All Questions

6
votes
1answer
1k views

Why does the T7 RNA Polymerase require a reducing environment ie. DTT

Every bloody protocol suggests adding in DTT when doing in vitro RNA transcription. Why? The rationale seems to be that the cytoplasm traditionally has a reducing environment but as the only protein ...
12
votes
3answers
463 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 ...
5
votes
2answers
139 views

Difference between biological control and introducing species for conservation?

I have a biology assignment and we have to explain various methods and strategies for conservation, two of which are: Biological control Introduced Species What is the difference between ...
5
votes
2answers
93 views

Synthetic biology using existing cells

I was watching the video at this link: http://www.bbc.co.uk/news/science-environment-17436365 The speaker says that a cell is taken and its original DNA content is stripped out and replaced with ...
9
votes
3answers
925 views

Do men have more extreme variations than women?

This question was considered unsuitable for Skeptics and I think it is more suited to BIology than Cognitive Sciences I was reading this article which I found interesting. It is not supported with ...
3
votes
0answers
137 views

Why are trichomes important for both the roots and shoots of plants?

In what ways are trichomes vital to the plant? Why have them on the plant shoots as well?
14
votes
3answers
852 views

What causes a 'stuffy' or 'runny' nose when you have a cold?

When humans get the common cold, a common symptom is a stuffy or runny nose. Is that the body's immune response or is that the virus's doing?
9
votes
2answers
16k views

Why is SOC medium recommended for transformations?

In pretty much every transformation protocol I've seen SOC medium is used to grow the bacteria for a short while after the tranformation and before plating. I've usually substituted LB medium for ...
9
votes
1answer
560 views

What is a inhibitory tone when talking about neurons?

In this SE answer: Could an "overactive" brain increase the chances of Alzheimer's Disease? user @nico used the word inhibitory tone What does that ...
2
votes
1answer
464 views

Is Aspergillus clavatus an unicellular organism?

I could not find the piece of information form Burton Human Parasitology -book and not by Google. Yeast is divided to two phylums: one of them is Ascomycota. Aspergillus clavatus belong to the given ...
9
votes
2answers
316 views

How can I pare down a PDB file in Python to only include specific residues?

I'm trying to make a script that will take a MTZ file (reflections), convert it into a CCP4 map, then pare that map down to only encompass a desired area to cut down on the size of my PyMol session ...
12
votes
2answers
453 views

Is the 'fluttering feeling' when under stress neurological or physical?

I'm sure that everyone is familiar with the sensation commonly known as "butterflies in the stomach". It is commonly experienced during periods of anxiety or stress (e.g. before high stakes job ...
8
votes
2answers
888 views

Why are goosebumps so ineffective at keeping us warm?

If the purpose of "goosebumps" is to keep us warm, why is it so ineffective? Or are the changes subtle, but important?
8
votes
2answers
335 views

Where do the bacteria within the vagina originate from?

I understand that it's feasible the bacteria within the gastrointestinal tract originate from the food we eat and air we breath, but where does this population of microbes originate from?
11
votes
1answer
582 views

Why is the 3'UTR region highly methylated in most of the human genes?

Most of the human genes are found to be highly methylated in their 3'UTR region (0.8-0.9%). I was wondering if there is any specific reason for this?
3
votes
1answer
520 views

What are all possible vectors for unicellular human parasites?

I got the given question. They want the following pieces of information about protozoological human parasites: disease - parasite - vector. There are 10 proteogenic diseases at the Wikipedia. I ...
6
votes
1answer
117 views

On which date did the official name change of Lactobacillus sanfranciscensis change?

When did the change of official name from Lactobacillus sanfrancisco to Lactobacillus sanfranciscensis happen? An answer ((to the exact day OR within a few days) AND the name of the conference at ...
8
votes
1answer
805 views

How to clone and sequence a gene transcript of unknown sequence?

How might I go about amplifying a gene transcript (mRNA) from animal tissue of which little is known about the genome? In some applications, I have used reverse transcriptase PCR to amplify all mRNA ...
7
votes
1answer
120 views

Does the MS2 RNA binding protein have any translational repression effects?

Reposted from Quora: http://www.quora.com/Does-the-MS2-RNA-binding-protein-have-any-translational-repression-effects I'm thinking of the MS2 protein binding to its RNA hairpin target. Would the ...
4
votes
0answers
82 views

What is the distance between the 3' 18s rRNA (the Kozak consensus sequence) and the A-site of eukaryotic ribosomes during protein translation?

Reposted from Quora http://www.quora.com/What-is-the-distance-between-the-3-18s-rRNA-the-Kozak-consensus-sequence-and-the-A-site-of-eukaryotic-ribosomes-during-protein-translation The Kozak sequence ...
7
votes
1answer
7k views

What is the difference between “dikaryotic” and “heterokaryotic” states in the sexual lifecyles of fungi?

Many fungi undergo a reproductive phase in which more than one genetically distinct nuclei (from 2 separate mating types) is present within the same cytoplasm. In the Ascomycota and Basidiomycota, ...
11
votes
1answer
103 views

To which distinctions does the term “hymenoptera” refer?

Hymenoptera is an order of insects that includes bees, ants, and wasps. A quick search gives the following etymological analysis of the term hymenoptera. hymen (membrane) + pteron (wing) Does ...
13
votes
1answer
3k views

Why does Penicillin only affect bacterial cell walls

I was quite fascinated by the feature Should Science Pull the Trigger on Antiviral Drugs—That Can Blast the Common Cold? in this month's Wired magazine. They explain that Penicillin is effective at ...
15
votes
5answers
6k views

Origin, or source, of rhesus negative in human blood

This is my first post here, so please be gentle. I recently learned that I have Rh- blood (I'm A-), and was idly looking into blood types on Wikipedia. I was surprised to find that relatively few ...
7
votes
1answer
62 views

Which factors besides the thermodynamic stability are important for the hairpin in intrinsic transcription termination?

Intrinsic termination (rho-independent) relies on a stable hairpin with a subsequent uridine repeat. The common explanation on how these sequences cause the termination of the transcription are based ...
23
votes
1answer
393 views

How does a cell know its size?

Cells come in all sorts of sizes. How do they regulate their cell size to the point where similar cell types have a fairly mono-disperse size distribution? Reasked from ...
7
votes
1answer
78 views

Providing small molecules to cells on a filter plate

Lets imagine that I have mammalian cells that I've immobilized on a filter. Now I want to keep providing small molecules to these immobilized cells without resolubilizing the cells. The caveat is ...
9
votes
1answer
478 views

Do larger multicellular organisms have an increased risk of mutation and thus cancer?

So I was thinking that if each cell has P(X) of becoming cancerous, then the chance of cancer is 1-((1-P(X))^n) where n is the number of cells in the organism. Since larger organisms have more cells ...
12
votes
3answers
656 views

Is the appendix a vestigial structure in all vertebrates?

In humans the Appendix is a vestigial organ. Does it serve no apparent purpose in all the vertebrates that have one?
7
votes
1answer
406 views

How do fungi react to being grown in a tissue culture?

I know how plant cells and animal cells react to being cultured and grown this way, but what about mushrooms? Would they respond like plants, and result in embryos growing off the mass? Or does the ...
6
votes
1answer
176 views

Are there any other animals that become attached to a non-living object?

Do any animals become psychologically attached to any non-living object that is not useful to the animal for any of its physical needs, like some children do to stuffed animals? Some children are so ...
13
votes
3answers
786 views

What evolutionary explanations are there for death?

I know death and cancer doesn't hurt humans' reproductive success. It's not helping either. Why do we die? Why dying humans (all of us) are common? What's the point of dying?
8
votes
1answer
491 views

What conditions are necessary for HPL (human pancreatic lipase) to activate?

What conditions are necessary for human pancreatic lipase to activate? Is there an optimal temperature or pH? How quickly does it take effect?
9
votes
1answer
239 views

Can fruit tissue be cultured and grown independent from the plant?

Can fruit tissue be grown in a tissue culture as is done to other plant tissues? From the answer to this question, I learned that fruit is alive. Could it be possible to manufacture fruit products ...
7
votes
1answer
1k views

Can any plant regenerate missing tissue?

I have not yet found a plant that, when an insect eats a hole in one of its leaves, it can regenerate the lost tissue. Many plants will grow a new stem if the old one is cut, but it is not a perfect ...
8
votes
1answer
151 views

What do we know about LUCA?

All life on Earth (bacteria, archaea, eukarya) is thought to have evolved from a common ancestor, or last universal common ancestor (LUCA). What do we know about the characteristics of LUCA based upon ...
8
votes
1answer
221 views

How long does it take for E. coli to shift feedstocks?

With our fermentations we're noticing that it takes an appreciable amount of time for E. coli (K12 variant) to change from being metabolically streamlined on amino acids to being metabolically ...
3
votes
1answer
269 views

Predicting progeny of recessive mutations using recombination

I was asked this question on a test and got it wrong, but I'd like to know how to do it. The answers are shown in the blanks below: You are studying two recessive mutations in the fruit fly D. ...
6
votes
2answers
992 views

Basic Amino Acid Residue Binding Mechanism to DNA

I understand that many protein DNA binding domains bind to DNA via basic residues such as Arginine and Lysine. But what is the mechanism used to bind to DNA and where on the DNA would these residues ...
3
votes
1answer
9k views

Pedigree Probability of Autosomal Recessive Trait

Here is a pedigree: The trait is autosomal recessive. The question is: What is the probability that the bottom 2 people (4 and 5) have a child with the trait? I tried doing ...
10
votes
1answer
163 views

Why don't dragonflies wings collapse?

How do dragonflies manage to fly at such high speeds without their wings collapsing? Their wings are thinner than paper, but they do not even flutter. What gives them their strength?
4
votes
2answers
331 views

How do insects such as crickets circulate blood through their antennae?

Some insects, like the crickets pictured below, have such slender antennae it seems no blood could fit. How do they get blood through their antennae?
2
votes
1answer
92 views

Structure of RAP Antibodies (Specifically RAP-5)

[EDIT] - Have just found not one but two papers that address my structure problem. However they concern RAP-1A, so I guess my question is now what is the difference in structure and function of ...
9
votes
1answer
1k views

What's the effect of oxygen deficit on plants?

As I know all cells require oxygen. So my question is how efficiently can plants operate in no-oxygen atmosphere? Do all plants produce enough oxygen for themselves? Can they consume their own oxygen ...
8
votes
2answers
412 views

What does “nesting failure” mean?

According to the Wikipedia article on swans, swans are mostly monogamous but may sometimes separate, particularly after a "nesting failure". What "nesting failure" may mean is not entirely clear to ...
6
votes
1answer
88 views

Is there a tool to find the action of an enzyme in a metabolic pathway?

Is there any tool to search the biochemical action of a particular enzyme in a metabolic pathway of an organism? In other words, how can I find if enzyme "E" is involved in the metabolic pathway for ...
13
votes
2answers
611 views

Does testosterone increase female sexual behavior?

According to my lecture notes testosterone generally increases sexual behavior. Given that it's generally thought to be the male hormone I'm not quite sure whether they mean that it also increases ...
10
votes
1answer
172 views

(How) does coppicing fundamentally alter tree growth?

I am interested in adding the ability to model coppice tree production to a model of perennial crops (Miguez et al 2008).. Implementing the biomass pools and allocation parameters required for tree ...
12
votes
3answers
327 views

What is Curved DNA?

CbpA is DNA binding protein found in E. coli and binds non-specifically to curved DNA (Cosgriff et al., 2010), when the bacterium is in a static phase of growth. The use of "curved DNA" confuses me. ...
8
votes
1answer
3k views

Why does Rigor Mortis occur after death?

After someone dies they become stiff, this is termed Rigor Mortis and happens because the cells run out of ATP (I think). But why do the cells need it to remain flexible?

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