4
votes
2answers
57 views

How are ions 'pumped' across a membrane during electron transport?

A number of sites (including this one) that provide descriptions of photosynthesis state that high energy electrons 'pump' ions across a membrane. What is the actual 'pumping' mechanism? I've looked ...
0
votes
1answer
197 views

Where does female ejaculate actually originate from?

It's common knowledge that it's released via the urethra, but where does it originate? If it doesn't come from a part of the clitoris, then why is the clitoral glans called the clitoral glans? How ...
3
votes
1answer
124 views

Is this a grackle with an unusually long decurved bill (Phoenix AZ, USA)

Can someone help me identify this bird (sorry only had the iphone)? It looks like a grackle, but the bill is much longer than any I have seen. The bill looks like a Le Conte's thrasher, but it was all ...
-1
votes
0answers
22 views

Genetics behind Preimplantation genetic diagnosis (PGD) [on hold]

Preimplantation genetic diagnosis (PGD) is a screening test used to determine if genetic or chromosomal disorders are present in embryos produced through in vitro fertilization ...
1
vote
1answer
17 views

Once in the membrane, why don't proteins move?

I understand that based on their tertiary structure, intrinsic proteins have Hydrophobic [polar] R - Groups on their Surface and that they 'interact with the hydrophobic core of the cell membrane to ...
0
votes
0answers
9 views

Is there any range for Aortic Valve Gradient?

I understand aortic valve gradient is pressure on the value (measured in mmHg). What I would like to know is if there has been any research that identified a minimum and maximum pressure value as the ...
1
vote
1answer
25 views

Programs/software to graph biological data

I am curious about what sort of programs people in my field of academia are using to graph their data. I am a master student in biochemistry, and have more or less only used excel (on rare occasions I ...
0
votes
0answers
7 views

Effect of increasing Extracellular Na+ Concentration on resting voltage and likelihood of an action potential of occuring

If you increase the extracellular Na+ concentration how will this effect the resting voltage and likelihood that an action potential of will occur? Please explain using the Goldman–Hodgkin–Katz ...
2
votes
1answer
127 views

Mutation-drift equilibrium and among loci variance in heterozygosity

At mutation-drift balance, the increased heterozygosity brought by new mutations is exactly equal to the loss of heterozygosity due to genetic drift. At equilibrium, the expected heterozygosity for a ...
7
votes
3answers
97 views

Following DNA replication during S-phase of the cell-cycle, are all genomic regions subjected to the same stringent level of DNA-Repair?

To my (limited) understanding, there are 2 main ways that mutations can occur in DNA: Environmental (UV, etc) and mistakes during cell division. I was wondering if there is a mechanism that can give ...
14
votes
4answers
2k views

Book recommendation on population/evolutionary genetics?

I have recently been involved in collaborations that require me to model the population genetics of eukaryotic populations. I fear I may either be "re-inventing the wheel" or making conceptual ...
2
votes
1answer
55 views

How much genomic variation one usually find within a given bacterial species?

If I find the exact starting position (say 1152471) of the coding sequence of a given gene in the genome of a bacterium, is the genome of the bacterium in general stable enough so that I can expect to ...
0
votes
0answers
11 views

Guide to learning about Population biology / ecology / dynamics for a non-Biologist

I'm an applied mathematician who works in the field of feedback control systems but has been becoming interested in looking at population biology (e.g. Lotka-Volterra, Mathusian growth,etc.) from a ...
-3
votes
1answer
37 views

Why are considered to be exceptions to the cell theory?

If I am not mistaken, the cell theory states that: All living organisms are made up of one or more cells Cells are the smallest units of life Cells arise from pre-existing cells Aseptate fungal ...
4
votes
3answers
44 views

B-cell antibody production

I've just learned about B cells in immunology lectures and some things are not clear to me. Here's what I know: 1) Apparently, each B cell produces a specific antibody, determined randomly at the ...
17
votes
1answer
732 views

Additive genetic variance components from LMER in R

I've set up some dummy data in R which makes 40 genetically related lines, they are all siblings within a line so are genetically related by a factor of ½ thus additive genetic variance should be ...
-4
votes
2answers
27 views

Why can't proteins make copies of themselves? [on hold]

Why is it impossible for proteins to make copies of themselves?
1
vote
1answer
23 views

Why is the left hand bigger than the right hand?

I've noticed that the left hand is bigger than the right hand, more precisely - I don't know whether it is really bigger or just more flexible? I compared the hand span of the left hand and right ...
-2
votes
0answers
27 views

Why has DNA evolved into a double helix? [on hold]

What is the reason that DNA evolved into a double helix? Does it still evolve?
0
votes
0answers
3 views

Do antagonist-receptor complexes get absorbed into the cell?

My understanding is that normally, a neurotransmitter binds to a receptor and then that ligand-receptor complex gets absorbed into the cell and either degraded or recycled. So does the same thing ...
-5
votes
1answer
33 views

Is DNA of all animals made of the A,T,C,G blocks? [on hold]

Is it true that DNA of all animals is made of the A,T,C,G blocks?
0
votes
0answers
23 views

What makes DNA sequences most different/recognizable from a biological perspective?

We can pretty easily quantify the amount difference between two different strings/sequences of characters. For example, if we take the words trebuchet and trebucket, we can say they have a Levenshtein ...
1
vote
1answer
69 views

What does NaOH do for the plating of Bacillus subtilis?

A book called Molecular Biological Methods for Bacillus called for plating Bacillus subtilis cells on LB-agar plates with the following components: A general-purpose medium containing per litre: ...
0
votes
0answers
12 views

How to search for all human diseases associated with a inversion on chromosome 22?

I know that a deceased relative had a genetic test made that showed a result of a Chromosomal inversion on chr22 but I don't know what type and where is the inversion until I get the full medical ...
2
votes
1answer
1k views

Why does air from the nasal cavity not go into the oesophagus?

When we ingest food, the epiglottis covers the trachea and the uvula covers the nasal passage. But what happens when we breathe? Why does the air go into our trachea and not the oesophagus?
1
vote
0answers
12 views

Can plant roots absorb dissolved oxygen from water, or do they require actual bubbles in the water?

Plant roots generally require some exposure to air. Deep water culture is a form of hydroponics where plants' roots are left to soak in water. To keep the roots from "suffocating", most online ...
2
votes
1answer
67 views

Ancestral Allele and Hapmap

I notice on dbSNP rs6352 has an ancestral allele of G - http://www.ncbi.nlm.nih.gov/SNP/snp_ref.cgi?rs=rs6352 The hapmap in humans for this allele is very rare, the homozygous version practically not ...
13
votes
4answers
12k views
+50

Why deoxyribose for DNA and ribose for RNA?

Why is DNA made out of deoxyribose and RNA made of ribose? Why can't they both use ribose or deoxyribose? I think that the deoxyribose gives an advantage in storing genes, the job of DNA and ribose is ...
0
votes
0answers
13 views

T7 vs pBAD promoter strength

How does pBAD and T7 promoter strengths compare when pBAD is induced under conditions which would lead to its highest strength? Are there any papers that compare the two inducible promoter systems?
2
votes
2answers
36 views

Why upper surface of leaves is more green and shiny than the lower one?

I have properly googled this and got various answers. However, those answers do not provide an answer to the "Why" part of my question. Why is it that the upper surface of leaves is more green than ...
2
votes
1answer
409 views

Could potatoes that have been fridged for 142 days still sprout afterwards?

I know that potatoes can still sprout even after being fridged, but could you fridge them for 142 days without them decomposing, and still be able to use them as seeds to grow more plants after that? ...
0
votes
0answers
15 views

How does the body know to stop effector cell proliferation?

After a pathogen has been successfully neutralized, effector cells such as the plasma cells and the cytotoxic T cells which are specific for that pathogen decrease in numbers. What is the signal in ...
2
votes
1answer
45 views

Can galls be formed from mutualistic relationships?

According to Wikipedia, galls (cecidia) are formed by parasitic insects and mites like gall wasps (Neuroterus albipes). At some metamorphic stage, these organisms alter cell division processes in ...
2
votes
0answers
48 views

How does the introduction of clones would affect population genetics? [on hold]

Since the ability to clone animals gives another way to preserve species, this could help for the breeding process. It has been noted that with the ability to clone animals, endangered species can ...
2
votes
1answer
2k views

Does a woman contain all the genes needed to make a man?

I know the answer of inverse is at here, but how about this question? I also read this question, can I imply to human that a woman also contain all the genes needed to make a man? Edit: ok , I ...
0
votes
0answers
10 views

How important is dead wood to the ecology of a forest

I have a local 'forest management group' in my area. One of the jobs they do is to thin out the forest by removing some of the trees. They then sell the wood for firewood. I want to tell them to ...
1
vote
0answers
20 views

What's the exact meaning of and how to derive the coefficient of the path from sire to offspring?

According to Wright's Coefficients of Inbreeding and Relationship, the coefficient of the path from sire to offspring is given as $p_{o \cdot s}=\frac{1}{2}\frac{\sqrt{1+F_s}}{\sqrt{1+F_o}}$ But ...
1
vote
1answer
44 views

Which mammals cannot synthesize taurine?

It is fairly common knowledge that domesticated cats cannot synthesize the compound taurine. Other mammals seem to be able to synthesize taurine from cysteine [source]. Are there other mammals that ...
0
votes
0answers
13 views

DNA. mRNA, tRNA [on hold]

Can someone explain to me how transcription and translation works, especially the part about codes. And does amino acids has code or is it the tRNA?
0
votes
0answers
7 views

Are there well studied examples of ERAD-mediated membrane insertion, especially from viruses?

Membrane insertion of transmembrane proteins typically requires highly hydrophobic alpha helixes at the N-terminus, N-terminal signal peptides, tail anchors, or a combination of the three. Byun, H., ...
4
votes
1answer
124 views

Selection Pressure on Orca Whale Coloration

What is the proposed selection pressure that leads to the distinctive coloration of Orca whales? I can find nothing in the literature.
-4
votes
0answers
36 views

What is PCR kinetics? [on hold]

What is PCR kinetics and the application of PCR kinetics? What are the types of graphs are required and how can we interpret the graphs?
0
votes
2answers
57 views

What is the frequency distribution of each base in a DNA sequence?

Can we say that the frequency distribution of each base in a DNA sequence is equiprobable? After the negative answer; i rephrase: Is there a use case in which the frequency distribution of the ...
0
votes
0answers
7 views

cellular chemical changes during mitosis [on hold]

How exactly, in terms of molecular behaviour/structure, do condensins, and cohesin s [in cell mitosis] achieve their functions within the cell?
3
votes
1answer
103 views

What's the (or some of the) minimum(s) amount of atmospheric carbon dioxide needed by plants?

We currently have a problem of increasing CO2 in the atmosphere. But assuming we find a way to carbon sink it, what is the minimum CO2 we need to leave in the atmosphere to provide a source for ...
-2
votes
0answers
26 views

Why did earlier humans not survive, yet apes are still among us? [duplicate]

Why did the earlier species of humans, such as the Ardipithecus and the Homo erectus, not survive, but the ape and chimp species, with whom we share 98% of our DNA, are still surviving and among us. ...
0
votes
0answers
8 views

How to Stabilize Histamine Surges in Exercise of MD/DMII?

I am studying how to stabilize histamine surges/effects without antihistamines in exercise of Metabolic Syndrome (MD) and Diabetes Mellitus II (DMII). Generic/simplified case: Symptoms in exercise: ...
1
vote
2answers
37 views

What did cyanobacteria gain from photosynthesis?

As far as I understand, cyanobacteria began performing photosynthesis long before plant cells as we know them arrived on the scene. But cyanobacteria do not seem to use polysaccharides in the same way ...
4
votes
1answer
260 views

How significant is the genetic component of homosexual behaviour?

From some basic googling, I found that nobody has ever proven that people are born gay and that environment plays a great part in homosexuality. I wish to know if there is a genetic component to ...

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