0
votes
0answers
20 views

about diffusion equation [closed]

consider the heat equation $u_t=a(t)u_{xx}+f(x,t)$, $0<x<L$, $0<t<T$ subject to the initial condition $u(x,0)=g(x)$ and boundary conditions $u(1,t)=0,$ $u_x(0,t)+hu(0,t)=0$ where ...
0
votes
1answer
17 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
21 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 ...
0
votes
1answer
21 views

Can connections between neurons be weakened?

Connections between neurons are said (by Wikipedia) to be strengthened as part of learning - can they also be weakened (below the original level)? I understand the concept of the connections ...
12
votes
3answers
31k 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
10 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
43 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
59 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
60 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
12 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
226 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 ...
0
votes
0answers
13 views

Cellulase Assay [closed]

I'm doing an investigation on the effect of temperature on cellulase. I have done a cellulase assay twice and it has been a failure both times. Can anyone recommend an assay that will only take ...
5
votes
1answer
75 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
109 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
35 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
22 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
30 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
33 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
42 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
29 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
130 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
20 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
52 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
16 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 ...
4
votes
1answer
29 views

What are “anchor regions” in the human genome?

I've been reading this paper entitled "A high-resolution map of the three-dimensional chromatin interactome in human cells", about interactome in 3D chromatin. We next applied the above algorithm ...
0
votes
0answers
26 views

Interpreting Graph

I am studying evolutionary biology, and been presented with this graph: I am having some difficulties understand its meaning. For a start, why is time measured as a fraction of the population size? ...
0
votes
0answers
25 views

Do animals have social status as humans in our society?

As our society and it's functioning is closely related to the ones of animals, one question arises: Do animals in nature have social status as humans? People often display it publicly, by buying nice ...
2
votes
1answer
22 views

Effect of extremely hard water on marine life?

When researching water quality standards, I found that a minimum and maximum was set for water hardness. Several sources also state that water can in fact be too hard. The question is how does hard ...
1
vote
0answers
19 views

How many traits can a multivariate breeders equation handle?

The multivariate breeders equation (MBE) by Lande predicts the change in a trait $\Delta \bar z$ (response) as $\Delta \bar z = G \beta$ where $G$ is a genetic variance-covariance matrix and ...
2
votes
0answers
20 views

What do we know about the cellular structure, processes, environment, and immediate ancestors of the last universal common ancestor (LUCA)?

I am up for all scientifically sound speculations, and sources are highly welcome. I've looked into this quite a bit myself via scholar.google, the wiki article, and /r/askscience. I'm really looking ...
1
vote
0answers
29 views

What is this animal? A worm which make round hole in on the ground [closed]

From South East Asia. There are some (perfect) round small hole in my garden (d=0,3 cm). They are the home of a small, strange worm, which I can't know the name. When I put an bamboo young leaf (used ...
0
votes
1answer
29 views

Help me understand how the thyroid secretes

Please have a look at this close up light microscopic image of a thyroid gland: So I'm guessing the cubic epithelial cells surrounding this big red pulp are the secreting cells...? If so, is the ...
0
votes
1answer
36 views

Organisms using thermal energy as their sole energy source

After seeing this question I remembered that in secondary school we watched a documentary stating something along the lines of "all organisms derive their energy directly or indirectly from the sun. ...
4
votes
0answers
38 views

What are the effects of long-term liquid breathing?

I just saw a recent Physics question that mentioned liquid breathing (which I had never heard of before) and I started to wonder about its long-term effects. Let's imagine a person underwent liquid ...
2
votes
1answer
46 views

Active & passive transport question

If an element, ion or molecule is found in a cell is it possible to tell which method of transport was used? for example if a hydrogen or sodium ion was found in the cell could you tell if it got ...
0
votes
1answer
52 views

Why would the stroma have a higher pH during photosynthesis?

Here is a question form my test. If you could measure the pH of the interior of thylakoids and the surrounding stroma during active photosynthesis what would be the relative pH of each? The ...
1
vote
1answer
65 views

Evolution, What would the first plants have been like?

I am curious what the first plants are thought to have been like, what they may have evolved from, and how much earlier (or later) than animals they are thought to have moved to land, if they even ...
2
votes
0answers
83 views

Questions about insects eating flour and living in the cracks of a wooden cutting boards

I have a large wooden cutting board which is used in kitchen mainly for preparing egg pasta. The wood type is Populus (poplar or aspen or cottonwood). The main ingredients used with the cutting board ...
3
votes
1answer
55 views

Hair loss in a submarine?

Biologically, how critical is hair loss on a submarine? What is the prolonged exposure of a navy officer going to do to that person, say over a year or even more?

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