0
votes
0answers
47 views

Enzymes and cofactors

About how much % of the human enzymes need cofactors? Like 20%, 30%, or 50% of a cell's enzymes? And how many enzymes work "alone"? This is a general question to figure things out. Do most enzymes ...
9
votes
2answers
2k views

How does life change when you dig deeper?

I've just realized that I have no idea what life / biotopes / soil looks like when you dig deeper than a few meters. I know that in the first meter of soil you can find all sorts of live animals ...
4
votes
1answer
65 views

Are aquatic filter feeders effective at cleaning water to a safe level?

I've been raising Daphnia magna cultures over the last few months as feedstock for freshwater aquarium fish. From my reading, Daphnia feeds on bacteria and single-celled algae, as well as other small ...
20
votes
1answer
281 views

Can someone identify this ant?

This is one of seven ant queens I just collected yesterday morning (2015-09-21 9AM) around home. I live in Hong Kong, at a hillside facing south. The weather was as follows (Hong Kong Observatory ...
1
vote
1answer
34 views

How good is the reproducibility of preclinical models?

Unofficially, biology researchers always complain how frequently fail to replicate results others have achieved. But of course, such failed experiments are underreported. Is there data, or at least ...
1
vote
1answer
123 views

What percentage of people today would likely be descendants a man born 4,000 years ago?

Assuming a particular man was born in southern Mesopotamia, around 4,000 years ago, and was significant involved in a major religion. To what degree (if any) of accuracy could his descendants be ...
3
votes
2answers
57 views

Is there a way to know how many sodium channels are active (conducting) at a given time in the brain?

I was doing some reading about anti-epileptic sodium channel blockers, then wondered how many sodium channels are actually conducting (actively passing ions) at any given time, that is, in an ...
1
vote
0answers
36 views

Plasmid with ITPG and pBR322 ori

I'm looking for suggestions as my internet searches aren't turning up much. I'm trying to find a plasmid that has the pBR322 origin, as it's low(ish) copy number and can tolerate large inserts. ...
0
votes
1answer
84 views

How do we perceive acceleration?

Today me and my friend were coming on motor bike and I was sitting opposite direction because I was holding something in my hand (and it was fun :P). When he started bike I felt very high ...
4
votes
0answers
34 views

Why do some Brown Pelicans have orange or reddish parts on their bills?

I am doing research on Brown Pelicans and have photos/descriptions of the breeding and nonbreeding appearances of adults, esp. the California and eastern subspecies here on our southern Pacific, Gulf ...
11
votes
1answer
2k views

How can frogs tolerate freezing while humans cannot?

A wood frog can tolerate the freezing of their blood and other tissues. wiki, news2, but human beings can not. Some people plan to freeze their bodies/brains after death, and some of them have done ...
1
vote
1answer
62 views

Folding of bulliform cells

How do bulliform cells cause a leaf to fold in half when the leaf looses water? Also, how would these bulliform cells be arranged to cause the cell to instead curl up?
1
vote
0answers
52 views

Monocot stele in roots

Why do monocots have eustele in the roots instead of protostele like dicots? I thought the roots don't need the strength of eustele because the roots are supported by the soil. So what is the ...
1
vote
0answers
20 views

How to troubleshoot islet isolation

I have been getting very low yield from islet isolations from rats. My procedure is as follows: Inject the pancreas with 5mL Liberase (1 wunch unit/ml) in HBSS + HEPES through the CBD (decent ...
0
votes
0answers
82 views

Is there a genetic reason explaining the difference of the height of male and female?

Male and female height difference seems to be around 1.08 if all cultures are counted from these stats: https://en.wikipedia.org/wiki/Human_height Can this ratio 27/25 be explained by genetics and ...
4
votes
2answers
263 views

Why are there so many different humans yet chimpanzees are just chimpanzees?

There are two species belonging to the Pan genus (Pan troglodytes and Pan paniscus). That's just two. I mean, humans have changed radically since we split from chimpanzees, we have Australopithecus ...
5
votes
1answer
85 views

What is this tiny thing on the branch

I noticed a tiny spot with weird shape on the shoot of a plant (Variegata), and there are many others on other branches. I wonder what is it, this is a cropped picture of it, Thank you!
3
votes
1answer
62 views

Virus-to-virus gene transfer via “sequences integrated into a common host organism”

From "Risks from GMOs due to Horizontal Gene Transfer", by Paul Keese: In addition to direct HGT between organisms as depicted in Figure 1, forms of indirect HGT have been observed, which involve ...
5
votes
2answers
483 views

Evolution of endosymbionts?

Mitochondria and plastids in eukaryotes evolved through a process of endosymbiosis. How does an event like a eukaryote engulfing a bacteria, become a part of the genome? Some of these primitive ...
1
vote
0answers
50 views

Calculating the recombination factor of four point genetic cross?

So, I'm trying to work out the recombination factor (RF) from this set of data: Which shows the 16 phenotypes of progeny of a cross of Saccharomyces cerevisiae yeast. I know how to go about a three ...
2
votes
3answers
865 views

Do we consume dna, proteins of other organisms?

When we eat raw meat, e.g. chicken or fish, we are actually consuming the DNA, proteins etc. which are present in their cells. Wouldn't this affect our cell functions as this DNA might enter our ...
7
votes
1answer
322 views

How does a neuron change as you learn?

I am currently taking a course called "Introduction to Machine Learning with ENCOG 3", and I have a question about how well the Artificial Intelligence (AI) algorithm for a "neural network" ...
3
votes
1answer
140 views

How do eukaryotes terminate transcription? (clarification on Campbell Biology)

I'm having trouble understanding how eukaryotes terminate transcription. Studying Campbell Biology (pg. 342, 10th ed.), I read: In eukaryotes, RNA polymerase II transcribes the polyadenylation ...
3
votes
2answers
195 views

Why do veins undergo vasoconstriction during physical activity?

How would this help increase blood circulation?
1
vote
1answer
29 views

In vitro virus assembly

Are researchers able to assemble viruses in vitro? For example, I imagine that a phage display library may be generated by throwing in a test tube the capsid proteins (or what have you) along with ...
5
votes
1answer
147 views

The replicator equation vs the Lotka-Volterra equation

Background The replicator equation with $n$ strategies is given by the differential equation: \begin{equation} \dot x_{i} = x_{i} \left( \sum_{j=1}^{n} a_{ij}x_{j} - \phi \right) \qquad i = 1, ...
1
vote
0answers
18 views

Using Q solution with ready made MasterMix

I am exploring the possibility of using Q solution (5x) to get rid of non specific bands in PCR. I mostly use a MasterMix and not separate aliquots of dNTPs, Taq, buffer etc. In principle, adding Q ...
0
votes
0answers
49 views

Why is dsDNA nuclease activity by CRISPR/Cas9 only shown indirectly?

In Jinek et al., the authors show nuclease activity of their CRISPR/Cas9 system using the so-called Surveyor assay method. This assay recognizes small mismatches in dsDNA which are introduced by error ...
0
votes
0answers
15 views

Available soil water to plants

Textbooks say that when the water content of soil is greater than its field capacity, the water is not available to plants. Why? I know some plants can utilize water even from saturated soil, but for ...
2
votes
2answers
974 views

What are the differences between how glucagon and cortisol work to increase blood sugar?

As I understand, both cortisol and glucagon cause an increase in blood sugar concentrations. However I don't understand how they work differently or why they work separately. I would be very grateful ...
2
votes
2answers
63 views

Role of drift in evolution of sexually dimorphic traits

Is there a model for predicting how drift can affect the evolution of a sexually dimorphic (SD) trait? I've been trying wrap my mind around this paradoxical question; sexually dimorphic traits evolve ...
2
votes
1answer
83 views

How does Cas9 interact with CRISPR?

I read that Cas9 protein along with guided RNA binds at a specific DNA fragment of foreign organism integrated in a host organism DNA. To make the host immune to virus infection Cas9 along with gRNA ...
6
votes
1answer
294 views

How can I preserve hair or saliva for future genome sequencing?

Suppose I want to preserve myself so that I can be reproduced as best as possible, in future or be simulated in future. At the moment full human genome sequencing is a bit expensive. One could get ...
1
vote
1answer
70 views

How to interpret the simple sequence repeat (SSR) on the coding sequence, but not the related protein sequence?

I have predicted some SSR repeat on the gene of interest using SSRLocator program, which the result creates a question for me. Please consider the below sequence, which is part of gene sequence of ...
2
votes
1answer
63 views

Do oral vaccines exist?

Do edible vaccines exist, and if yes, what is their mode of action? Are there any edible vaccines commercially available now?
4
votes
1answer
114 views

Best method for measuring very young plant growth?

Is there a preferable method for measuring plant growth for a plant before the "sprout" stage? Preferably at the microgreen stage? I assume it would not involve some type of leaf based measurument, ...
2
votes
3answers
563 views

What is the biological significance of finding palindromes in DNA sequence?

I found a function called palindromes in Matlab that finds palindromes from DNA sequence. Now what is the biological intention behind incorporating this function? What the biological significance of ...
0
votes
0answers
61 views

The definition of leaf area index

In many textbooks, leaf area index (LAI) is defined as the total leaf area per unit ground area. I want to know LAI is defined only by leaves that are directly above the ground (e.g., perpendicular ...
5
votes
1answer
262 views

Why is it often the case that an enzyme is favorable only towards one direction of a reaction and not both directions?

In class when we're studying enzymes like amylase or protease it only works well when you're using it to break down compounds like polysaccharides. I'm just curious but why is it not possible for ...
1
vote
1answer
85 views

What is a detailed chemical explanation for describing how an enzyme may lower the activation energy of a reaction?

If you can provide some sound reasoning that touches on tertiary structures of proteins and does not use a lot of advanced chemistry jargon that might be really helpful, especially for an intro ...
3
votes
1answer
54 views

blastn: What substitution matrix is used?

I'm currently working aligning sequences, and I need to compute similarity between pairs of DNA 'words' of a particular length. For amino acids I am able to use the substitution matrices in Biopython ...
0
votes
1answer
40 views

velvet assembler contig lengths are wrong [closed]

Has anyone else found that the contig length listed on the sequence defline, and in other files, is 32 nt shorter than the actual sequence? Any idea why this might be and what to do about it?
0
votes
1answer
32 views

IBD-value and IBD-fraction

I have some questions about the IBD-value and IBD-fraction for two of the condensed identity states, $S_1$ and $S_7$. My questions: 1) Is the IBD-value for the individuals i and j two (2) in $S_1$ ...
0
votes
2answers
30 views

How can a sequence be downloaded from UCSC genome browser

If I have genome coordinates is there a simple way to download the entire intervening sequence from the UCSC genome browser? I found some fancy way of using ftp but I can't figure it out.
1
vote
1answer
70 views

Why insects are attracted towards light? [duplicate]

Many insects like bees, dragonflies, wasps and other small insects are attracted towards light. Sometimes they are in groups, sometimes they are in solitude. When the light source source is switched ...
1
vote
0answers
48 views

How does intron retention make the alternative transcript non-coding?

I faced with a non-coding transcript that specified as one the isoform of BIN1. It sounds that this isoform generated as a result of alternative splicing with a intron retained; am I right? However, ...
0
votes
1answer
49 views

Artificial Adrenalin

I was watching Sherlock Holmes - A Game of Shadows yesterday. I saw that he had developed a serum that causes a person to react like he has been injected with adrenalin. Watsons's dog fainted, I ...
1
vote
1answer
43 views

How do I offer a generous gift to sweet-seeking wasps, bees, hornets, bumble-bees?

I was having ice coffee and melon ice and after visiting the lavatory I saw that a wasp was having a good time with my already finished ice coffee. Trying to begin the melon ice the wasp kindly ...
0
votes
0answers
37 views

Why do I often see male robins with female robins?

Even when it is not breeding season for robins I still often see male robins with female robins. But why? I know that the male robin often chirps to find female robins within his territory. I also ...
2
votes
1answer
73 views

Fibronectin glass surface adsorption

Short summary I'm having a glass surfaces and I want to adsorb proteins onto them. I have no problem, when I first adsorb fibronectin (human) onto some areas and afterwards any other protein. The ...

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