4
votes
3answers
104 views

How to create a collection of anonymous sequences for teaching and testing? [closed]

I am looking for a large collection (>1000) of sequence files (eg. FASTA) from any real organism or a tool to create such a collection. The sequence files would be used for teaching and for testing ...
3
votes
1answer
274 views

Does chicken embryo form the disc called “discoblast” in the cleavage and blastulation of chicken?

This thread is related to my previous thread which is still unsolved mainly. I need to be able to compare chick and human cleavage and blastulation of zygote. My friend says that Chicken have ...
3
votes
1answer
998 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 ...
8
votes
3answers
327 views

Long-term-potentiation and memory. Where do we stand?

I was reading the answers to the question: How and where, in the human brain, are memories stored? and, as expected, LTP and LTD came out. Every time I read about LTP/LTD there is always something ...
8
votes
1answer
253 views

Is it possible to add a new sequence to a blast database without recreating it from scratch?

I have a new sequence and I want to add it to a pre-constructed BLAST database containing other sequences. The makeblastdb help does not give any hint on this regard.
11
votes
4answers
264 views

What can you tell about a person, having only their whole genome as information?

Well, the question is in the title, no explanation need.
7
votes
1answer
4k views

Why does RNA adopt an A-form helix?

RNA is known to form an A-form helix, while DNA generally forms a B-form helix under physiological conditions. From left to right: A-form DNA, B-form DNA, Z-form DNA. Image created by Richard ...
2
votes
2answers
789 views

What are the most important differences between HSP70 and HSP90?

Question originally asked on Quora. These proteins have many functional similarities, so why do cells need both to handle unfolded proteins?
7
votes
1answer
128 views

PDB Mining: Why Do I Find Atoms Less than 1 Angstrom Apart?

I am attempting to find potential Hydrogen bonds between Hydrogen donors and aromatic ring acceptors. I do this by predicting the location of Hydrogens on residues and then calculating how far these ...
6
votes
1answer
551 views

What forms the human amniotic sac?

I am trying to understand the formation of embryonic disc for human and chick so the following question is related to here about formation of embryonic disc. I had thought that the amniotic sac forms ...
7
votes
3answers
598 views

Determining potential protease sites within a recombinant protein

My expressed proteins are frequently truncated and I'm trying to figure out which bands are which. The first thing to come to mind is using PeptideCutter from ExPASy but there is just a data deluge of ...
7
votes
1answer
160 views

Taxonomy for plasmids

I liked the question about F' and R plasmids. What is a good resource that describes what is known about the functions and diversity of plasmids in the wild? Prokaryotes or eukaryotes? Wikipedia ...
6
votes
2answers
858 views

Density of neurons/cells in the mouse brain

Could someone point out some relevant papers or resources (an online DB maybe?) describing the density of neurons (or, more in general, of cells) in different areas of the mouse brain?
8
votes
1answer
218 views

What are the biochemical processes occurring when food spoils?

Let's assume for a minute that microbes themselves and their direct toxic products (i.e. endotoxins) aren't toxic to humans. Let's also discount any innate immune responses the body mounts against the ...
12
votes
3answers
727 views

Why do restriction enzymes tend to have an even number of bases in their recognition site?

When reading my textbook I noticed that in all examples but one from eight the recognition site was an even number of bases. I wondered if this was just a co-incidence, so I took the data from this ...
16
votes
1answer
690 views

ATP cost for gene expression

How would you estimate the number of ATPs required to transcribe, export and translate a single eukariotic protein?
5
votes
3answers
145 views

Can genetically modified genes jump to bacteria in the eater's intestine?

The Guardian ran an article a while back talking about GM gene's jumping to bacteria in an eater's intestine. Has other research confirmed this phenomenon?
12
votes
2answers
473 views

Which is more important for protein expression mRNA structure or codon optimization?

The field seems extremely divided on the debate. On one hand, artificial experiments have suggested that synonymous mutations don't correlate with gene expression but rather, the mRNA 5' structure is ...
5
votes
3answers
1k views

Fetal development, gastrulation and embryonic disc

I am completely confused by the images circulating on the internet of human gastrulation. First, lets see how it happens in deuterostomes. This image depicts the process: (image is from Wikipedia) ...
4
votes
1answer
257 views

What did pangolin scales evolve from?

Were they developed anew or a heritage from fish?
10
votes
2answers
450 views

Antibacterial hand soaps (and related products); what are they good for?

From Wikipedia: Household use of antibacterials in soaps and other products, although not clearly contributing to resistance, is also discouraged (as not being effective at infection control). ...
6
votes
2answers
102 views

Is there a term for tool use in animals?

Is there a technical/scientific term that scientists use to refer to tool making abilities found in certain types of animals? Reference ...
17
votes
3answers
237 views

How crowded is the bacterial cell?

I was wondering what is the protein concentration in an E. coli cell. When studying enzyme kinetics and activity in vitro, I would argue that the substrate and enzyme concentrations resemble those in ...
6
votes
2answers
2k views

Can any other animal choke on food?

I read somewhere (I think it was Bill Bryson's book on the origins of the English language) that of all animals, we are the only ones that can choke on food (having something to do with how our larynx ...
3
votes
0answers
34 views

Can a cell culture insert plate be used with a vacuum manifold?

There exists 96 well plate setups for use with vacuum manifolds. Is it possible to use 6/12/24 plate inserts with the same setup?
7
votes
2answers
27 views

What data / tools exist for mapping of disease trends?

I was just looking at the Google Flu Trends map. Google Insight could be used to gain similar information for other trends in disease keyword searches. I started wondering how valid are keyword ...
8
votes
2answers
161 views

Are prions an important driver in evolution?

I understand that prions have been implicated in the passing on of epigentic information[1]. Are prions thought to play a significant role in the evolution of organisms? Alberti S, Halfmann R, King ...
13
votes
1answer
251 views

Do the majority of fish lack scales on their heads?

Based on pictures, it seems to me that a vast majority of fish species that have scales do NOT have scales on their heads. Is that fact true? To make this properly answerable: lets' define a ...
12
votes
4answers
411 views

Questions to ask to a panel of people that will be sequenced

Some genes have been shown to be associated with left-handedness. Working with some clinicians, I've recommend them to ask their patients (whose genome will be sequenced) if they are "right or ...
5
votes
1answer
768 views

Do eye muscles relax when you close your eyes?

I wonder whether the eyes muscle relax when you close them. Common knowledge told us the eyes muscle get tense when you stare at nearby object. If you close your eyes, you eye lids have 0 distance ...
5
votes
2answers
4k views

Why is it that cats can jump so high for their size, compared with humans?

My cat is about 1' high at the shoulder, and I am a little over 6', but my cat can easily jump onto something as high as I am. That is 6x it's height. If a cat can do this, then Why can't I jump up ...
9
votes
2answers
2k views

If I graft two trees together while young, will they grow as one plant?

If I were to graft two apple saplings together, by bending the tops toward each other and lashing them together, will the plants grow as one and benefit from one another, or will they be fighting each ...
3
votes
1answer
2k views

Why did the sensitive plant (Mimosa pudica) evolve its leaf-closing mechanism?

Why did the sensitive plant, Mimosa pudica, evolve its leaf closing mechanism? Does it heip in a heavy storm? Does it scare off whatever animals might think it a good meal?
19
votes
1answer
270 views

Evolutionary origin and exogenous cues of ~28 day infradian rhythm?

The most obvious example of an approximately monthly biological cycle is the human menstrual cycle. My questions are the following: Is it known when and where this cycle or one like it arose? What ...
10
votes
2answers
180 views

Can DNA produce ribozyme-like structures?

RNA is known to act as an enzyme via its ability to fold itself in specific ways. Is DNA capable of such structures? Or is it some biochemical reason stopping the folding? Have they been observed in ...
7
votes
1answer
229 views

How do plants 'tell time' for circadian rhythms based on a ~24 cycle?

I've read that many plants have some sort of circadian rhythm where they perform a certain action on a cycle of about 24 hours, like the mimosa plant opening and closing its leaves. Obviously this is ...
7
votes
1answer
836 views

Does extracted DNA degrade after a certain time period?

For direct use as template in PCR runs. Chelex 100 5-10% w/v extraction. Without listing the whole protocol, in the end the supernate is decanted off and then stored at 4°C. I was under the impression ...
10
votes
3answers
585 views

What is the most heat-tolerant organism?

What is the most heat-tolerant (or heat loving - hyperthermophile) organism so far identified? What adaptations does this organism have in order to endure such high temperatures?
4
votes
2answers
2k views

How would a plant sprout and grow in a zero gravity environment?

Have any experiments been carried out involving sprouting and growing plants in a zero gravity environment? If so, what was the outcome? How did the plants sprout out of the soil without gravity? Did ...
3
votes
2answers
116 views

Would a plant need light if the chemicals gained by photosynthesis were given through the roots?

If you took the chemicals a plant gains through photosynthesis and put it through the plants' roots or by tubes, would the plant need light? If not, how would it respond to the treatment?
9
votes
1answer
405 views

Why can you graft two unrelated cacti successfully, but you cannot do this on garden trees?

Any cactus can be grafted onto any other cactus, and even the most unlike of them grow together. My latest graft was a Schlumbergera truncata scion on an Opuntia microdasys rootstock. This kind of ...
6
votes
1answer
626 views

How does water move throughout plants?

I haven't yet found a decent explanation for how water moves throughout plants. It does seem to travel more efficiently upward than out or down. Why is that? How does it travel through the plant?
11
votes
4answers
5k views

Do cows produce milk excessively?

Do cows produce more milk than it is required for their calves? It seems like cows are able to provide milk all the time (all year around). Is it so? Or do they, like other mammals, produce milk only ...
25
votes
2answers
5k views

What is the advantage of circular DNA in bacteria?

From what I understand, bacteria have circular DNA. What advantages does it have over linear strands like for eukaryotes? Do there exist bacteria with more than one ring of DNA?
9
votes
1answer
284 views

How is the number of mitochondria in a cell regulated?

How does the cell regulate the number of mitochondria in a cell? What happens when there are too many or too few?
3
votes
1answer
424 views

How often can you reuse coomassie stain?

I usually heat to boil in the microwave, and stain for 12 minutes. How often can I reuse this buffer?
12
votes
1answer
568 views

Sequencing the genomes of polyploid organisms

I've done some transcriptomics work in the past with a polyploid organism, and this presented some unique challenges in the data processing and analysis. Since then, I have been brainstorming about ...
10
votes
1answer
257 views

Is the minicolumn the unit of the neocortex?

There are many arguments for what the unit of the neocortex is. "Columns" seem to be the standard, but what exactly those are is extremely contradictory between individuals, cortical regions, and ...
13
votes
1answer
471 views

How do porcupines keep from pricking each other while mating?

How do porcupines keep from pricking each other while mating? It seems like they would constantly be scratching each other.
10
votes
2answers
560 views

Do insects with compound eyes have depth perception?

Do insects with compound eyes have depth perception? They fly as if they do, but their eyes are so close together it seems like the image would be 2 dimensional.

15 30 50 per page