2
votes
0answers
76 views

A number of questions regarding chemotaxis assay using PBMCs

In our lab we would like to study the chemotaxis of PBMCs towards conditioned medium obtained following treatment of cancer cells with different compounds. My questions are regarding the method of ...
0
votes
1answer
9k views

How reversible is decerebrate posturing caused by brain stem damage?

This is a follow-up question to How likely would Abraham Lincoln be to survive his wounds today? You don't have to see a CT scan or autopsy to know if the brainstem is injured (directly or ...
2
votes
1answer
100 views

.Net DNA/Codon Parser

Does anyone know of an .NET (C#,VB.NET, maybe F#) DNA parser? If not I will probably make one, it doesn't seem like it would be hard. My general idea was to generate something that would report the ...
4
votes
2answers
74 views

Transmission of disease from mother to fetus

Can parasite, microbes be passed from mother to fetus through the placenta ? I know some like HIV can be.
1
vote
0answers
25 views

How is saltatory conduction faster than conduction of unmyelinated fibers? [duplicate]

It's always the same explanation that currents are able to "hop" along Ranvier nodes instead of passing continuously along the axon making saltatory conduction more efficient than continuous ...
3
votes
1answer
515 views

Why re-label the strand ends in 3' DNA labelling?

I have a problem with a molecular biology question; I don’t understand how DNA 3’ labelling works. I took a diagram from my lesson and tried to understand with it; this is what I understood. If I’m ...
10
votes
1answer
149 views

Are there specific conditions that allow humans to see ultraviolet wavelengths

It is fairly common knowledge that the lens in its normal state absorbs ultraviolet (UV) radiation. An interesting notion has come up from time to time in my reading that suggests there are a small ...
0
votes
1answer
40 views

Cellular components of blood cells

There are different types of blood cells in the human body i.e. red blood cells, neutrophils, basophils, eosinophils, monocytes, T-cells, B-cells. What are the cellular components of these cells? ...
5
votes
2answers
110 views

There are linear and rotary molecular motors in the cells. Do any of them have a fixed or stable frequency or speed?

Are there any linear, rotary or oscillatory molecular motors in the cells which can have fixed frequeny and which can be used as a reference for elapsed time timer? This question is with relevence to ...
1
vote
1answer
134 views

Why do I have a lot in common with my mother? [closed]

I have not spoken to my mother in 15 years but recently connected with her and her side of the family. I was primarily raised in a different sub-culture after the age of 4. As it turns out I ...
2
votes
2answers
76 views

Termination of translation

What dissociates first - the last tRNA, mRNA and release factors or the subunits of ribosomes? I tried searching this from Lehninger but couldn't get a clean answer.
1
vote
1answer
63 views

What is the strength of human cornea?

What is the difference of pressure a human eyeball cornea (cornea, lens and other elements separating vitreous body from air) can handle? Or asking differently: what the outside pressure should be to ...
2
votes
1answer
43 views

How essential is vitamin B3 to the diet?

I know this might seem contradictory since by definition a vitamin is an essential part of the diet but I have read that nicotinamide, a form of vitamin B3, can be synthesised from L-tryptophan. Is it ...
-2
votes
1answer
101 views

What are uses of fossils? [closed]

What are the geological uses of fossils and how could it be utilised? From The Institute for Creation Science: Fossils are typically found in sedimentary rock, almost all of which were originally ...
2
votes
1answer
45 views

How can a respiratory infection lead to a skin infection?

Example of a case: 5 children develop a bright red rash on the face and turns violet after a few days and then disappears. Then maculopapular rash appears on the trunk, buttocks and extremities. It ...
2
votes
1answer
58 views

Antibody production in secondary immune response

Can IgG antibodies be produced in the secondary immune response without the help of T cells? Is the affinity of antibody for antigens higher during secondary immune response?
3
votes
1answer
158 views

Number of genes required to sustain life

Are there estimates of the minimum number of genes required to sustain life? In what I mean by life here, I don't include viruses.
4
votes
1answer
66 views

What is the advantage of the way eukaryotes initiate translation?

The eukaryote and prokaryote mechanism for translation is slightly different. Is there any advantage of the eukaryote translation mechanism ? Edit : I specifically want to know why eukaryotic ...
2
votes
1answer
2k views

What negative effects can pinhole glasses have on the body?

While shopping in the local supermarket yesterday, I was surprised to find this display on one of the shelves. I also realize that I should have taken a pamphlet with me, as well as a picture of ...
14
votes
3answers
3k views

What causes the development of antibiotic-resistant strains of bacteria?

I understand bacteria have become resistant to antibiotics due to selection pressures, but how do resistant bacteria process antibiotics when exposed to it, compared to non-resistant bacteria. Also, ...
2
votes
2answers
174 views

Accuracy of a particular genetics test

I am a newbie in biology and I am simply trying to discover the field of genomics. Consider the question - Are genetic tests accurate? I don't believe they are as the genes may not provide the ...
-6
votes
2answers
217 views

Is love biologically useful?

I thought about this statement a while ago: Natural selection sucks, it says those who love too much (or too many) will die the easiest and fastest. Sad but true. Only family (biologically of ...
3
votes
1answer
63 views

Alternating Ovulation

I have often heard that right and left ovaries alternate in releasing ovum. Is it always true? What controls this rhythm? Is it simply because the other ovary is unresponsive to LH or FSH? If so, ...
3
votes
1answer
53 views

Number of MHCs in neurons

I have read that neurons have proportionately less MHC molecules than other cells of the body. What is the advantage of this?
1
vote
1answer
42 views

Variation in MHC in humans

What evolutionary process lead to so much variation in MHC? What is the advantage of having such variation?
5
votes
1answer
50 views

A possible cause of autoimmunity

I read that Doherty and Zinkernagel found that MHC- heterozygotes present more antigens to the immune system than homozygotes; yet, the infected heterozygous mice in their experiment all ...
2
votes
1answer
163 views

Can antibodies be formed against white blood cells after blood transfusion?

If antibodies are produced against other blood groups' red blood cells, why can't antibodies form against white blood cells, of any blood group? (even the same one, as MHC will be different in almost ...
2
votes
0answers
92 views

What to do with a DNA sequencer? [closed]

My school is very fortunate to have a DNA sequencer, and I want to find an opportunity to learn how to use it. I'm currently taking AP Biology this year, and I hope to do an independent study in ...
0
votes
5answers
283 views

Is evolution true as Darwin said? [closed]

I was telling the theory of evolution to my friends. But they asked me for the proof. They said, we are not seeing any such transition species at present. Neither we have such evidence for evolution. ...
0
votes
2answers
1k views

Genetically speaking, are dogs exactly similar to humans and chimps both?

Richard Dawkins mentions in his book The Greatest Show on Earth that dogs are exactly similar to both humans and chimps. Supposing that a cell contains the genetic similarity between 2 species, he ...
8
votes
1answer
3k views

Why can't humans drink sea water?

Why can't humans drink sea water? It would seem to be a huge evolutionary advantage for an animal to be able to drink sea water rather than have to rely on fresh water, and it's provably not ...
5
votes
0answers
211 views

Cytoplasmic determinants - protostomes and deuterostomes

Cytoplasmic determinants are spread unevenly in the egg, and so when embryo starts forming (cells start dividing), the determinants are also unequally divided between cell. This unequal distribution ...
1
vote
1answer
102 views

Creative ways to deactivate alpha-amylase taken from fungi

I can deactivate $\alpha$-amylase in ways such as extreme temperature controls, pH controls of the solution it stays in, or adding salt to the solution. However, are there any other unique or ...
4
votes
1answer
120 views

How are blood vessels affected by UV and infrared radiation?

The lining of the blood vessel as an interface and boundary layer is of existential necessity to the life-support of mammals. My question is: How are major blood vessels and the blood vessel lining ...
4
votes
2answers
116 views

Why don't amino acids get linked in the functional groups of acidic and basic amino acids?

There are 'acidic' and 'basic' amino acids like aspartate and histidine. When protein is synthesized with those amino acids, what ensures that the to-be-assembled amino acids will not bond to the ...
3
votes
1answer
353 views

Negative value on linear gene expression in microarrays

I am starting to use microarrays and maybe this is a dumb question: Using Illumina microarrays, linear gene expression can be negative? Or maybe some artefacts have been introduced? And, in this ...
4
votes
1answer
114 views

Does the body lose energy or gain energy relatively when drinking or eating hot things?

Does the body lose or gain energy when drinking or eating hot things compared to more neutral temperature things? On the one hand, The body could somehow convert the heat energy into human usable ...
3
votes
1answer
297 views

What happens in your brain when you receive information which causes you to bristle?

I'm talking about moments when you watch a film and you bristle, or when you listen to music, etc. What kind of neurotransmitter flow changes?
5
votes
1answer
248 views

Why does strenous exercise cause vision of “lights”?

I had a hard climb a week ago. I got so tired then any time I closed my eyes I saw these lights inside my head. I see these lights almost every time that I run fast or some thing like that. What are ...
2
votes
1answer
48 views

Phenoptosis, behavior evolved for good of species?

I was reading this and felt like the argument is being made that organisms die for the good of species. Isn't this nonsense? This especially bugged me: "'Age-induced, soft, or slow phenoptosis'" ...
0
votes
1answer
100 views

Lizards are sometimes called cold-blooded because they depend on their surrounding temperatures to keep them warm.

Predict how the composition of the cell membrane of a lizard might change from winter to summer. Justify predictions. Can someone please help me figure this out. Does it have to do with fluidity?
1
vote
1answer
34 views

Genotoxic agent and their metabolic pathway

What are the mechanics (set of biochemical reactions) allowing a given genotoxic agent to modify the mutation rate at a given spot? to induce only a given type of mutation (from Gs to Cs for ...
4
votes
3answers
403 views

What are the benefits of elucidating the crystal structure of a protein?

I have spent months as a student working on trying to form a tricky protein crystal. But I have never actual had explained to me why the structure will be useful. Once elucidated, what can we ...
3
votes
3answers
164 views

Blood pressure during exercise

What happens to blood pressure when we exercise? Does it increase, decrease, or remain the same? If it does increase, why are patients with high blood pressure recommended to exercise?
5
votes
2answers
204 views

How to get smallest subtree containing a set of nodes from BioPhylo?

I'm testing out various phylogenetic libraries in Python. I want to read in a Newick tree, then, given a list of taxa, generate the smallest tree that contains them all. This task is quite simple and ...
6
votes
2answers
623 views

Methods of nuclear transfection - nuclear transport

I am reading through the ENCODE papers, which is taking me well out of my comfort zone in terms of modern laboratory techniques. At the risk of asking a question which may well be thoroughly answered ...
5
votes
1answer
240 views

Variations in Genome Sizes

Why is there wide variation in genome size amongst groups of protists, insects, amphibians and plants, but less variation within groups of mammals and reptiles?
6
votes
1answer
162 views

Puffball mushroom species ID?

Found this mushroom today. It's a kind of puffball mushroom and I think pestle puffball but I hope someone can confirm that/point me to other likely species. It was in Central Eastern Sweden ...
3
votes
1answer
304 views

Are there any 6 limbed reptile fossils?

Were any 6 armed "tetrapod" fossils ever found? I've seen some lobe finned fish with two sets of shoulders in an evolutionary bio book... I'm curious because I'd like 4 limbed and 2 winged dragons to ...
2
votes
0answers
51 views

Natural selection and the Galapagos Islands [closed]

Woodpeckers found on the South American mainland are able to peck insects from the bark of trees. Would the woodpecker finch have been able to survive if woodpeckers had found their way to the ...

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