All Questions

2
votes
1answer
47 views

Quorum Sensing in Vibrio cholerae

This is a figure summarising the quorum sensing mechanism in Vibrio cholerae. In this video by Bonnie Bassler, she explains how quorum sensing can be targeted to control infections. At 15:09 she ...
2
votes
1answer
635 views

Is urine dirty as soon as it leaves the human body?

Human urine is sterile as long as it is in the human body. But is it dirty after leaving the human body? Could you get sick from it, if you drink it or don't wash your hands, for example?
6
votes
1answer
60 views

Absorption rate of Infrequently eating animals?

Clearly, creatures such as us humans, after vastly increasing the entropy of our food, expel most of the mass that we consume. Some creatures, however, do NOT get the opportunity to eat nearly as ...
17
votes
4answers
6k views

Can humans eat grass?

Can a human eat grass and digest it? Could it be possible to use it as food just like other plants such as wheat or beans?
0
votes
1answer
70 views

Systems Biology of triacylglycerol (TAG) synthesis in Jatropha

I need the genetic regulatory network of TAG synthesis (Kennedy pathway) of Jatropha plant?? Or is there any way to convert metabolic pathway into genetic regulatory network?
0
votes
0answers
42 views

Why do gay people exist? [duplicate]

I mean no disrespect to gay people - this question isn't intended to be judgemental or homophobic at all. I also know nothing about biology so please excuse my ignorance if this question ends up ...
0
votes
0answers
16 views

Southern/Western blot analysis and pedigree diagram? Help needed. [duplicate]

Hello everyone. I urgently need help with this question please. I have filled in the blanks using the results in the figure provided in the sheet. However, for number (b) is a little hard to ...
1
vote
1answer
110 views

Raising two legs together while lying on bed

Let's do some exercise(duh!) Ok so lie on the bed. Lift your left leg. Put it down. Lift your right leg.Put it down. Easy? Now lift your left leg and without putting it down, lift your right leg. ...
3
votes
2answers
89 views

Are viruses self-propelled?

So obviously, viruses are nonliving. But when my teacher was teaching viruses in the video (we're doing "flip" learning this semester), the way he described it, it seemed like the viruses responded to ...
0
votes
1answer
78 views

what these suffixes mean,-coel,-blast,-cyst? [closed]

in the connective tissue (Bones) we have 3 types osteoblast, osteocoel,osteocyst what are they and why they differ.
3
votes
2answers
98 views

What is the evolutionary purpose of the topology of the human ear?

What is the evolutionary purpose of the topology of human ears? I understand why the ears may have a funnel-like shape but if the various "hills and valleys" do not amplify incoming sound, what ...
1
vote
1answer
46 views

Do's and Don't's of Undergraduate Research? [closed]

I was fortunate enough to get a position as a researcher for the Mayo Clinic's SURF Program this year. My PI's lab focus is on the the immune system's role in CNS axonal and neuronal injury, ...
4
votes
2answers
895 views

No bands show up in gel electrophoresis, not even marker

I haven't seen any gel lanes in neither my PCR samples nor the marker itself when photographing them. This is not my first time performing 1.2% agarose gel electrophoresis. I see gel lanes when I ...
4
votes
2answers
138 views

Evolution in fruits

So, I saw a video on YouTube that says the banana we eat today is not what a banana looked like years ago. Since the banana has been genetically modified over the years, does that qualify as ...
2
votes
1answer
364 views

Why do cells vary in shape and function when they have the same genome and the same organelles?

Why do cells vary in shape and function when they have the same genome and the same organelles. For example: why do all cells have nuclei but red blood cell's don't; why can't the cells of a eye ...
11
votes
1answer
98 views

Beginning of the urogenital system

Are any invertebrate nephridia (proto/meta) homologous with vertebrate kidneys in the sense that embryologically they also begin together with the genital system? When did the embryologic association ...
0
votes
1answer
19 views

S. pyogenes' skin infection diagnostics

S. pyogenes is "flesh-eating" bacteria. It results from life-theatening myonecrosis caused by this organism. S. pyogenes avoids phagocytosis (mediated primarily by capsule, M and M-like proteins, C5a ...
3
votes
3answers
94 views

Why do 6-8% of diphtheria patients do not develop natural immunity after being affected?

I am thinking of why some patients do not have natural immunity after exposure to the A-B toxin of diphthria. I think the A-B exotoxin is the key factor causing this disease and should trigger memory ...
7
votes
4answers
557 views

Looking for a DNA sequence

I am not a biologist. Please pardon me, if my question does not make sense. I am trying to obtain a DNA sequence for pattern analysis in Matlab. I used to generate random sequence ...
3
votes
1answer
206 views

Parasitism and mimicry

I was reading this article which states this: Classical Batesian mimicry, in which an undefended mimic evolves to look like a toxic model, is a parasitic relationship in which the mimic gains ...
1
vote
1answer
41 views

Gene Complementation Question

Hi everyone! Here is a diagram of a genetics complementation problem. My main concern is regarding number 3d. I'm assuming that in this case, it would be complementary interaction and thus ...
2
votes
2answers
68 views

How does the telomere repeat sequence vary in Eukaryotes?

Question: How does the telomeric repeating sequence vary in non-vertebrate Eukaryotes? If you know the repeating sequence of a given species I would appreciate hearing it. Background: Telomerase is ...
3
votes
2answers
138 views

Electronic cigarettes (e-cigs), any health risks?

Background: An electronic cigarette (e-cig or e-cigarette) is a battery-powered device which simulates tobacco smoking patented in 1963 by Herbert A. Gilbert. It generally uses a heating element ...
3
votes
1answer
42 views

How do mosquitoes maintain telomere length?

While the vast majority of eukaryotic organisms maintain their chromosome ends (telomeres) via telomerase, an enzyme system that generates short, tandem repeats on the ends of chromosomes, other ...
7
votes
4answers
326 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 ...
2
votes
1answer
122 views

How do TLR1/TLR2 activate the MyD88 dependent pathway

Recently, I've been reading about the MyD88 dependent signalling pathway, with particular reference to its activation in Macrophages and other cells of the immune system on recognition of a pathogen. ...
1
vote
1answer
28 views

How host defends against S. pneumoniae capsule?

The host response involves at least phagocytosis and probably localised acute inflammatory response at least after the colonisation. I am thinking how the host can defend against pneumolysin which ...
6
votes
4answers
297 views

How many transcription factors are there?

In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow (or transcription) of genetic information from DNA to ...
2
votes
1answer
79 views

Plasmid maintenance

I have obtained some plasmids used as integration vectors, this question may apply to all plasmids. I would like to have a somewhat continuos source for these plasmids, let's say that the origin of ...
2
votes
1answer
269 views

How to check if a fastq file has single or paired end reads

I am trying to check if a fastq file has single or paired end reads. How can I achieve this with an error-proof method? I checked wikipedia and MAQ but I want to know if is there a reliable document ...
7
votes
1answer
61 views

Are recessive, deleterious alleles less common on the X chromosome than the autosomes in humans?

As there is a potential for them to be more readily purged in hemizygous males (and in cell lineages in females with the deleterious-allele-bearing chromosome activated), I would expect the frequency ...
4
votes
2answers
92 views

Is there a standard reference for the importance of tumor heterogeneity?

In a recent post, Philip Gerlee highlighted the two biggest contributions of mathematical oncology to cancer research: (1) increasing focus on the progress of cancer as an evolutionary process, and ...
4
votes
1answer
69 views

What is the relation between plasmid concentration and mRNA levels?

Suppose a simple synthetic construct, consisting of a constitutive promoter and a single gene: One of the simplest ways to model GFP transcription is to use an ODE: $\frac{d [GFP_{mRNA}]}{dt} = a - ...
1
vote
0answers
102 views

MTT assay normalization

Since the precise amount of cells in each well of an MTT assay varies, how can I normalize the results by cell number/concentration? How can I take into account the number of cells that have already ...
8
votes
2answers
430 views

Gloves for Cell Culture?

I always wear gloves when I'm doing cell culture. Moreover, I always spray my gloves with ethanol to disinfect, so that I don't contaminate everything. However, I recently heard the argument that ...
1
vote
1answer
23 views

Distribution of genotypes after adverse selection

I am doing some research into Mendelian genetics and came across this phrase called adverse selection. I found a few questions but I am unsure of the calculations. ...
1
vote
1answer
67 views

Genotypic distribution of a population with two characteristics and linkage

I am currently doing some research into distributions and probabilities with Mendellian genetics. I came across this problem that I cannot seem to wrap my head around. Given that the population has ...
0
votes
1answer
54 views

What does this sentence about toxemia and Clostridium tetani mean?

I know that Cl tetani is not invasive and strictly localised. I think toxemia means spread in the blood. I am thinking this sentence The volume of infected tissue is small, and the disease is ...
1
vote
1answer
151 views

What are the pros and cons of eating earth (soil)?

I wonder if there are any benefits to eat earth. What I mean by earth is the topsoil that is sometimes on vegetable (I eat organic vegetables and some of them like spinach are full of topsoil). I ...
1
vote
3answers
57 views

Using PSI-BLAST

I understand that the first BLAST yields almost the same results as blastp. The second time the iterated blast generates different results as it uses different matrix based on our first result. But I ...
4
votes
1answer
149 views

Why is Homo sapiens not categorized as an invasive species?

According to Invasive Species Advisory Committee (ISAC), the definition of the invasive species is “a species that is non-native to the ecosystem under consideration and whose introduction causes or ...
2
votes
1answer
50 views

PCR enzyme units or concentration?

When performing PCRs, usually in every protocol enzyme amount is specified as 1.25 U as optimal per 50 uL reaction. Then, when running 25 uL PCR reaction should i use 1/2 he amount the enzyme or ...
2
votes
1answer
47 views

Pippin prep kits - expiration date

Do you use Pippin prep? We would like to buy it, but we need more info. What is the expiration date of kits for Pippin prep? Thanks!
3
votes
2answers
70 views

What are the physiological roles of Hydrogen sulfide?

I am thinking why hydrogen sulfide has its effects in the body. For instance, it is one Salmonella's virulence factor. I am not sure if such a balance equations holds H2O + H2S ←→ ... Actually, I ...
2
votes
1answer
82 views

Do bacteria with capsular antigen always have a capsule?

Assume some bacteria have capsular antigen. Do these bacteria always have a capsule? I think not, I think the antigen only makes it possible.
0
votes
1answer
50 views

How can eating bacon not make me fat? [closed]

This page says it won't. This page says it's the carb again http://www.mindbodygreen.com/0-10454/in-defense-of-bacon-why-eating-fat-can-help-you-get-thin.html I don't see how eating fat will not ...
1
vote
1answer
65 views

Why will world population keep growing if all women have only 2.1 children

Why is it that, even if we were going to immediately agree that every women will not have more than 2.1 children on average, the world population would continue to grow for another 60 years? I've ...
1
vote
1answer
61 views

Hidden Markov Model

I read about the hidden markov model in bioinformatics. I amn't able to understand what it is. Can anyone explain me in brief and in very very simple words what it is ? I have NO background in ...
1
vote
0answers
34 views

Nearly Exhaustive List for Cholesterol Pathways

I have run across an interesting case that is similar to only two others I've encountered. What makes it interesting is the combination of undetectable (under normal testing conditions, can elaborate ...
1
vote
1answer
37 views

What are the purposes of granulocytes in acute inflammation?

I heard the phrase Neutrophilic leucocytes are kings in the acute inflammation. Neutrophils are granulocytes, while leucocytes are not granulocytes. I think this statement refers to the fact ...

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