-4
votes
1answer
15k views

What is the difference between the Ureter and Urethra? also between the Renal papilla and Renal pelvis? [closed]

Differentiate between the following: Ureter and Urethra Renal papilla and Renal pelvis It is not given in my book. Please help.
30
votes
5answers
2k views

Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?)

Reading this question, Why are there no wheeled animals?, I wondered why no organisms seem to make use of the tensile and other strengths of metal, as we do in metal tools and constructions. I am ...
0
votes
1answer
175 views

Why not produce protein based on condensation reaction?

I'm fairly new learning about protein. As I know protein can be synthesis by condensation reaction. And the current method to produce protein is purify them from an organism. So why not produce ...
4
votes
1answer
209 views

Cloning two fluorescent proteins with different promoters in the same plasmid?

I want to clone two fluorescent proteins both driven by different promoters in a plasmid to be used to transform B. subtilis at the amyE locus. For this I want to use plasmid pSG1729 (Lewis and ...
1
vote
1answer
175 views

Is Nerve Growth Factor (NGF) commercially available?

I'm curious if NGF, or Neurotrophins in general is available commercially. Can I order it online? If not, what are the medical/biological reasons. Does it breakdown quickly after synthesis/capture? Is ...
1
vote
1answer
119 views

What is the mechanism of labeling a DNA molecule with deuterated water?

I have seen a paper in which deuterated water was used to follow dividing cells. The assumption was that deuterated water will be incorporated into newly synthesized DNA molecules. Is there any direct ...
0
votes
3answers
82 views

Could sex alone drive complexity?

Imagine that complexity is measured by a positive number $f_n$. If one has no prior knowledge about the positive number $f_n$ then from Bayesian theory one can assign $\log f_n$ an "improper" uniform ...
7
votes
1answer
278 views

What is this insect I found in Russia?

I found this in Russia. It is approximately 2cm long.
5
votes
2answers
56 views

Is there are practical lower limit to gene length in E. coli?

Question is rather self-explanatory. Putting aside other post-transcriptional factors like rate of degradation of transcript, what is the smallest gene ever reported to have successfully been ...
4
votes
2answers
315 views

Ecomorphs as evolutionary definitions

There have been demonstrations of ecomorphs in different taxa, where each morphology type is associated to a single environment. I know that it happens because special morphological characters ...
1
vote
0answers
40 views

why water is a proof of a life? [duplicate]

I read that NASA looks for water on Mars or other planets as a sign of a life. I wonder why scientists look for water as proof of a life? isn't there any animal that drinks another liquid like ...
2
votes
3answers
117 views

Is it possible to make humans extinct artificially?

Verging on the realm of science fiction, my question is that is there any theoretically possible way, biologically/chemically, with which the entire human race can be killed without affecting the rest ...
2
votes
1answer
182 views

Is it really detrimental to humans as a species to reproduce with one's own first cousin?

Tired of hearing of these urban legends and popular opinions, I ask this question here to see if there really is scientific merit to this belief. My questions is, is it really "harmful" for a person ...
3
votes
1answer
55 views

How diverse are dogs in their traits other than appearance?

I've asked this question about dogs not so long ago, and the short answer was - dogs are the most diverse looking species of mammals because they got a small number of genes that have a big impact on ...
4
votes
1answer
2k views

How many honeybees are there, and how has the number changed across time?

How would you begin to estimate the world population of the European Honeybee (Apis mellifera)? Would recent colony collapse disorder show up as a blip? How about the spread of A. mellifera from ...
2
votes
2answers
212 views

What insect is in this photo?

Found in Russia, in the kitchen. It is about 1–2 cm length.
1
vote
0answers
296 views

Mass change in deamidation from Glutamine to Glutamate

To detect the deamidation from Glutamine to Glutamate in a protein, normal practise seems to be a mass spec, where it is claimed there is a change of 1 dalton. EG It is claimed that: Deamidation ...
2
votes
1answer
78 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?
2
votes
2answers
604 views

Do the four cells produced by meiosis each divide into four cells again?

In the beginning of meiosis, there is one cell. During meiosis, 1 cell divides into 4 cells. Does each of these 4 cells divide each into 4 more cells?
1
vote
1answer
159 views

Is chlorophyll living or non living?

Is chlorophyll living or non living, and after boiling the water out of a chlorophyll extract would it still live, as in would it still maintain its properties after re-adding liquid to the dried ...
2
votes
1answer
150 views

Any difference between inverted microscope objective vs normal microscope objective?

I'm planning to build an inverted microscope and I am not sure if I can use a plane achromatic objective of a normal microscope for the inverted microscope as well. Are there any specific needs for ...
3
votes
1answer
113 views

Competition with other individuals of the same species vs. adaptation pressure from predators

It is often said "You don't need to outrun the cheetah, just the other gazelles", thus emphasizing that greater part of the adaptation pressure comes from competing with other individuals of the same ...
3
votes
1answer
86 views

Enlargement of joints in osteoarthrosis

If osteoarthritis (osteoarthrosis) is a degenerative condition, where the cartilage in joints wears down, what causes the joints to become inflamed? I'm reading through a book called Understanding ...
3
votes
1answer
260 views

Has synthetic biology created new plants or animals as of 2013?

I've seen a Ted.com talk where the speaker suggests that modern science can create new micro organisms, like bacteria with a pre- defined new set of traits. But has anyone create a new species of ...
9
votes
1answer
120 views

Is there any evidence that humans have faced extinction before?

Have we as a species faced extinction in the past? Resulting in a 'population bottleneck'? If so, what genetic evidence is there of this occurring?
4
votes
1answer
53 views

Is there a link between autoimmune diseases and X-chromosome inactivation?

I was reading about the necessity of niche formations to adequate development of blood progenitors and this idea reminded me of the patchy inactivation of the X chromosome which followed that maybe, ...
5
votes
2answers
180 views

How does a new species survive without suffering inbreeding?

Just what the title states. The thought came from reading When has an organism evolved enough to be called a new species? I'm probably wrong but I understand new species happen sporadically rather ...
1
vote
1answer
1k views

In what animal species is the sex ratio skewed in favour of the fertile female?

Ants have something like a single fertile female to several males. The same applies to bees, and larger animals - elephants too. Is the sex ratio universally skewed in favour of the female? What ...
0
votes
2answers
231 views

How mosquitoes get their food and survive?

How mosquitoes find and get their food? For how much time they can survive without food?
5
votes
1answer
558 views

How can haired mammals synthesize vitamin D?

The human body can synthesize vitamin D in the skin from cholesterol, when sun exposure is adequate. But how can haired mammals do it? Do not they need it?
4
votes
2answers
375 views

Are there dangers to Teflon and aluminium cookware?

I've been reading some articles on the internet about dangers of Teflon and aluminium to the body. My family say I'm just exaggerating the situation, and maybe I am, though I'm not sure because not ...
2
votes
1answer
102 views

Earliest ancestor of humans who could integrate into modern society

Assuming the current model of human evolution to be correct, approximately when did the earliest ancestor of humans live, who was intelligent enough, that if raised from a young enough age, could ...
1
vote
1answer
98 views

Is iodised salt harmful to the lactofermentation process?

I was discussing sauerkraut recipes with someone on IRC a minute ago, and they warned me not to use iodised salt in the process. My first (and so far, the only successful) batch is one I made with ...
1
vote
3answers
62 views

Cell identification by Body Cells

How do the B-cells and T-cells recognize or distinguish a body cell from a foreign particle? I suspect something to do with this causes Auto Immune Disorders.
2
votes
2answers
154 views

Is this a valid principle of curing HIV?

I have a set of questions actually, it will be very helpful if you answer them in order. Where does the HIV virus hide (during incubation period)? Let answer be X cell. Is X cell in the bloodstream? ...
2
votes
2answers
669 views

Do primates other than humans have a consistent sleep schedule?

I'm doing some sleep research and would like to compare a human sleep pattern as recorded by a wrist-based actigraph with a "natural" sleep pattern, such as from apes. In an experiment like that, a ...
1
vote
1answer
784 views

Advantage of being deuterostome

We know that most of the so called "Advanced" organisms are deuterostomes (i.e., development of gut starts from anus). Is there any evolutionary advantage of that? If not, why and how did it evolve?
1
vote
2answers
77 views

Why can't we observe haplotypes directly?

I am completely a noob to biology and DNAs, but recently I am looking into EM-algorithm used in the case of re-constructing haplotypes from genotype data. I am just wondering what exactly in the ...
2
votes
1answer
2k views

What does phasing mean?

What does phasing mean in genetics/informatics? I've heard that a phased file is a file that has genes separated by chromosome, but can someone give a concrete definition of what phasing actually ...
1
vote
3answers
89 views

Would it be possible/plausible for a type of spider to fly by weaving web between it's legs to create bat-like wings?

I've been thinking about this lately. Would it be possible for a type of spider to gain the ability to fly freely by weaving its web between it's legs and creating wings much like those of a bat? Is ...
5
votes
1answer
84 views

Will eukaryotic RNA fold in the same way in prokaryotes?

As far as I know, there are no specific eukaryotic or prokaryotic factors that aid in RNA folding other than cellular environment (salt and ion concentrations, dissolved molecules, etc). Are there any ...
16
votes
3answers
1k views

Do animals exist with an uneven total number of digits?

I recently finished reading Contact by Carl Sagan. In the book they talk about a pattern in the transcendental number like pi or e, and comment that it is found in base 10 or however many fingers the ...
5
votes
1answer
139 views

Is (Brain Mass)/(Total Mass) still considered a valid indicator of intelligence?

I was reading this(1) and it led me back to ask a very basic question (I'm not a neuroscientist). All the way back to undergrad anthropology and neuroscience courses I remember being taught the ...
1
vote
2answers
387 views

What gases are needed for humans to breathe?

I will be beginning a science project about sustaining life on space stations. I already know that pure oxygen is harmful for humans but would $O_2$ + $CO_2$ be enough for humans to breathe in or do ...
3
votes
1answer
173 views

Any tool to align whole genome sequence data to another genome and give exon regions a higher mark?

I want to align WGS data from several mammals to one reference such as the human genome sequence. Since in most cases exons should be conserved and spliced in the same way and introns should vary, I ...
0
votes
2answers
97 views

Plant anatomy, what are these stem like filaments growing under the flower

The picture below shows what I am talking about. Each flower has one and I am just wondering what they are?
6
votes
1answer
73 views

Can two hammerhead ribozymes simultaneously cleave each other?

I am working on a project in which an XOR gate is being built by having two hammerhead ribozymes simultaneously cleave each other when both are expressed, but have these ribozymes cleave a target ...
2
votes
1answer
123 views

Is there an instinct-driven body language for birds?

Over the last year or so, I've been observing house sparrows, because they are so prevalent in the northeast US cities. I noticed that a lot of sparrows, even in different cities seem to have very ...
5
votes
3answers
300 views

Is recognizing one's own mirror reflection a valid test of animal intelligence/self awareness?

I've been looking at this Ted talk on interspecies internet, and it appears that they have selected a small number of species of animals (dolphin, elephant, and some ape(?)) and are intent on ...
1
vote
1answer
64 views

Isoprenoid Diphosphate Concentration in Yeast saccharomyces cerevisiae

Isoprenoid Diphosphate(IPP) is an important metabolites which is precursor in lot of secondary metabolites like Dolichol diphosphate, ubiquinone, prenylated proteins and carotenoid (not synthesized ...

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