4
votes
1answer
55 views

Does the formation of water inside the mitochondrial matrix help contribute to the proton gradient during the electron transport chain?

Does the synthesis of water in the final step of the electron transport chain significantly increase the electrochemical gradient across the matrix? I understand that pumping protons out of the matrix ...
0
votes
2answers
192 views

Do chromosomes uncoil in interphase II?

During interphase II, there is no S phase in which DNA replicates. However, in this stage, do the chromosomes remain wound? Or have they unwound into chromatin form, and recondense during prophase II?
3
votes
1answer
29 views

Is this modification of Livak's 2-delta delta CT method valid?

I have done a modification to include qPCR efficiency in the calculations: In a given gene I calculate the fold changes relative to an arbitrary sample. That sample will be one and the rest will ...
-2
votes
1answer
44 views

Would someone lose some of their traits if they stop using them for some time? [closed]

A co-worker of mine told me, that there are some mutations in the genome during the life of a human body. So, the body changes genes to fit better into the surrounding environment. My thought is now, ...
2
votes
1answer
35 views

What's the highest glucose concentration (in mM) anywhere in the human body (tissue, capillaries, tumor microenvironment, etc.)?

Glucose blood levels are around 5mM, or 10mM after meals. In capillaries these levels can rise by about 40 %. I haven't found measurements of glucose concentration in tissues, or in extracellular ...
3
votes
1answer
51 views

Perplexing by the way of estimating the shared or different genes between humans and chimps

We share 98.5% genes with chimps (it means we have 98.5% same DNA sequeces ),so there is about one percent difference .It means we can approximately differ from them by one base pair every hundred ...
3
votes
3answers
68 views

Doubt in a multiple choice question involving cell organelles

Find the odd one out and state the category of the rest. Chloroplast Mitochondria Nucleus Grana Now my answers are : 1st possibility : grana Category : presence of DNA in ...
0
votes
1answer
100 views

Humans genetic/phylogenetic “next relative” in central Europe? [closed]

What species in central Europe in the phylogenetic tree shows the closest difference in time to the most recent common ancestor with Homo sapiens?
3
votes
2answers
76 views

Why does the gc content deviate from 50% in prokaryotes

I have read quite some articles but I can't figure out the main reason for gc content deviation in prokaryotes. In eukaryotes I can understand it, because the genome isn't composed at random, like ...
4
votes
1answer
71 views

Why can't we find a broad spectrum antiviral drug to viruses like antibiotics to bacteria?

Antibiotics have a very broad spectrum because they attack the metabolism pathways many bacteria share. For example, penicillin inhibits peptidoglycan synthesis, which is vital for formation of cell ...
12
votes
1answer
101 views

What made this black cluster on a leaf?

I found this black slug-shaped thing on a leaf by my pond in western Sweden. It's about 15 mm long, positioned on a vertical leaf (I bent it to take the picture). And I don't even know where to ...
1
vote
1answer
18 views

Binding kinetics of 6xHis-Tag

For the planning of an experiment I would like to know the binding kinetics (kon and koff) of a 6x-His-tag to a Ni-NTA surface. I know they should differ due to surface quality and position of the ...
5
votes
1answer
36 views

How allele is related to trait that is more complex than two cases (ex. height)?

Recently I started to learn about evolution and genetics. Simple stuff at the beginning - some videos, some reading. So far, everything seems to be pretty simple and straightforward. I easily grasp ...
1
vote
0answers
16 views

Are there any individual animals that can thrive in a wide range of core temperatures? [closed]

Surely, some cold blooded animals are in a position where they can't escape the changing temperatures the environment throws at them, so natural selection would have enabled them to thrive in a wide ...
9
votes
1answer
15k views

What is the standard deviation of adult human heights for males and females?

The wikipedia article on human height reports mean height for many different countries by sex but it does not report standard deviations. What is the standard deviation of adult human heights within ...
6
votes
4answers
406 views

Compressing structural information in PDB files

There seems to be a lot of redundancy in PDB files. These files can of course be compressed with general-purpose compression programs like gzip, but I can't help but imagine that these tools are ...
4
votes
1answer
136 views

What were the camels' humps good for back in the polar areas?

I've heard that camels lived in the North America formerly and just in the last few thousands years they've migrated to the hot deserts. Thus they allegedly utilized the adaptations against the cold ...
44
votes
5answers
5k views

Why do some bad traits evolve, and good ones don't?

If a trait would be advantageous to an organism then why hasn't it evolved yet? Conversely, if a trait is not advantageous or mildly disadvantageous, why does it exist? In other words why does ...
1
vote
0answers
10 views

Has research indicated how much koinophillia preferences are learned vs insinctual

I'm curious about rather the definition of 'normal', as it affects koinophillia & mate choice, is something instinctual or learned. To clarify I'm not asking if koinophillia itself is ...
2
votes
3answers
77 views

How valid is the theory of human's chimp-pig origin? [closed]

Edit: I have also asked the question on skeptics.stackexchange.com and it has been answered there. Here is the link. There is a person called Dr. Eugene McCarthy who has a theory that the origin of ...
8
votes
2answers
77 views

Is there a genomic code for nucleosome positioning?

What does a genomic code for nucleosome positioning in eukaryotes actually mean? By the code is it right to think that specific DNA sequences favour nucleosomes and others don't? I see that there for ...
-1
votes
0answers
32 views

If drinking nothing but distilled water kills you what happens when you're injected with it?

I've read that drinking distilled water and eating nothing can kill you, and I was wondering what would happen if someone injected it into your bloodstream?
2
votes
1answer
80 views

Why don't membrane proteins move?

I understand that based on their tertiary structure, intrinsic proteins have hydrophobic non-polar R-groups on their surface and that they 'interact with the hydrophobic core of the cell membrane to ...
0
votes
0answers
18 views

Can we make an artificial chromosome?

I know things like BAC and YAC exist. I am thinking of a chromosome the size of those we find in mammals. Say 60 million nucleotides. How big can we make a chromosome with modern technologies without ...
1
vote
2answers
110 views

How do I tell if the mosquitos in my New York City apartment can carry Zika?

The species that carries Zika, A. aegypti, is unlikely to be found in New York. However, the related species A. albopictus is prevalent and quite concerning. So this question is focusing on A. ...
3
votes
0answers
24 views

Why the name hypopharynx?

Why the tongue (like structure) in cockroach (or other insects) is called hypopharynx? In humans I know it's the lower part of pharynx, not a structure. Isn't this anatomical name misleading? Are ...
3
votes
1answer
59 views

Can a color-blind person see color with filter glasses? [closed]

Why does color vision improve in color-blind persons using these filter glasses from Enchroma? Will a color blind person be able to see the same colors on a television? I'm asking, because the colors ...
1
vote
0answers
20 views

What is meant by clinical progression? [closed]

What do the terms 'clinical progression' and 'disease progression' mean? Are they different from each other?
3
votes
0answers
31 views

Why does crippling pain exist? [closed]

Some kinds of trauma can cause pain so severe that it makes you unable to move or do anything at all. It may put you out of action and unable to help yourself because of how excruciating it is. ...
11
votes
0answers
144 views

Selection for less efficient egg transfer in Human Botfly life cycle

I have heard that the Human Botfly transfers its eggs through other invertebrates [1], and it strikes my curiosity that if an insect could simply land on its host directly to deposit its eggs, then ...
0
votes
0answers
12 views

How does entanglement explain myoglobin's preference for $O_2$? [migrated]

I was reading an article about the myoglobin's unusual preference for $O_2$ than CO, in which I found: It turns out that some electrons in the myoglobin involved in binding CO and O2 exhibit a ...
5
votes
2answers
317 views

What is the biological principle of this “holotropic breathwork” technique?

Holotropic breathwork is a non-drug technique developed by Stanislav Grof used in psychotherapy. The therapy as a whole is usually called holotropic breathwork (at least by Grof himself) and will most ...
2
votes
1answer
87 views

Techniques to show a protein heterodimer-DNA interaction

It is known that c-Jun and fos dimerize to form AP1 factor that binds to a sequence on DNA containing PyPuGACGTCNNNNGAGGTCPyPU. In esophageal cancer cell lines there is no expression of the fos gene. ...
5
votes
2answers
85 views

Bee identification

Can anyone help identify this UK bee? The picture was taken in June 2016. Doesn't have to be exact, really just want to know if it's a honey bee or a solitary bee. Thanks.
1
vote
2answers
61 views

Can a small polypeptide fold over itself and have a tertiary structure?

What I want to know is if polypeptides (those which are not considered as proteins) can also "exhibit" a tertiary structure.
1
vote
1answer
36 views

A New Antiviral Drug Strategy?

I am studying viruses and I have a question about antiviral drug strategies. Why haven't researchers tried finding small molecule drugs that will bind to receptors on the host cell, thereby preventing ...
1
vote
0answers
29 views

After a bacterial infection is dealt with, do any of that colony of bacteria remain?

Suppose that I get a bacterial infection, which my immune system deals with. Are there any remnant bacteria, or are they all gone? Now consider the same scenario, but having been treated with a full ...
2
votes
0answers
23 views

Can the respiratory quotient be calculated from a formula or must it be measured directly?

I found the following question on the Respiratory quotient: A normal human diet has a Respiratory quotient (RQ) of approximately 0.85. Given that pure oxidation of fatty acids has a Respiratory ...
1
vote
1answer
24 views

Thyroid hormone metabolism and excretion

My understanding is that hormones generated by the thyroid gland, including, for example, T4, are excreted and recirculated in the body through the digestive tract. The reason for thinking this is ...
3
votes
0answers
20 views

Phase Transitions of Purified Proteins

Why do solutions of purified protein condense into droplet phases? I'm trying to understand the protein phase transitions. Here is the article http://www.cell.com/cell/fulltext/S0092-8674(12)00634-4#...
3
votes
0answers
25 views

What is the effective population size of a simple two deme metapopulation?

I am confused as to how to compute the effective population size $N_e$ of a theoretical structured population. Let's consider here a simple case study. Imagine a 2-deme metapopulation. Each deme is ...
3
votes
1answer
52 views

What happens when the parietal cells of gut epithelium becomes partially non-functional?

The options are a) The pancreatic enzymes will not work properly b) The pH of the stomach will fall abruptly c) Steapsin will be more effective d) Proteins will not be adequately hydrolysed by ...
0
votes
0answers
17 views

Do Tumor-Infiltrating T Cells Experience Any Prolonged Effects Due To Hypoxia After They Return To Normoxia?

Adoptive cell transfer (ACT) therapy using tumor-inflitrating lymphocytes (TIL) is at the cutting edge of immuno-oncology treatments involving metastatic melanoma and other indications (1). The idea ...
5
votes
2answers
8k views

What factors are known to affect evolution?

My understanding is that the possible mechanisms of evolution are: Environmental changes Cultural/mating preferences Population Immigration Genetic Mutation Am I missing anything? I've heard that ...
0
votes
0answers
15 views

Lymph nodes Vs Lymph masses

what is the difference between lymph nodes and lymph masses as both have lymphocytes so I think ambiguously that they are same? If so, why different terms are used for them?
4
votes
1answer
51 views

Do flowers transpire?

I have googled this out but no where found a satisfactory answer. The definition of transpiration states that it is the evaporative loss of water from the aerial surfaces of the plant but I am really ...
0
votes
0answers
43 views

Is there an evolutionary advantage associated with migraine? [duplicate]

I have read Wikipedia article on Genetics of migraine headaches and I don't buy it Because genetics influence susceptibility to migraine, it can be shaped by evolution. Fitness-impairing ...
4
votes
1answer
58 views

Trying to identify an insect

Toady a friend saw an insect in his garden, in the UK (England). It looks like a combination of a hover wasp, a wasp and a dragonfly. Whist flying, I'd describe it more similar to a dragonfly. I've ...
1
vote
2answers
93 views

Why do FSH and LH hormones drop in diagram when maturing follicle and does size of follicle change during menstruation phase

There are three phases in menstrual cycle. In follicular phase of menstrual cycle, the level of FSH and LH would rise because they would stimulate ovarian follicle to mature. However, when I check ...
1
vote
0answers
45 views

What types of species can produce genetically identical offspring? [closed]

Talking about identical twins, triplets, etc. I'm curious which types of species are able produce genetically identical offspring. Let's limit the scope to species that reproduce sexually and ...

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