12
votes
2answers
452 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
237 views

What did pangolin scales evolve from?

Were they developed anew or a heritage from fish?
10
votes
2answers
434 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
98 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
220 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
26 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
156 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
231 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
396 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
702 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
3k 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 ...
8
votes
2answers
1k 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
245 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
171 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
217 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
798 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
546 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
114 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
377 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
613 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
4k 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
4k 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?
8
votes
1answer
265 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
384 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
539 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
249 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
420 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.
9
votes
2answers
522 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.
5
votes
2answers
639 views

How to set up a slow cooling on an AB Veriti thermal cycler?

I want to incubate my sample at 50ºC and then slowly cool it down to 4ºC at a rate of 0.1ºC/s. I am using AB Veriti thermal cycler. Does anyone know how to set up the rate of cooling? It has to do ...
3
votes
1answer
46 views

How can you improve solubility of colloidally dispersed substances?

If you solve collidally dispersed substances then the particles can form large colloids. This may block narrow passages and diffusion into dense structures may become completely impossible. What can ...
9
votes
1answer
2k views

How many mice are on the Earth?

We are 7 billion human beings on the Earth. But how many mice are there? How would you estimate such a number?
4
votes
1answer
94 views

Is there a cheap and easy way to check for potentially unsafe UV exposure?

My lab has an older large Fotodyne tabletop UV transilluminator for visualizing gels. It has a UV blocking cover that hopefully reduces UV that passes through, but I've always been suspcious as to ...
6
votes
1answer
402 views

X chromosome “weight”?

According to Wikipedia, the X chromosome has approximately 153 million base pairs, while the Y chromosome has only 60 million base pairs. Thus, the difference is roughly 93 million base pairs. My ...
7
votes
1answer
406 views

When do most mammals mate?

Is one part of the day more prevalent then other when it comes to mammal animals mating? Is there an aggregating study that has been done to see if these living beings in nature mate mostly during day ...
2
votes
1answer
270 views

What is the structure and function of chromosomes during interphase?

Ok, it seems to be easy but I have probably ignored something by accident. Interphase is the phase where things are growing and the preparation for cell division happens. Its stages G1, S and G2. DNA ...
6
votes
2answers
621 views

What is the main general difference between Mitosis and Meiosis?

I found such a clause: The general principle is that mitosis creates somatic cells and meiosis creates germ cells. However, I cannot agree. Each gametogonium needs to go through mitosis before ...
18
votes
3answers
6k views

What causes fingerprints to form and why is the pattern formed unique?

I've found research that suggests that the reason we develop fingerprints is because they aid us with feeling surfaces (Scheibert, et al. 2008) and not to increase friction and help with the gripping ...
14
votes
4answers
1k views

Can two humans with 44 chromosomes produce viable offspring?

It is known that there are very few individuals having 44 chromosomes, not the usual 46 chromosomes. One example is a male in China: the first article, the second article. The other is a female in ...
12
votes
2answers
341 views

Is there any reason for the variation in mitochondrial DNA size?

As my textbook An Introduction to Genetic Analysis points out, yeast mitochondrial DNA has approximately 78 kb of genetic data, while the human mitochondrial DNA contains 17 kb. Is there any evolution ...
13
votes
1answer
2k views

How does a plant grow before photosynthesis is possible?

During photosynthesis, a plant translates CO2, water and light into O2. I assume the carbon C is further used for the growing process. I wonder how the plant grows before the time where photosynthesis ...
4
votes
2answers
520 views

What's the advantage of autocrine signalling?

In the antibody-mediated immune response, when the helper T cell gets activated by the costimulus (IL-2 and TNF-α secreted by the APC) which in turn produces IL-2, IL-2 acts in an autocrine manner. ...
18
votes
3answers
14k views

Why do mammalian red blood cells lack a nucleus?

How did the red blood cell in humans get to lose its nucleus (and other organelles)? Does the bone marrow just not put the nucleus in, or is it stripped out at some stage in the construction of the ...
8
votes
1answer
187 views

Which organism has the sharpest vision?

Which organism has the sharpest vision in terms of distance and spectrum. Please propose any other useful measure.
7
votes
2answers
4k views

Mitosis in human body

I've heard that stomach lining has the fastest reproducing cells and the brain has the slowest. Where in the human body does mitosis occur and at what rates do these cell reproduce? Is there a chart ...
3
votes
1answer
257 views

Where does meiosis II of oogenesis end exactly in tuba uterina - uterus?

I know that metaphase II ends at ampulla tuba uterina, but I am not completely sure where the telophase II ends. Is it in the triangular section of cervix uterii? I just have an intuition that the ...

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