3
votes
3answers
312 views

Where does crop biomass come from?

Each year, large volumes of crop are harvested from fields. Where does this biomass get replenished from?
4
votes
1answer
57 views

How to evolutionary explain menstrural cycles synchronization? [closed]

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
172 views

Why is the threshold between human embryo and human fetus defined as 8 weeks after fertilization?

Why is the threshold between human embryo and human fetus defined as 8 weeks after fertilization? What's happening on the 8th week? Note: definition of embryo based on Wikipedia's current ...
9
votes
2answers
342 views

How do insects survive the winter?

I had an interesting discussion today in which the question arose how insects survive in the winter. Since they need a high enough external temperature to be active, this seems a bit difficult in the ...
1
vote
0answers
39 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 ...
3
votes
2answers
4k views

Is there a difference between polarity and hydrophobicity?

From literature the two terms seem to be interchangeable when discussing protein domains and motifs. But biochemically, what are the specific differences between these two terms? For example what is ...
2
votes
0answers
62 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 ...
2
votes
1answer
50 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 ...
4
votes
1answer
42 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 ...
1
vote
1answer
169 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 ...
5
votes
1answer
96 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 ...
1
vote
2answers
69 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 ...
2
votes
1answer
335 views

(Updated question) Problem with Fold-change mean compared to absolute data (in qPCR)

For the problem below I am aware of the statistics involved but just can't get my finger around the following: In biology we use qPCR to measure gene expression or basically number of mRNA copies. It ...
2
votes
1answer
164 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
2answers
163 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
1answer
46 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
57 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?
3
votes
1answer
431 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 ...
11
votes
4answers
104 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 ...
1
vote
0answers
47 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 ...
45
votes
2answers
8k 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?
9
votes
2answers
326 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
1answer
212 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 ...
2
votes
1answer
98 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 ...
7
votes
2answers
1k views

How do marine mammals control buoyancy?

Presumably, as a whale or seal dives, its lungs get compressed by the increasing water pressure, and it gets less buoyant. Under this model, for a given amount of air taken in at the surface, the ...
2
votes
1answer
139 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
24 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 ...
5
votes
2answers
150 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
105 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?
10
votes
2answers
2k 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 ...
3
votes
1answer
68 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 ...
3
votes
2answers
138 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 ...
2
votes
2answers
165 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 ...
3
votes
1answer
95 views

What information can Uniprot give me about phosphorylated forms of proteins?

I have a list of proteins formatted like this: ...
6
votes
1answer
46 views

Would constant light or fading light be registered as more wakefulness promoting by the Supra Chiasmatic Nucleus?

During the fall and winter season, a number of people are experiencing Seasonal Affective Disorder. One of the way it has traditionally been treated is with a dedicated lightbox - a very high ...
3
votes
1answer
71 views

human immune system

The common cold and [some?] types of influenza are self-limiting. Some microorganisms cause self-limiting diarrhea. Is tuberculosis [potentially] self-limiting or not? To put it another way, suppose ...
7
votes
2answers
140 views

Evidence & discussions of hard polytomy

Phylogenetic trees with >2 branches on a node are polytomic, and polytomy can appear on trees for two reasons. Firstly a lack of information in the data prevents proper resolution within a clade, ...
6
votes
1answer
72 views

Nucleosome wrapping direction

Does anyone know which direction the nucleosomes are wrapped? I wonder: Relative to the B-DNA double helix twist direction (right-hand) Relative to the neighbor nucleosomes. Do they alternate to ...
1
vote
1answer
503 views

Hardy Weinberg problem help!

The three common genotypes at the hemoglobin locus have very different phenotypes: SS individuals suffer from severe anemia, AS individuals have a relatively mild form of anemia but are resistant to ...
3
votes
1answer
28 views

Ultra Pasteurization and Pasteurization

What is the effect of pasteurization and ultra-pasteurization on proteins, enzymes, and nutrients found in milk and other dairy products?
2
votes
1answer
34 views

Does the tannin level in plants go down or up after they die? Or does the tannin level stay the same regardless?

Does the tannin level in plants go down or up after they die? Or does the tannin level stay the same regardless? As they decay, do they release more tannins or does the production stop?
6
votes
1answer
134 views

Do blind people learn Braille equally fast as the sighted?

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 ...
1
vote
0answers
41 views

Dawn simulation - does color change affect waking up?

just curious. Are there any works or research results related to the influence of light color used for dawn simulation? I mean those wake-up lights which try to simulate dawn to make waking up better ...
-1
votes
1answer
61 views

Why the name coined for MARKUP LANGUAGE for SBML? [closed]

I'm get the confusion about SYSTEM BIOLOGY filed. SBML is refer to as SYSTEM BIOLOGY MARKUP LANGUAGE why we should called as ...
5
votes
2answers
491 views

Synthesis of immunoglobulin Fab fragments: Where can I learn about Fab?

I wanted to know the chemical reaction involved in Fab synthesis. I looked everywhere for it. No luck. I know I will find it here. All I know for now is: Fab is a monovalent fragment that is ...
4
votes
1answer
84 views

Phospholipid movement in cell membranes

What causes phospholipids to flow so quickly in cell membranes? In Biology by Cambell et al. they state that a phospholipids can travel up to 2 micrometers per second. Is that a random movement or has ...
7
votes
1answer
111 views

How often does bacterial transformation happen?

I have been reading: M. Dröge, A. Pühler, W. Selbitschka, "Horizontal gene transfer among bacteria in terrestrial and aquatic habitats as assessed by microcosm and field studies", Biol. Fertil. ...
7
votes
1answer
212 views

How many eukaryotes are there on Earth?

I have been reading: William B. Whitman, David C. Coleman, and William J. Wiebe, "Prokaryotes: The unseen majority", Proc. Natl. Acad. Sci. USA 95, pp. 6578–6583, June 1998. [Full Text] [PDF] ...
12
votes
2answers
1k views

Why does sex last so long?

I wonder why (especially human) sex lasts longer than just a few seconds? My thought is that the shorter it takes a man to ejaculate, the lesser is the risk that he gets interrupted by a rival or a ...
1
vote
0answers
96 views

Effect of flask position in shaking incubator affects growth kinetics

During some cultivation experiments for my bachelor thesis I noticed that in liquid culture my bacteria (E. coli) grew differently, according to the position in the shaking incubator. Because the ...

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