2
votes
0answers
51 views

Natural selection and the Galapagos Islands [closed]

Woodpeckers found on the South American mainland are able to peck insects from the bark of trees. Would the woodpecker finch have been able to survive if woodpeckers had found their way to the ...
1
vote
2answers
4k views

Why is weight gain a symptom of Cushing's Syndrome?

Cushing's syndrome results from increased levels of cortisol in the body. Cortisol as I understand it however, promotes the breakdown of glycogen and amino-acids in the process of gluconeogenesis, to ...
2
votes
1answer
52 views

Fusion of neuron with a S phase cell

There was some experiment in which a S phase cell was fused with other cell and the other cell also began to replicate DNA. Would the same happen if fused with nerve cell ? Why or why not?
1
vote
1answer
102 views

Why would the Camargue horses have a white coat while the foal have a dark coat?

The current issue of the magazine Lonely Planet India(Oct 2013) presents a photo of Camargue Horses which are white coated and mentions that they are born with dark hair. A search shows that the foal ...
5
votes
1answer
142 views

Synthetic construct with multiple ORFs not expressing

I designed a synthetic construct on paper and got it synthesized from a company. The objective was to make a vector which can be used to study both transcriptional and post-transcriptional regulation ...
3
votes
1answer
411 views

Is there an optimal composition and length for protein linkers in FRET?

I'm designing a protein that I'd like to use in FRET reporting. General idea on the shape is: FRETprotein1--Linker--CleavageSite--Linker--FRETprotein2. I would like to know what AA are best for the ...
4
votes
3answers
408 views

What are the benefits of elucidating the crystal structure of a protein?

I have spent months as a student working on trying to form a tricky protein crystal. But I have never actual had explained to me why the structure will be useful. Once elucidated, what can we ...
3
votes
1answer
82 views

Will a garter snake eat unusual prey if made to smell like something normal?

I have noticed that my garter snake only eats after it has smelled it's prey to make sure it is a slug, and it doesn't matter whether it's moving or not. If I were to coat, say, a caterpillar with ...
2
votes
0answers
322 views

Distinguishing between mitotic metaphase and metaphase II of meiosis

I'm sorry if this seems like a silly question, but I was brushing up on some cell cycle dynamics and realized that everyone was talking about the differences between metaphase I and II, and since ...
6
votes
5answers
1k views

Why do most mammals have long snouts?

It seems like most mammals, e.g. dogs, have long snouts. My pet dog's snout would seem to me like an evolutionary disadvantage, since her canine teeth are way out at the end of her jaw, which acts as ...
0
votes
1answer
118 views

The probability of indirect human fertilization (follow-up)

This question is a follow-up to this one. I've been wondering how small that probability is. As we all know, "safe" sex, that is (correctly) using a condom and all that, isn't perfectly safe. So, in ...
3
votes
3answers
2k views

What if rB=C in hamilton's rule?

Hamilton's rule states that if rB>C then a gene giving altruistic behaviour will increase in frequency in the population. What would happen if rB=C? Will an individual perform the altruistic act?
6
votes
1answer
61 views

Is telomere shortening consistant over consecutive cell divisions from zygote to a differentiated cell?

Considering the complexity of embryogenesis, a temporal referance would be helpful to coordinate the developmental sequences during embryogenesis and fetal development which is to be completed within ...
7
votes
1answer
606 views

Yellow/Orange Fungus on Oak Tree

What is the fungus pictured below? The photo was taken October 6, 2013 near San Antonio, TX. I have Googled it and my results suggest Laetiporus root rot (Laetiporus sulfureus). According to this ...
6
votes
1answer
163 views

Puffball mushroom species ID?

Found this mushroom today. It's a kind of puffball mushroom and I think pestle puffball but I hope someone can confirm that/point me to other likely species. It was in Central Eastern Sweden ...
5
votes
1answer
915 views

Why do organisms excrete nitrogenous wastes?

All plants and animals excrete nitrogenous wastes in the form of urea, uric acid or ammonia. But isn't that a bit of a waste? I mean, there is a shortage of biologically available oxygen in the ...
0
votes
1answer
81 views

Is there already discovered non-carbon form of life?

I have heard of some rumors going around about a living organism based on non-carbon. Is Has research been done with real form of life based on non-carbon? Or carbon-based life is only type of life ...
4
votes
1answer
110 views

Identify this spider

I found this spider on my balcony in Sunnyvale, CA. It sat in a irregular net. The body was approx. 6mm long. Which species does it belong to?
-4
votes
1answer
84 views

Would I still exist if [closed]

I've been wondering for some time, but say that my mother's egg chose another sperm cell, and a baby was eventually produced. Would I still be born, but end up with different characteristics/features? ...
9
votes
2answers
15k views

Is it possible for a brown eyed parent to have blue eyed child?

Here's the story: A young man has stunning blue eyes. On his mother's side are lots of instances of blue eyes, but on his father's side is no history of blue eyes. When he was born with these bright ...
1
vote
3answers
1k views

Does Darwin's Theory of Evolution refute Terence McKenna theory “Stoned Ape” theory of human evolution?

I haven't read it but I'm asking for a quick answer. As far as I know, Terence McKenna's theory of evolution in humans main concept is that a hominid has tried in their diet psilocybin mushrooms, and ...
7
votes
3answers
6k views

Does our DNA change during our lives?

As far as I know, DNA is the construction protocol of all organisms on Earth. Does it change when influenced by time and environment (physical laws)? As parents with schizophrenia are more likely to ...
2
votes
2answers
412 views

The antibiotic 'kanamycin' in the growing of culture E. coli

I'm a first year student and I'm not sure if I understand correctly the role played by the antibiotic 'kanamycin' in the growing of culture E. coli (Rosetta). Can anybody explain me why we use ...
2
votes
2answers
403 views

How is RNA of retrovirus converted into cDNA?

The retrovirus (oncovirus) contains RNA. It also has a molecule called reverse transcriptase. This molecule transcribes RNA into cDNA. This cDNA is the DNA copy of viral RNA genome RNA has Uracil ...
4
votes
3answers
2k views

What is the equivalent of shutter-speed in Human eye?

I just learned that in video cameras, every frame of the video has its own shutter speed. And I know how frame-rate in human eye works out, well, not completely, hence the question. ...
1
vote
2answers
304 views

what is knob heterochromatin?

I am reading a paper which discusses Maize Genome Structure. Descriptions of the structure is given in the papers introduction. I know about heterochromatin "heterochromatin stains intensely, ...
4
votes
1answer
121 views

Identification of this Salamander

This salamander was found in a small forest pond somewhat near the Oregon coast. In the area are many rough skinned newts and a small number of another type of salamander that I still can't find the ...
7
votes
3answers
128 views

Are there echolocating insects?

Echolocation is the ability to obtain spatial information of the surroundings from echos generated by the animal. There are bats and other vertebrates that naturally use it. I was wondering if this ...
2
votes
2answers
204 views

Basic text/notes on DNA structure (for non-biologists)

I am a mathematics grad student researching knot theory, and I've recently discovered that there is a connection between knot theory and DNA structure (if I understand correctly, when DNA strands ...
6
votes
3answers
229 views

If I built a concrete pool, would it ever contain fish?

Imagine that I built a concrete-walled pool the size of a football field and filled it with fresh water - obtained from another lake but free of bacteria, plantlife, eggs, etc. Would it ever, over ...
0
votes
1answer
56 views

Male behaviour during breeding season

The mountain blue bird build nests to attract females and exhibit aggression towards other males during breeding season. Which of the following is likely to give the birds maximal evolutionary ...
3
votes
1answer
75 views

Fear in elephants

It has been noted that elephants trained for war, as was done occasionally in earlier times, have still shown a tendency to panic in battle much more often when compared to a war horse trained for the ...
1
vote
1answer
59 views

Why are Lymphatic trunks part of the Cardiovascular system?

According to Wikipedia the Terminologia Anatomica (international anatomy standard) the lymphatic trunks are part of the cardiovascular system instead of the lymphoid system. Why did they make that ...
1
vote
1answer
143 views

Need of Creatinine Phosphate

In muscle cells most of the ATP's phosphate is with creatinine phosphate. So why is the displacement of the phosphate group done ? Is it because creatinine phosphate would give it's phosphate more ...
1
vote
1answer
195 views

Change of phase from juvenile to adult in plants

I tried googling this but couldn't get much information on this. Most of the articles were about induction of flowering. I am more interested in knowing what factors influence the conversion of ...
2
votes
2answers
484 views

What is an 'ex vivo' experiment?

Simple terminology question: Is there a hard boundary between in vitro and ex vivo? Is there a hard boundary between in vivo and ex vivo? Suppose a sensory neuron is electrically recorded in the ...
4
votes
3answers
124 views

What makes a metal safe to use for an artificial joint?

What determines if a metal is suitable for transplantation such as in the hip? What I am most interested in however is why might some metals be toxic to animals once in the body?
0
votes
5answers
283 views

Is evolution true as Darwin said? [closed]

I was telling the theory of evolution to my friends. But they asked me for the proof. They said, we are not seeing any such transition species at present. Neither we have such evidence for evolution. ...
2
votes
1answer
41 views

What are the methods for infering genetic interactions?

Is there a classification of methods for inferring genetic interactions? I mean some work published, utilizes genetical genomics data. Is this possible with expression data alone? And how about ...
3
votes
1answer
50 views

Effect of arteriole dilation on vein

If an arteriole leading to a capillary bed is dilated will the pressure in the vein coming out from the bed decrease ? Will the velocity of blood in the vein change ?
0
votes
1answer
189 views

Organelles present in sieve tubes

I know that sieve tubes do not have ribosomes, nuclei and cytoskeletal elements. What other organelles does it not have? Does it have a cytoplasm?
2
votes
1answer
99 views

Rate of Evolution of population of long lived individuals

Is it necessary that rate of evolution of longer lived trees will be lesser than that of annuals ? I understand that new individuals will come up faster in annuals and it may adapt to varying ...
3
votes
0answers
30 views

Division of Polar Body

The first polar body formed after meiosis-I is completed in oocyte, may or may not divide. Why is the statement that "it may or may not divide"? Is it random ?
0
votes
1answer
167 views

Need of X or Y chromosome protein after meiosis

After meiosis each spermatid get either the X chromosome or the Y chromosome. I know that the 4 spermatids formed from 1 spermatogonia are connected by cytoplasm and so the proteins made by X or Y ...
2
votes
1answer
189 views

Do people of the same height walk at the same speed?

I'm working on a project that concerns movement and the human body. Before I begin to experiment, I need an answer to a question I'm sure has an answer, but doesn't Google well. What I need to know ...
5
votes
1answer
62 views

How do rodenticides with delayed effect work?

Most modern rodenticides are claimed to cause death no earlier than several days after ingestion. That's quite strange - once a chemical was ingested it will be absorbed in the digestive system and ...
8
votes
1answer
188 views

Is it a limitation of the eyes, or the brain, that we can't see a moving bullet?

Are the photoreceptors in our eyes not fast enough to register the fast moving bullet, or is the brain not powerful enough to make sense of something happening that fast?
4
votes
3answers
3k views

What's a non-allelic gene?

Non-allelic or non-alletic I stumbled across the term in my Human Genetics textbook. It didn't explain it there, and a quick google search only showed scientific papers that refer to 'recombinations ...
7
votes
1answer
480 views

RNA seq and using of Poly(A) or non-Poly(A) based amplification of RNA

I'm studying "Deep sequencing the circadian and diurnal transcriptome of Drosophila brain" Hughes et al., 2012. I've got some problems with the materials and methods. Before RNAseq, the authors ...
0
votes
1answer
46 views

What happens to potassium after an action potential?

If I understand right, after repolarization, much of the potassium is outside the membrane and much of the sodium / calcium is inside. How does it get back to the original concentrations (i.e. ...

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