All Questions

5
votes
1answer
37 views

What (if anything) about tuberculosis makes producing a highly effective vaccine difficult?

What about tuberculosis makes it difficult to produce a safe vaccine that is effective at producing an immunogenic response in >99% of individuals against all strains of the bacteria? I am aware of ...
2
votes
1answer
34 views

Why can't we smell our own bad breath? [closed]

Why can't we smell our own bad breath. Is there any way we can do that?
-1
votes
0answers
16 views

Dog with failing vision - how can we help [migrated]

Our border collie is getting old. Her eyes are beginning to fail and there are clear signs of cataracts. She seems to sometimes feel stressed when she encounters stripes of contrasting colours. ...
3
votes
1answer
29 views

How can ingesting a prion “infect” someone?

That's something that's been bugging me for a while... Our gastrointestinal tract produces proteases that degrade proteins. Prions are proteins. Shouldn't they be broken by proteases? Also, how can ...
5
votes
3answers
248 views

Is there an 'anti-virus'?

A virus spreads around and usually attaches itself to the host, multiplies & causes diseases. But is there something like an anti-virus? A single celled entity that does the opposite: spreads ...
1
vote
1answer
273 views

Do plants absorb toxins from the soil?

Consider a plant like Aloe Vera that grows up in a toxic environment where the concentration of pesticides, and materials like lead, mercury, cadmium, arsenic etc is very high(e.g. Marshland dumping ...
2
votes
1answer
21 views

How isolated are different areas of the brain?

I'm interested in understanding how isolated different parts of the brain are from each-other. I'm trying to understand the way that different sections of the brain work together. More specifically, ...
1
vote
1answer
56 views

Why is it called “Ebola virus disease”, not just “Ebola” or “Ebola disease”?

Why do scientists (pretty consistently) call it Ebola virus disease, rather than just Ebola, or Ebola disease? Many other diseases are caused by viruses, but they don't seem to have this detail of ...
5
votes
1answer
72 views

How does the brain avoid feedback loops?

The article Ants Swarm Like Brains Think really helped me to understand the way that neurons which are pretty dumb on their own (like ants) can work together to create a pretty genius system (a brain ...
5
votes
3answers
57 views

Do you know of any disease where HLA / MHC association discovery has led to better treatment or management?

If we discover an association between a disease and a particular HLA type (MHC class I or class II molecule) then it may provide us with some insight into the disease in a very basic way. However, ...
0
votes
0answers
11 views

Is there a known glucosepane cross-link breaker?

I read the following on wikipedia: There is, however, no agent known that can break down the most common AGE, glucosepane, which appears 10 to 1,000 times more common in human tissue than any ...
22
votes
4answers
4k views

Why don't mammals have more than 4 limbs?

Arthropods have 6 or more limbs and arthropods with 6 limbs appear to move faster than arthropods with 8 limbs so I wonder whether this might have something to do with fast and efficient locomotion. ...
1
vote
1answer
21 views

Gene duplication and subfunctionalization

I’ve been intrigued by gene duplication and want to learn more about it. I’ve read the following from here: several studies suggest that the proportion of duplicated genes retained in ...
1
vote
1answer
8 views

Can inverted microscope also be phase contrast microscope?

I've read somewhere that inverted microscope also allows phase contrast microscopy. Is that true? Do all inverted microscope have this ability? Do they have any other functions? Many thanks in ...
2
votes
1answer
208 views

which exact mechanism triggers the first cell differentiation after n divisions?

I would like to understand which mechanism triggers the first cell differentiation after n divisions. I read previous articles on SE and Wikipedia articles on cellular differentiation and ...
2
votes
1answer
404 views

What species is this large-ish spider?

Last night I came across this spider outside my house (costal Southern California). It was bigger than any I'd seen before, about 2.5 or maybe 3 inch legspan, maybe just under an inch for the body ...
7
votes
3answers
738 views

Why did abiogenesis only happen once?

If the "primordial soup" theory of abiogenesis is to be believed, self-reproducing organisms spontaneously arose on Earth at least 3.5 billion years ago, surprisingly soon after the Earth cooled down ...
4
votes
1answer
44 views

Why is the ebola virus so intense now?

So i'm looking into the ebola crisis and it seems the death toll is really getting crazy. I understand that it's a cytomegalovirus and that it basically overwhelms the immune system due to it's size ...
0
votes
1answer
18 views

Is the brain functionally symmetrical?

I understand that each half of the human brain handles different parts of our thinking. Left brain, right brain, that whole topic. But in pictures, the brain is always depicted as having symmetrical ...
2
votes
1answer
23 views

Why is coconut oil healthier when it has so much saturated fat?

I noticed that coconut oil has ~96% saturated fat, and I was under the assumption that saturated fats = bad for health. Why is it that coconut oil is healthier to alternatives with much less ...
12
votes
3answers
32k views

NADH vs. NADPH: Where is each one used and why that instead of the other?

I know NADH is used in cellular respiration and NADPH is used in photosynthesis. What difference does the phosphate group make that the same one isn't or can't be used for both? Is there a greater ...
1
vote
0answers
13 views

Can sealed epiphyseal growth plates theoretically be restored via epigenetic or genetic methods?

I know that epiphyseal growth plates seal up once people become young adults and that it is currently impossible to restore them to actively produce new bone growth but, is it theoretically possible ...
2
votes
1answer
45 views

How are arms different than legs?

Ok, this is a bit of a tangent question, but it came up yesterday and I didn't know the answer: How are arms and legs defined physiologically? For example, we say humans have two arms and two legs, ...
4
votes
1answer
62 views

How did people who were living far from the sea obtain iodine during the Middle Ages?

Knowing that today iodine comes either from fish products or (artificially) enriched table salt, how did people who lived far from the sea survive before (especially during the the Middle Ages)? Edit ...
0
votes
1answer
24 views

How do colds and flu not infinitely recur?

I'm in my third week of university, and a large number of people I know, including myself, still have "fresher's flu", which is probably just a cold and a cough. My lectures are constantly punctuated ...
0
votes
2answers
63 views

Is it possible for a child to grow taller than their tallest parent?

I have heard that off spring can't grow taller than either of their parents but I've also heard that sometimes some gene activation can skip generations. Is it possible for a child to grow taller than ...
3
votes
0answers
15 views

Gibson assembly - primer design with A and T rich regions

I have question about Gibson assembly. I have done it several times and it always worked okay for us, but now I want to assemble together a fragment which has sequence like this: ...
0
votes
1answer
24 views

What is frank dehydration?

On Wikipedia article about Urine specific gravity we can read: A specific gravity greater than 1.035 is consistent with frank dehydration. What is frank dehydration? How it is different than ...
2
votes
1answer
59 views

What is the scientific and common name of this bug?

Captured this under my stereo microscope. Much beautiful than appearing on my camera sensor. Can someone help me identify it and explore more? Also is it having a compound eye ?
17
votes
4answers
1k views

How do trees manage to grow equally in all directions?

I was walking down a road with these beautifully huge trees when this question occurred to me. Large trees with many thick branches have to grow equally in all directions, or they would tip over. Is ...
0
votes
0answers
20 views

Is Canine teeth enough evidence to prove that one is a Carnivore?

This question does not assume that we are meant to be carnivores in the first place; In fact I have no idea to which category we belong to anyway! There are several posts online indicating that ...
4
votes
2answers
229 views

Were there lifeforms before LUCA?

This question got me thinking about something. LUCA is the last universal common ancestor of all current living organisms, which is a very different definition from the first-ever living organism. Is ...
8
votes
2answers
449 views

Has anyone tried Gibson Assembly Optimizations?

Has anyone tried the chew back-anneal in vitro DNA assembly method (known as Gibson Assembly) for difficult sequences, like GC-rich sequences? How big constructs could you efficiently assemble? Did ...
5
votes
1answer
83 views

Effects of selection on effective population size

Background The effective population size ($N_e$) is a central concept of evolutionary biology and is influenced by several parameters. For example: sex ratio bias affects $N_e$ $\left(N_e = ...
4
votes
1answer
111 views

How to calculate the effective population size ($N_e$) with overlapping generations?

From this Source: If generations are overlapping, then the effective population size $N_e$ does not equal the population size $N$. I know mathematical formulations in order to find the effective ...
2
votes
1answer
37 views

What is the result of meiosis?

Is the result of meiosis ONLY the sex gametes (male and female) which later meet to form a somatic cell? Sometimes I feel as if my book is hinting towards meiosis is the process where sperm cells meet ...
3
votes
2answers
23 views

What would happen if there were no SOX9 in an XY human?

Would testes be produced? If SRY is functional, can it produce other proteins that can direct the production of testes, which may or may not be sterile?
0
votes
0answers
16 views

Best method to culture lung fibroblasts?

I am just looking for the best method to culture human lung fibroblast from a needle biopsy?
1
vote
2answers
31 views

True or False: Vaccines are designed to protect against invaders that are encountered rarely, not all the time

I read the following statement in this article: Vaccines are designed to protect against invaders that are encountered rarely - not all the time Is it true? If yes, why?
0
votes
1answer
22 views

Does adding antibiotic after 5-10 mins of innoculation affect the protein yield or growth?

I've asked a lab colleague the same question. She said, it would loosen the bacterial cells in the LB medium and plasmids would come out. Is that true? and why?
0
votes
1answer
34 views

Is the innate immune system capable of identifying all foreign antigens?

I've been studying immunology on my own lately and I would like to know if the macrophages and the other components of the innate immune system are capable of identifying all foreign antigens. As far ...
2
votes
0answers
44 views

When the mind is highly active, roughly how many neurons become excited in one second?

I'm curios to know how many times neurons send signals in one second when the brain is highly active (Highly active meaning during difficult problem solving, or any task that might bring the brain to ...
0
votes
0answers
30 views

Why are there no animals with a length greater than 30-40 meters or with a mass greater than 200 tonnes?

The biggest and heaviest aquatic animal is the blue whale: 30 meters long and a mass of 200 tonnes. The biggest and heaviest terrestrial animal was a Sauropod (plant-eating, long-necked dinosaur): 40 ...
44
votes
4answers
3k views

Why do plants have green leaves and not red?

I know plants are green due to chlorophyll. Surely it would be more beneficial for plants to be red than green as by being green they reflect green light and do not absorb it even though green light ...
4
votes
3answers
131 views

Why can't you just take a vitamin? Why you need a healthy diet on top of that?

From what I understand, your body needs certain amounts of vitamins and minerals to maintain health. Why can't we just take enough pills to obtain these vitamins and minerals?
0
votes
0answers
16 views

Recovering Coma patient with theoretical full knowledge of heart function

In coma, there is the medullary depression (stage of agony). Spontaneous respiration and circulation cease i.e. vasomotor center. There is no full circulatory and respiratory support. Assume you ...
0
votes
1answer
21 views

Do the light and dark reactions happen at the thylakoid?

My professor said that light reactions and dark reactions happen at the thylakoid. He did not choose the answer that "both reactions happen at chloroplast". Isn't the thylakoid a part of the ...
1
vote
1answer
26 views

What is meant by a muscle fiber being glycerinated?

I was popped this questions today, "what is a glycerinated muscle fiber, and what is required for its contraction," and had little idea. I'm assuming the question is "what's required for its ...
3
votes
2answers
55 views

Proteins with alpha helices alone and beta sheets alone?

I would like to see some examples of proteins with PDB ID so that I can download and see them in VMD software. I need some proteins with alpha helix only and proteins with beta sheets alone.
0
votes
1answer
17 views

Cell targets of Glybera

So we know that there is a first gene therapy drug in the market out there called Alipogene tiparvovec to address lipoprotein lipase deficiency (LPLD) at a genetic level. Does this genetic drug ...

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