3
votes
1answer
142 views

Identification of this fly?

So I find these flies every year in my mulch, and I've never seen them anywhere else. The mulch becomes full of their larvae, which I feed to my toad and lizards. There are so many that you can hear ...
3
votes
1answer
331 views

What hair color will result in someone inheriting both blond and ginger genes?

Both the genes for blond hair and ginger hair are recessive, so they need both parents to give the same gene for it to take affect. What happens when a person has 1 copy of a recessive gene and ...
3
votes
1answer
126 views

Are similar smells usually based on similar chemicals?

Building off of this question: Why does freshly cut grass smell like a watermelon?, is it usually the case that things that we perceive as having similar smells are, in fact, the same or a similar ...
3
votes
1answer
115 views

Do insects respond to the detection of dead insects?

Are there insects that change their behavior upon detecting the nearby presence of other dead insects? If there are, can you provide an example?
3
votes
1answer
120 views

Are any organisms known to use meiosis I to create non-identical offspring asexually?

So, there are numerous species of animals who use parthenogenesis, but to my knowledge the reproduction is clonal. That is, the offspring are identical to the mother. Are there any documented cases ...
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
220 views

Macroevolution vs. microevolution

Where is the line usually drawn between macroevolution and microevolution? I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes ...
3
votes
1answer
146 views

What kind of caterpillar is this?

I've made a photo using the reversed 58 mm lens and my cropped DSLR: Could you please help? I really don't know where this came from. I found it in Russia.
3
votes
2answers
102 views

Do dolphins really sleep?

I have always wondered, if dolphins sleep with one eye opened, do they really sleep at all? According to this article dolphins indeed shut down their brains. I already googled it. No help from ...
3
votes
2answers
82 views

Is there a way to measure the amount of bytes that are possible to encode in a DNA molecule?

When I saw a DNA molecule for the first time, it kinda reminded me of a hard drive. It consists of slots and there are some possible combinations for each slot; in the hard drive these possible ...
3
votes
2answers
514 views

Why does Glutamine have the symbol Q?

Spent a half hour googling this and the best I could find was this: Now for some rhymes: Arginine = R. R we having fun yet? Asparagine = N The kNights of Ne say "Ne". Glutamine is a cute ...
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
296 views

How are melatonin levels measured in humans?

I'm wondering how it is possible to measure diurnal variations of melatonin levels in humans. I keep reading that there should be a large difference in amplitude between melatonin levels measured at ...
3
votes
2answers
330 views

Why is the frog genome so much larger than a fish's?

As we have heard in the summaries of the human ENCODE project, 80 per cent of junk DNA appears to have an essential function. Many fish have a genome with only one tenth the size of a usual vertebrate ...
3
votes
3answers
6k views

Evolutionarily speaking, why do humans have 46 chromosomes

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Monkeys, chimpanzees, and Apes have 24 pairs (twenty-four pairs), for a total of 48. What caused humans to have 46? ...
3
votes
4answers
1k views

Can the third sex be categorized as Male or Female?

Hijra are people who have a penis (not sure if sexually active) but look much like a female (perhaps for some feminine biological property). Wikipedia says they are "physiological males who have ...
3
votes
0answers
117 views

What controls the feeling of discomfort/comfort before and after sleep?

I'm interested in which biological systems or hormones are involved in the following phenomenon: Before sleep it may be difficult to find a comfortable position, and muscular aches and pains are more ...
3
votes
1answer
433 views

Could inhibition of progerin formation slow the rate at which a body ages?

According to wikipedia, progerin is activated in senescent cells. The protein itself is known to be the cause of a rare affliction 'progeria' - a disease marked by accelerated aging of the body. This ...
3
votes
2answers
355 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
1answer
1k views

Is secondary follicle or Graafian follicle arrested in the second metaphase of oogenesis?

My note about which I am not sure: Secondary oocyte is arrested in the metaphase II monthly after puberty until fertilization with sperm. The following picture also satisfies my sentence: . So ...
2
votes
1answer
56 views

What percentage of DNA do people share?

If you picked two people in the world at random, sequenced each of their entire genome, and compared their DNA, what would the expected percentage match be?
2
votes
1answer
27 views

Transcription rate expressed in microarray per hour

This article gives measurement of transcription rate and the unit they're using is microarray per hour. For example, at 27°C the average expression of their genes is 236.1 microarray per hour (page ...
2
votes
1answer
60 views

Pectinase Enzyme Assay

I am working on pectinase enzyme assay. I incubated 900 ul of substrate for 10 minutes in the water bath, followed by adding 2ml of DNSA reagent, then 100ul of enzyme extract added finally i read the ...
2
votes
1answer
68 views

Why does a housecat (or other predator) play with it's food before killing and eating it? Does it make the food taste better?

I've read a couple people theorize that a cat playing with a mouse causes the mouse's body to be flushed with adrenaline before the final kill and that this adrenaline makes the meat more ...
2
votes
1answer
75 views

Can I identify this black ant queen?

I have an ant queen in a jar. This is what she looks like: Because I'm planning to start an artificial ant nest, I'd like to learn something about that specific species of ant. This particular ...
2
votes
1answer
43 views

Do Ants have a sense of Direction?

Do ants understand which way is up or down? Could they differentiate between uphill and downhill?
2
votes
1answer
132 views

Anaerobic respiration choice in E. coli

Under anaerobic conditions E. coli has two options to generate ATP: fermentation (substrate-level phosphorylation), and respiration (proton gradient, chemisomotic phosphorylation). Which is favored? ...
2
votes
2answers
187 views

Is this statement in agreement with Darwin's theory of evolution?

Is the following statement in agreement with Darwin's theory of evolution? The number of offspring is not related to fitness. If so, why? This is not a homework assignment, I just want to ...
2
votes
1answer
928 views

Why do three nucleotides code for one amino acid? Why not 5 nucleotides? [duplicate]

We all know why there are 3-base codons, and why there aren't any 2-base codons. But why is there not a 4-base a 5-base codon?
2
votes
1answer
127 views

What insect is this..?

Can anyone tell me what kind of insect (if it is one) is this...!! Or is it the pupa of some insect? Well I don't think that the whole big thing is the insect itself, it appears to be just a kind of ...
2
votes
1answer
28 views

Can animals absorb atmospheric sulfur?

This is a follow up to this previous question: In biosynthesis of cysteine and methionine, where does the sulfur come from? Can animals use gaesous H2S in the atmosphere, say for instance from a ...
2
votes
1answer
60 views

Evolution from Mating types to different sexes

Imagine a lineage of multicellular organisms that had mating types and evolved their mating types into sexes. What are the possible mechanisms that might have brought this lineage to evolve sexes from ...
2
votes
1answer
1k views

Isopropanol precipitation of DNA - duration and magnitude of cold storage

DNA prep protocols often include a final precipitation step with alcohol, often isopropanol, where the DNA must be kept in the alcohol, at a low temperature such as -20C or -70C, often overnight. ...
2
votes
1answer
62 views

How usable is the Human Metabolic Model to predict biomass?

In order to use the Human Metabolic Model for Flux Balance Analysis of specific cancer cell lines, we would like to know what sort of flux values have been determined for the Human Metabolic Model. ...
2
votes
2answers
94 views

Why do people use anti-inflammatory drugs?

Why people should take anti-inflammatory drugs, when inflammation is a physiological way to defend our organism?
2
votes
1answer
197 views

Why do genetic drift generates negative linkage disequilibrium?

The very first sentence of the abstract of this article are: "In finite populations subject to selection, genetic drift generates negative linkage disequilibrium, on average, even if selection ...
2
votes
2answers
531 views

Are there genetic similarity between humans and pigs that don't exist in chimps?

Chimps are our closer relative. Any genetic similarity between humans and chimps must exist on the common ancestor. Pig branch out sooner. So, any genetic similarity between humans and pigs must be ...
2
votes
3answers
179 views

Mechanical cause of loss of consciousness

Consciousness is an electrical and chemical interaction in the brain, caused by neurons firing and chemical interactions. How does a mechanical "force" cause this to stop working? i.e. How does a ...
2
votes
1answer
635 views

Why does freshly cut grass smell like a watermelon?

I found that, when I smell watermelon aroma outdoors, someone nearby has mowed the grass. Is there an underlying basis?
2
votes
2answers
188 views

A source for leaf architecture of different plant species/genus?

I'm currently working on extracting some features of the leaf architecture based on their images (like L:W ratio, laminar shape, ...). I use the Manual of Leaf Architecture as the reference. It is ...
2
votes
0answers
111 views

Good poly-A filtering rules or tools

I am aligning a large number of ESTs. It seems poly-A tails show in many different ways. In addition to occurring at the very end, they can be flanked by the cloning sequence one one end, or have ...
2
votes
1answer
453 views

What is the relationship between UV wavelength and penetration depth into human skin?

Some background - Some recent research has strongly suggested that UVA penetration into the skin is far more dangerous than UVB, a very good example is this paper by Agar et al. (2004). My query is, ...
2
votes
2answers
385 views

Transcription factor binding site located in intron

I have noticed that some TF binding sites are located in the introns of the genes. I am puzzled about whether the TF only binds to DNA in the initiation stage of transcription and will detach during ...
2
votes
1answer
251 views

What is this insect?

These photographs were taken today in Marseille, in the Mediterranean coast of France. My French friends inform me that these beasties are called cousins because they are "cousins" of mosquitoes ...
2
votes
2answers
873 views

What is in the space between neurons in a brain?

When neuron animations are displayed, there are frequently seen neurons, axons arranged in a lattice with a lot of empty space between. I'm interested if there is indeed empty space in the brain, or ...
2
votes
1answer
115 views

Why is elevated homocysteine considered a risk factor for angina?

Elevated homocysteine levels are listed among risk factors for angina. How is homocysteine related to the heart? Or the coronary arteries? How do these relationships make it a risk factor for angina? ...
2
votes
2answers
45 views

Can stress echocardiography show coronary blood flow difference before and after exercise?

Stress echocardiography means a pair of cardiac ultrasound imaging examinations, before and after exercise. I assume that coronary blood flow is increased after exercise. Is cardiac ultrasound ...
2
votes
2answers
387 views

What would it take to recognize a deer by its photo?

I am trying to recognize a deer by its antlers or any other means. Elaborating: I was hoping to use their antlers to recognize them but I have heard that most deers shed their antlers every year so ...
2
votes
2answers
491 views

Iron deficiency anemia symptoms explanation

In my classes and on the internet, brittle nails and dry hair (or hair loss) are described as symptoms of iron deficiency anemia, but none explains the cause of such symptoms. Does anyone have any ...
2
votes
1answer
89 views

Confusion related to a term probe-by-background interaction

I was reading a paper related to bioinformatics where it uses the drug response on the cancer cells and the gene expression of the individual cells are studied to find any useful insights. Specially, ...

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