental biology, can somebody please elucidate?
2
votes
1answer
34 views

Do invasive species survive in the long run?

If an invasive species preys on native species, spreads widely and becomes dominant, should it not become extinct soon enough because of a lack of food?
1
vote
0answers
43 views

Is there biological evidence for self-awareness in animals?

I am conducting an investigation into the topic of the intelligence of animals, in particular farm animals. I would be interested to hear a scientific and biologic perspective as to what is perceived ...
2
votes
2answers
17 views

Food allergen-related skin reactions and intestinal inflammation?

Are there any connections between food allergen-related skin reactions causing intestinal (or more broadly, gastrointestinal) generalized inflammation? If such a link exists, is it related to any of ...
1
vote
1answer
90 views

What are the buoyancy control mechanisms of Chambered nautilus?

I'm currently working on an underwater robot and was hoping to use the principle used by the nautilus for buoyancy control. So how do the Chambered nautilus control its buoyancy?
1
vote
1answer
53 views

Has DNA communication/interaction at a distance been empirically demonstrated?

I recently had a discussion with a statistician in my school about memory. Among other things, he told me that it has been experimentally demonstrated that when one extracts DNA from any organism and ...
1
vote
0answers
20 views

Cells with no apoptosis mechanism and their 'byproducts'

If a culture or sample of cells is such they all have no apoptosis mechanisms yet they have not been at present determined to be cancerous ; given such a cell culture is there a way to determine by ...
3
votes
1answer
78 views

Why did humans lose their fur?

The little amount of body hair humans have don't seem to be of much use for keeping warm. Our Simian cousins on the other hand sport thick furs. At which point during the species evolution and why ...
5
votes
2answers
52 views

Is there are practical lower limit to gene length in E. coli?

Question is rather self-explanatory. Putting aside other post-transcriptional factors like rate of degradation of transcript, what is the smallest gene ever reported to have successfully been ...
3
votes
2answers
34 views

Heterochromatin production limitations

Currently playing with some ideas for a project and needed some guidance. I am wondering, both in Drosophila melanogaster and in general, is the amount of heterochromatin a cell/nucleus can produce ...
5
votes
1answer
72 views

Gender and age-specific mutation rate in plants

Background General concept According to Cochran and Harpending (2013), mothers transmits on average a number $x$ of new mutations to their offspring. This number $x$ is independent of the age of the ...
0
votes
1answer
31 views

What roles do cyclooxygenase, lipoxygenase, and epoxygenase have in signal transduction?

Besides oxidizing fatty acids to form prostglandins, leukotrienes, and epoxides, what other roles do cyclooxygenase, lipoxygenase, and epoxygenase have in signal transduction?
4
votes
1answer
2k views

What are differences between formation of embryonic disc in chick and mammal embryo?

Exam question which got lowest average points in my university: 1/5 average. No markscheme available so my attempt below. I assume that embryonic disk prefers to germ disk such that Formation prefers ...
1
vote
1answer
31 views

Local BLAST Copy Number per Hit

I generated a series of local BLAST databases using makeblastdb of metagenomic data and am searching for the presence of a particular gene. While I can do the normal BLAST analysis looking at ...
0
votes
2answers
40 views

Are all single-celled organisms Bacteria?

I read that "Bacteria are one-celled organisms that can multiply by division", are all one-celled organisms bacteria or are there any more narrow definitions?
1
vote
1answer
49 views

Fast standing and the heart's insufficient accommodation of the increased venous return

Assume you are 45 minutes on the supine position. Furthermore: you stand all of a sudden and fast and without sympaticus activity. The venous return (smooth musculature of vessels) accommodates ...
2
votes
1answer
40 views

PSI-BLAST website algorithm parameters

http://blast.ncbi.nlm.nih.gov/Blast.cgi In this website, when I want to apply the psi-blast algorithm on a sequence, under the section of algorithm parameters , what does PSI-BLAST threshold mean? ...
3
votes
2answers
46 views

Tracking of oxygen molecules in glucose oxidation

For this reaction, found in typical biochemistry textbook: $C_6H_{12}O_6 + 6O_2 \to 6CO_2 + 6H_2O$ I am interested in where do the oxygen atoms of $6O_2$ go. I think they go to $6H_2O$, but this is ...
3
votes
1answer
35 views

Why are the genomes of some trees so large?

For example, the current longest known genome belongs to a tree: http://motherboard.vice.com/read/the-largest-genome-ever-sequenced-belongs-to-a-tree I have heard that this could potentially be ...
2
votes
1answer
56 views

What is the mechanism behind ventilatory acclimatization?

In my respiratory physiology lectures, my professor explained that hypoxia-induced hyperventilation occurs in 2 stages when people try to acclimate at high altitudes. My question is about the ...
2
votes
1answer
31 views

What is the most recent well-attested common ancestor of chimpanzees and humans?

Humans and chimpanzees are related and thus have a most recent common ancestor. Of course pinning down this precise point is essentially impossible, so I'm interested in close ancestors of this most ...
4
votes
1answer
94 views

Do blind people learn Braille equally fast as the sighted? [closed]

The visually deprived brain undergoes extensive remodeling due to cross-modal plasticity. This leads to increased areas of the cortex being available for other purposes such as tactile processing. Now ...

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