2
votes
1answer
1k 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
2k views

The real definition of carbohydrates

Carbohydrates are often defined as compounds with only C, H, and O and the H and usually the O atoms are in a 2:1 ratio. Exceptions like deoxyribose exist, but why is it recognized as a carbohydrate? ...
0
votes
1answer
127 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.
0
votes
1answer
51 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
94 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 ...
5
votes
1answer
98 views

Could murder be modeled as an infectious disease?

Background "When swine flu hit the population it spiked in certain areas and tapered off in neighboring regions, it hits hardest where people have least protection and this pattern is more ...
2
votes
3answers
85 views

Quantitative Differences : DNA and Gene

After HGP, we are not having many databases which consist of several notepad files of ATCG.... Can we distinguish quantitatively a given A,T,C and G stretch as DNA or Gene?
7
votes
4answers
576 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 ...
0
votes
1answer
21 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 ...
4
votes
1answer
199 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 ...
3
votes
2answers
157 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 ...
1
vote
1answer
53 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 ...
4
votes
4answers
291 views

Biodiversity is restricted by genome combinatorics?

Me and some friends are interested in opinions for the following: Conjecture The maximum number of species must be limited by the maximum combinatorial/permutational space that can be occupied ...
3
votes
1answer
50 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 ...
4
votes
2answers
144 views

Asexual reproduction and Telomeres

Many eukaryotic organisms like yeasts, hydras , planarias, plants etc reproduce asexually. Replication of End of linear DNA pose a limit to the number of cell divisions. My question : Do asexually ...
2
votes
1answer
173 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
69 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 ...
2
votes
1answer
84 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 ...
1
vote
2answers
98 views

what does sequences overlap indicate

what does it mean if different protein sequences overlap upon multiple alignment, are they the same, do they have a common ancestor, are they recombinants of each other and how does one go on to ...
4
votes
1answer
116 views

Assumptions of Hamilton's rule

Which elements of the following list are assumptions of the Hamilton's rule? Population structure (non-panmictic population) Additivity = Fitness of the heterozygote equals the mean of the ...
2
votes
1answer
123 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.
1
vote
3answers
69 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 ...
1
vote
1answer
263 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 ...
4
votes
1answer
81 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 - ...
8
votes
2answers
546 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 ...
2
votes
0answers
153 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 ...
1
vote
1answer
27 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. ...
0
votes
1answer
80 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 ...
2
votes
1answer
76 views

Hibernation in ectotherm and endotherm

Both snake and weasel hibernate. Which of the following is correct? A. They will die when temperature decreases below the critical temperature. B. Weasel will die when temperature ...
2
votes
1answer
56 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!
0
votes
1answer
59 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
135 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 ...
0
votes
1answer
69 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 ...
9
votes
3answers
24k views

Healing process in mouth wounds

When we have an external wound the wound generally tents to clot and there is a layer of solid scab formed. Now,Yesterday while brushing my teeth i somehow hurt my gums and it got all bloody but ...
1
vote
1answer
171 views

What are some of the known fungi with heat resistant spores

Are there any fungi whose spores can survive 100+ degrees for 15 minutes and grow in a sugar-deprived medium?
1
vote
0answers
43 views

Nearly Exhaustive List for Cholesterol Pathways [closed]

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 ...
6
votes
1answer
74 views

Gap junction turnover

Gap junction proteins, connexins, are known to form intercellular hemichannels, between two adjacent cells. These junctions are maintained cell adhesion proteins (cadherins), yet the turnover of ...
5
votes
1answer
869 views

How to avoid air bubbles while pipetting?

I get air bubbles while pipetting small volumes. How can I avoid them ?
1
vote
1answer
90 views

Giardia lamblia cases of infections

I am wondering if anyone has seen a data of Giardiasis (Giardia Lamblia) cases in different countries on the world? I have found for different diseases and also for 'diarrhoea diseases' in general, ...
14
votes
1answer
4k views

Why do we grow so much hair on our heads compared to our bodies?

I've been wondering about head hair, facial hair in particular. Human males can grow very extensive beards should they choose to not shave - however you do not really see this in our chimpanzee ...
2
votes
2answers
247 views

Can Listeria monocytogenes endotoxin act as an A-B toxin?

I think no, but I am not sure since Listeria is Gram-positive and probably has lipopolysaccharide (exception among Gram positive bacteria). Can Listeria monocytogenes' endotoxin act like exotoxin ...
2
votes
2answers
82 views

What's the point of glycolysis in fermentation?

In order to get glycolysis started, you need 2 ATP. In the process, you can generate 4 ATP. That results in a net gain of 2 ATP. Hooray! But wait. If you don't undergo glycolysis, then you've got an ...
2
votes
2answers
380 views

Promoter in the lac operon

Here is the question: Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If she moves the promoter for the lac operon to ...
2
votes
1answer
98 views

eye myopia power changes with brightness

Is there a condition where myopic power changes with ambient brightness. When I drive in the morning in bright sunlight my power is -4.0; however when I wear the same -4.0 glass in the evening (dusk ...
6
votes
1answer
272 views

Primary cilia: what cell types have non-motile cilia that migrate?

My understanding is that there are two broad categories of cilia: motile and non-motile (also called primary. Examples of the former include sperm flagella and the cilia of epithelial cells that ...
9
votes
2answers
381 views

How are viruses weakened to be suitable for vaccination?

I understand there are two kinds of active vaccination Injecting complete viruses that are weakened to not cause the disease being vaccinated against Injecting only antigen particles of viruses that ...
1
vote
1answer
80 views

Diffusion of FAD+

Why is NAD+ free to diffuse within the mitochondrion whereas FAD+ is not ? What biochemical properties cause this difference ?
1
vote
1answer
338 views

All flowering plants gives fruits. Why does jasmine flower plant not yield fruits?

My question is actually my long term doubt. I have seen most of the flowers turning into fruits. But why not this jasmine flower?
0
votes
1answer
492 views

What is the significance of and biological mechanisms demonstrated in lac operon?

I would appreciate it someone could explain clearly how the genes in the lac operon of E coli are activated to allow the bacteria to metabolize lactose? The part that I really don't understand is ...
1
vote
1answer
77 views

parallels or replicates?

I am writing an article where I describe real-time PCR experiments. My collaborator, after reviewing the article, consistently replaced the word "parallels" with "replicates". Are they not synonymous? ...

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