3
votes
1answer
74 views

How do we memorize something?

When we see something, how and where in the brain do we remember it and are able to recognize it later? What happens in the brain that makes this possible?
3
votes
1answer
1k views

What biological constraints are there on how large a spider can grow?

Spiders fascinate me, but what intrigues me the most is just how big some spiders can get, which leads me to my question. What biological constraints (if any) would limit how large a spider could ...
3
votes
3answers
1k views

Polymorphism in cnidarians?

To me, the phenomenon of polymorphism in cnidarians is particularly troubling. I gather that it essentially refers to existence of various different forms or kinds of individuals, i.e. zooids and ...
3
votes
3answers
1k views

Histidine aromaticity

I understand that the imidazole ring in histidine is aromatic. I also realize that it retains it's aromaticity when protonated. I am wondering why it is not mentioned at all in basic text books such ...
3
votes
1answer
77 views

Can I use PCR buffer instead of cDNA synthesis buffer?

I am using Fermentase First strand cDNA synthesis kit but its buffer is over. I need to work today but I have not access to any sorce currently. I have PCR buffer in the lab. Can I use PCR buffer ...
3
votes
3answers
80 views

When can I assume individuals marrying into a pedigree are non-carriers?

If I'm not told that they're non carriers, and if I don't have proof of their geneotype based off of progeny, when can I assume they're non carriers for a trait?
3
votes
2answers
69 views

How common is bacterial mediated transformation? In plants? In animal cells?

The most common method to transform plants is by soaking plant tissue in cultures of agrobacteria (this is not their current classification) which transfer DNA into the plants. Is lateral gene ...
3
votes
2answers
920 views

Why do some animals have 8 Limbs (e.g. Spiders, Octopuses)?

Octopuses have 8 tentacles, spiders have 8 legs. Is there something special about 8? It seems like an animal that needs 360° mobility has 8 legs.
3
votes
1answer
54 views

Is copy number variation dynamic?

Is there any evidence showing that copy number variation changes over time? I'm wanting to model interactions in expression level as a dynamic bayesian network, but an assumption my approach will need ...
3
votes
2answers
101 views

How would ecology be affected if 100km² of an ocean surface was covered by a floating object?

Assume that we planted floating solar cells on the ocean surfaces. Assume a 100km² solar cell field in the middle of the Pacific Ocean. All of the sunlight will be blocked by them. How would that ...
3
votes
2answers
1k views

What is the evolutionary rationale for palm sweating?

Sweaty palms seems to be a reaction to stress, anxiety, etc. For our forest-inhabiting primate ancestors sweaty palms could cause unwanted side-effects such as slipping off tree branches under ...
3
votes
1answer
80 views

How can GMO contaminate biologic plants?

Let consider two use cases : I am the only farmer within a 200km radius. I first grow GMO plants. A few cycles later I decide to grow bio plants, so I uproot all of the GMO plants and plant fresh ...
3
votes
2answers
93 views

Have proteins been observed to come into existence through mutations and natural selection?

What is an example of a functional protein that has been observed (in real time) to have come into existence through mutations and natural selection (not through an existing one being made defective). ...
3
votes
2answers
340 views

JMol “calculate HBONDS”: which atom is the donor/acceptor?

JMol can be used to identify Hydrogen bonds in proteins by the script "calculate HBONDS". By outputting the state of the network, we can obtain a lisdt of H-bonds. Here's one line from an example ...
3
votes
2answers
305 views

Two subunits connected by only one disulfide bridge: quaternary structure?

I've always simply assumed quaternary structure to be characterized by non-covalent interactions such as hydrogen bonding, van der Waals interactions and whatnot. However, if two distinct polypeptides ...
3
votes
2answers
346 views

Why do plants' leaves become enlarged in low light areas?

Why do almost all plants in shade have a smaller stem structure and larger leaf than that same species grown in a well lit, sunny area?
3
votes
2answers
327 views

Do all Gram negative bacteria cause septic shock?

Do all Gram negative bacteria cause septic shock? If they don't could they if you attacked them with an antibiotic that could lyse the cell? For example any antibiotic that attacks the cell wall, ...
3
votes
3answers
208 views

Where does crop biomass come from?

Each year, large volumes of crop are harvested from fields. Where does this biomass get replenished from?
3
votes
2answers
49 views

How did aquatic dinosaurs go extinct?

Dominant theory is that 'normal' dinosaurs went extinct from ether super volcano or meteor impact or combination of both. However there were aquatic dinosaurs that are not present at this day. Was it ...
3
votes
3answers
326 views

What is the difference between eugenics and evolution by natural selection?

So with the working definition of Eugenics: "the aim to improve the human gene pool". What are key features that distinguish Eugenics from evolution by natural selection? I mean, besides that natural ...
3
votes
2answers
64 views

Proteins with alpha helices alone and beta sheets alone?

I would like to see some examples of proteins with PDB ID so that I can download and see them in VMD software. I need some proteins with alpha helix only and proteins with beta sheets alone.
3
votes
1answer
57 views

About sharks and how they find fish

Other than olfactory senses do sharks use some kind of sense that uses electromagnetic waves? Is this similar to an electric eel? I saw a book with the cover statement 'Sharks never get cancer'. IS ...
3
votes
1answer
36 views

Why is Psoriasis treated with Cortisone, when stress (which releases Cortisol) is known to aggravate the condition?

It is well known that stress isn't good for psoriasis , yet why do we treat the illness with Cortisone, a compound very similar to cortisol (and "has a similar name, genesis, and function", according ...
3
votes
1answer
36 views

Drugs metabolism and detection

If someone is taking treatment for a psychiatric disorder, for example diazepine, would traces of the metabolized drug show in their sweat or saliva? Would it be chemically detectable?Any links to ...
3
votes
1answer
59 views

Why do birds move their heads abruptly?

When we humans look around, we pan smoothly from one side to the other. Birds on the other hand seem to point their head in one direction for a while, then abruptly point their head in another ...
3
votes
1answer
72 views

XXY (Klinefelter's) & Trisomy 21 & X-inactivation

I read that X-inactivation doesn't tend to happen in males, but then when someone is XXY, they are a male because of the Y. However these individuals tend to live. So does that mean that ...
3
votes
2answers
59 views

EM Brainwaves VS Brain Wave (EEG) [closed]

The brain purportedly produces very weak EM waves. EEG is a method of measuring electrical brain activity, it has classifications for the types of brain wave it can detect: Theta, Alpha, Beta, Gamma ...
3
votes
1answer
104 views

The smell from eating asparagus

I am wondering about one thing. I have read different accounts of this (prior to reading it on Wikipedia), so I am wondering. Here are the two versions I have read: asparagus leads in a certain ...
3
votes
2answers
88 views

Convergent evolution of fruits

Many fruits are not homologous, originating from different parts of a plant. Yet they all have similar properties: Ripe fruits all have yellow to dark red color They all have a lot of water and ...
3
votes
1answer
49 views

Why don't animals produce alcohol

As I understand during anaerobic respiration, the electrons received from the decomposition of glucose are transferred to nicotinamide adenine dinucleotide and flavin adenine dinucleotide. As there is ...
3
votes
2answers
643 views

Essential amino acid codons

Essential amino acids also have codons.Still they are needed by humans through diet?Will those codons do synthesize amino acids for some other purposes in humans or not?If so, what is the purpose?e.g? ...
3
votes
1answer
47 views

When infected with malaria, how many parasites are within a human host?

When infected with malaria, how many P. falciparum cells are within a human host? And how does this compare with the average infection parasitemia of A. gambiae? I can't seem to find a reliable source ...
3
votes
1answer
135 views

How do GPCRs transmit a signal across the plasma membrane?

How do G-coupled protein receptors (GPCR) transmit signals through the plasma membrane? Links containing information about this and pictures will be very helpful.
3
votes
1answer
55 views

Pharmacology Half Life Calculation

I'm really stuck on this question. I'm being asked to find the half life of a drug. The Vd is 50L/kg. The clearance is 0.1 L/hr/kg. The patient weighs 70 kg. Equation is: T1/2 (halflife) = 0.693 * ...
3
votes
2answers
67 views

Cancer growth and cell division [closed]

I am confused about the prerequisites for cell division and cancer. Which of the following is necessary for the cell cycle to progress? Hormones Growth factor Cyclins Cyclin dependent kinases ...
3
votes
2answers
83 views

Is there an evolutionary explanation for the black spots around a pandas eyes?

I couldn't seem to find one elsewhere, at least not with a scientific source. It would seem as it's quite a striking feature there would be an advantage it would infer.
3
votes
1answer
122 views

Do there exist publicly available Genome sequences of a family?

I would like to explore the genome sequence of a publicly available genome sequences of a family (like mother, father, son, daughter...). If such human genome sequences are not publicly available at ...
3
votes
2answers
125 views

What are the factors that control the speed of propagation of neuronal signals?

If we consider an analogy between a wire and a neuron there may be some resemblance between the factors controlling the data flow rate. For example the increased width of wire leads to decreased ...
3
votes
1answer
652 views

What is the proper format for genus and species names in latin?

When using the latin nomenclature for a fish in printed materials (such as Sander vitreus for walleye), what is the correct capitalization of each word? In this example, should 'S' be uppercase ...
3
votes
1answer
131 views

Why do cockroaches burst from soapy water?

(careful, disturbing!) I was experimenting with some stray cockroaches that ended up falling in my bath tub overnight (there is currently an infestation undergoing in my apartment building) and I ...
3
votes
1answer
43 views

How does tree resin capture arthropods?

In regards to a published paper of a spider about to make a meal out of a parasitic wasp (http://www.tandfonline.com/doi/abs/10.1080/08912963.2011.640399#.U1kSV14gVBU), it reminded me of a issue I've ...
3
votes
1answer
67 views

Do people with gout live longer?

Antioxidants reduce damage to tissue (by scavenging the free radicals) and thus may reduce ageing.It is known that Uric acid is a very good antioxidant. People with gout have excess accumulation of ...
3
votes
1answer
50 views

Function of heparin and dextran sulfate for removing proteins

From this article : The reaction was terminated and the histones, and most nonhistones, were removed by adding the nuclease-treated chromosomes to a solution containing dextran sulfate (2 ...
3
votes
1answer
25 views

Changing time and rpm of centifuge

Inspired by this question, I want to ask a question about centrifugation. Suppose a protocol says : 10 min at 2500 rpm . Can we instead centifuge for 5 min at 5000 rpm or 20 min at 1250 rpm ?
3
votes
1answer
209 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 ...
3
votes
2answers
145 views

Can diploidy evolve in absence of sexual reproduction?

Theoretical question Can diploidy (or polyploidy) evolve from a haploid lineage in the absence of sexual reproduction ? For what theoretical reason? How can such evolution take place? Empirical ...
3
votes
2answers
68 views

Detecting cancer or a genetic predisposition based on DNA sequencing

I am not by any means a biologist - so go easy. What would be a method for determining whether or not a patient has cancer based only on a genomic sequence? Update Thanks for the help in revising ...
3
votes
2answers
127 views

Question about Autosomal Recessive Alleles

I had a homework question that I could not figure out. It states: A woman has cystic fibrosis in her family and did not want to have a child that suffered from the disease. She and her spouse ...
3
votes
1answer
35 views

When was it determined that Type 1 Diabetes is an autoimmune disease?

I just found out today that type 1 diabetes is an autoimmune disease. When was this discovered?
3
votes
3answers
115 views

Can humans be printed?

Is it possible to spray stem cells on fully grown skeleton to get fully grown humans? Currently, just read about recent advances, and wondered if something like this is possible.

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