All Questions

1
vote
1answer
86 views

Could someone Identify this Insect Hive on my Balcony Grill

A smallish insect hive has been forming on the grill of my balcony in the last month or two, and I wanted to know should I be worried or can I just let it be. Its 13th floor in Singapore, if the ...
1
vote
2answers
112 views

Which was the last significant event in human evolution? What's next?

At 10.000 BC (12 ka), we became the last of the Homo species on Earth. In evolutionary terms this is a very little time range to something happen, but I'm wondering anyway, in this meantime which are ...
1
vote
1answer
618 views

Why do different humans look different?

Although farmers appear to be able to tell their cows apart, cows look very much alike to me. And this similarity in appearance seems to be a general trail across the animal kingdom: one individual of ...
1
vote
1answer
69 views

Plastid and mitochondria

I am not biologist, so please bear with me for this basic question. Although I tried googling, I am confused. What is difference between plastid, chloroplast and mitochondria? Are there any plant ...
1
vote
2answers
68 views

Epithelial cells and Rhinovirus

If you injected a tumor with epithelial cells infected with the Rhinovirus, would this still evoke an immune response as it would with the respiratory system? Secondly, what is the specific reason the ...
1
vote
1answer
56 views

What cell types produce immunoglobins and where are those cells found?

I know B cells found in bone marrow produce immunoglobin G. But IgM is produced in mucosal cells at least in the gut. Can you find immunoglobin expressing cells in other tissues in the human body? ...
1
vote
1answer
143 views

Birds and Dinosaurs

This came up in an argument with some friends. I know that birds are direct descendants of dinosaurs, shown pretty clearly through the fossil record. However, is it proper to say that birds are ...
1
vote
1answer
157 views

List of all reported bacteria

I would like to know were to download a table file with all reported bacteria and its corresponding PHYLUM, CLASS, ORDER and FAMILY. Basically, its the same table than this one from GOLD genomes but ...
1
vote
1answer
108 views

Do spouses begin to share genes over time?

I apologize if this hypothesis sounds strange by I was wondering if any research had been done on a phenomenon which I've seen and have corroborated with many other - the idea that over time spouses ...
1
vote
2answers
41 views

Which part of the genome are the developmental sequences of embryogenesis located?

Which part or parts of the the genome are the sequences located. Are they spread across the chromosomes? If so how are they accessed sequentially with precision during embrygenesis?
1
vote
1answer
961 views

Why do I always close my eyes when someone takes a photo of me using a flash?

Everytime some tries to take a photo of me with a flash I manage to close my eyes (blink). It's not intentional and it's quite annoying. Why am I doing it?
1
vote
1answer
121 views

Why are some fungi poisonous?

There are many poisonous fungi in nature. For example Amanita Phalloides. What reasons could a fungus need poison for? Some species, like venomous snakes, use poison to kill other species as prey. ...
1
vote
1answer
3k views

How are the paranasal sinuses linked with the capillaries in the ear canals?

Sinus congestion often seems to be accompanied by excess pressure on the outer ears (as anyone who has shared a transcontinental flight with an infant can attest to) or fluid buildup in the canals. ...
1
vote
1answer
85 views

Identification of this insect?

I noticed several of these guys outside, all in a vertical position clinging to a wall. I didn't come to them too closely, but my immediate reaction was that they are scorpions. I thought that ...
1
vote
3answers
126 views

What kind of arthropod/animal is this?

Can anyone identify this strange creature? I live in a very urban part of Montreal, Canada. It wasn't moving (seemed dead) and although the image is huge, it wasn't as big as it seems (a couple of ...
1
vote
1answer
50 views

Are there neuronal firing artifacts produced by head movement?

I'm experimenting with a consumer-grade ElectroEncephaloGram (EEG) sensor and have created the image below using the device. Because the sensor on the device does not use a suction cup, there are a ...
1
vote
1answer
144 views

What's the Evolutionary Purpose of Religion? [closed]

I would imagine the answer to this question would be that religion tends to cause greater compliance of individuals within society, so it is pro-society. Plus these religions tend to incorporate some ...
1
vote
2answers
2k views

Restriction Mapping of Plasmid Assignment

pUWL22 is a circular, double stranded, 10.5 kb plasmid. It contains a gene encoding an enzyme that confers ampicillin resistance in the host bacterium. Cloning into the kpn I and Sst I sites ...
1
vote
1answer
576 views

Why do plants have pith and how is it useful to them?

Many plants have pith, from walnut trees to corn to ragweed, but I can't think of anything it does them. What is pith and how is it useful to them?
1
vote
2answers
47 views

How does high-fidelity of DNA replication depend on the formation of hydrogen bonds?

Replication has an error rate of less than 1 in 100 million. DNA polymerase forms H-bond with the H-bond acceptor atoms in the minor groove. <-- enhance fidelity here? Binding of the triphosphate ...
1
vote
1answer
39 views

What are the risks of elevating the legs too regularly and when tired?

I started to to think the pathophysiology of elevating legs high next to the wall too often and when you are tired. I think possible manifestations some damage to valves of the veins (No!) because ...
1
vote
2answers
34 views

Incomplete Dominance and Probability

I have a follow-up question about an in-lecture question (this is not a homework question). As you can see I have already answered the question and the question is closed to further submissions. ...
1
vote
1answer
65 views

Evolution, What would the first plants have been like?

I am curious what the first plants are thought to have been like, what they may have evolved from, and how much earlier (or later) than animals they are thought to have moved to land, if they even ...
1
vote
1answer
24 views

How does fluorouracil inhibit pyrimidine synthesis?

I was reading in my pharmacology textbook about fluorouracil, and my book mentioned that fluorouracil is an antimetabolite whose function is to inhibit pyrimidine synthesis. However, I was curious to ...
1
vote
1answer
60 views

Why are hard boiled eggs so homogeneous?

A eukaryotic animal cell is a complicated piece of biological machinery. Some major structures inside of the cell (see the image below) include: the nucleus, mitochondria, Golgi vesicles, and various ...
1
vote
1answer
46 views

Can mosquitos bite in self-defense?

When chasing away wasps or bees thee is a danger of them stinging us in self-defense. Can a similar danger arise when chasing away a mosquito which is otherwise not hungry? I understand that ...
1
vote
2answers
103 views

Is greed an evolved trait?

Thanks for looking. I am not a biologist, but I am fascinated by evolution. I was watching the news this morning and, as so often is the case, there was a news story about a corrupt politician who ...
1
vote
1answer
39 views

Applying drugs to brain via scalp (transdermal)

Many medications are intended only for the brain, but are taken orally. Hence <10% finds its intended target, while the remaining >90% is at best wasted, and at worst causes unwanted side-effects. ...
1
vote
1answer
65 views

How to estimate the DNA density in human sperm head? [closed]

I have got an estimate of sperm head volume from internet.Like consider it as a disk of order 4-5µm. Now I wanted to find the DNA density in the sperm head. How to find that?
1
vote
1answer
37 views

Gastro-intestinal physiology reference

I am a physicist but I have always wanted to understand how my digestion takes place in as much detail as possible. I have no idea about books or reference on the subject of Gastro-intestinal and ...
1
vote
1answer
47 views

What are the dimensions in angstrom of bacteria? [closed]

I'm going to take a picture of a bacteria but I am unsure how large it is. What are the dimensions in angstrom of bacteria?
1
vote
1answer
63 views

Is the human collarbone supposed to break?

I've read it in a book and have heard people mention it, but I can't find any documentation about it. But the point being made is this: The human collarbone acts as a shock absorber for impact on ...
1
vote
2answers
52 views

How to know if your breathing is normal?

Is it possible for a device to measure how much air we breathe in and out over the entire day and at what rate? I think if we have access to this data we can compare it across people.
1
vote
1answer
39 views

How long does it take for a cell to synthesize an enzyme?

Where can I find data regarding the times distinct cells take to synthesize distinct enzymes?
1
vote
1answer
57 views

Is it possible for neurons themselves to manifest cancerous behavior?

From what I understand, one form of cancer is a faulty gene responsible for the programmed death of a cell. Not long ago, popular wisdom used to say neurons don't regenerate. However that is no ...
1
vote
2answers
49 views

Useful physical information of a protein

Beside energy and heat, I don't know any useful physical information of a protein. Can you help me list some of it. Somethings like Fourier-transform infrared spectroscopy to provide protein structure ...
1
vote
1answer
67 views

Meaning of “auto” in trans autophosphorylation?

Why this process called "auto"? Is it because each tyrosine kinase receptor subunit of the RTK dimer has the ability to phosphorylate tyrosine or other amino acid residue present in other subunit of ...
1
vote
1answer
215 views

What is the difference between these terms: clade, monophyletic group and taxon?

Wikipedia definitions for these terms are pretty similar: http://en.wikipedia.org/wiki/Clade http://en.wikipedia.org/wiki/Monophyletic_group http://en.wikipedia.org/wiki/Taxon They sound like the ...
1
vote
2answers
79 views

problem with natural selection [duplicate]

I fail to see how natural selection can build any kind of new functionality. New functionality in a design requires sacrificing a complex series of meanwhile useless steps before the new ...
1
vote
1answer
73 views

A question related to qPCR analysis

Here is the thing. I am using a method, called TU-Tagging, to isolate cell type specific RNA. You can find more about the method here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2783170/ To explain ...
1
vote
2answers
85 views

Gene perturbation, what is it used for, explain to computer scientists? [closed]

I am trying to build a gene regulation network, and I need some basic knowledge of it. So, in gene research, we perturb genes. Such as knock down them? Can people tell 2 or 3 experiment methods to ...
1
vote
1answer
87 views

Biology in romantic love

Hi could anyone explain the biological basis behind romantic love. What is the biological basis of falling in love?I know that serotonin and dopamine are secreted when we first fall in love. What ...
1
vote
1answer
76 views

What is the current molecular explanation of Mendel's pea cross?

With reference to the simplest Punnet square for Mendel's pea plant experiments it occurred to me that I could not connect the little I know about genetics to the little I know about molecules. The ...
1
vote
2answers
56 views

Which types of hydrogen bonds are known to exist in RNA secondary structures?

I'm programming an implementation of an algorithm for pattern matching in RNA structures. The algorithm assumes the following types of base pairs: Plain: No base pairs (just the primary structure of ...
1
vote
1answer
95 views

What kind of small insect is this?

Found in central florida in the bath tub. Its about the size of a pencil marking, very small. What is it?
1
vote
2answers
60 views

Book recommendations for evolutionary models

I was recently working on getting a statistical model of a DNA sequence. To do this I found that understanding evolution quantitatively seems to be quite important. I would really appreciate any book ...
1
vote
2answers
89 views

Effect on fitness of mutations

What is the distribution/probability density function (PDF) of impacts on fitness of new mutations? I very welcome any partial answer that does not give the whole PDF but just some information ...
1
vote
1answer
91 views

What is the biological reason that some viruses cause sore joints (eg flu)?

Frequently I have experienced sore joints during a bad bout of influenza. I understand that during time of sickness, white blood cells are deployed in the blood stream. I also believe that white blood ...
1
vote
1answer
221 views

Why does ear wax taste sour?

Why does ear wax taste sour? I am interested in both the physiochemical mechanisms and the evolutionary reasons behind the sour taste of earwax.
1
vote
1answer
53 views

Buy bacteria for experiment?

Where can I buy paracoccus denitrificans? I need it for an experiment. I cannot find online where I can purchase this.

15 30 50 per page