0
votes
0answers
16 views

What is the effect of antibiotic chloramphenicol on bacterial size?

When low amounts of antibiotics like Chloramphenicol is added in a bacterial culture, the steady-state growth rate decreases but what happens to the steady-state size? Can anybody please refer me to ...
3
votes
0answers
126 views

Cause-and-effect questions about growth and development of plant

I need to solve some cause-and-effect problems. The problems are related to growth and development of plant. "Growth and Development" chapter is the first chapter in third level of high school (senior ...
13
votes
1answer
2k views

How does a tree trunk sprout and grow after being cut?

After I cut trees into logs and remove the branches in winter, they start growing. They sprout out and grow completely normal looking stems and leaves and maintain them all summer. The sprouts mostly ...
2
votes
2answers
279 views

Can the human body enter “Power Save” mode? [closed]

Once a year, I am fasting for 24 hours. No food or drink at all for whole 24 hours. Recently I thought about what is happening to me during those 24 hours, and realized there might be something ...
4
votes
1answer
134 views

Spider Identification Illinois

I noticed a really huge, beautiful web on my porch last week, and tonight, I discovered its resident. I'm thinking it's a Araneus diadematus (Cross Orbweaver), but was hoping for some confirmation. ...
5
votes
1answer
286 views

What kind of insect is this and what is it doing?

I live in Denmark, Europe and found these 2 insects on a tree. I'm interested in the big fly and have the following questions: What kind of fly is it? What is it doing with the little fly?
5
votes
2answers
237 views

Energy released during the production of ATP?

When glucose is used during aerobic and anaerobic exercise, how much energy is expended or required? During aerobic exercise: $C_6H_{12}O_6 + 6 O_2 \to ATP + H_2O + 6 CO_2$ + energy During ...
1
vote
0answers
59 views

How do ants protect themselves from their own acid? [closed]

How do ants get the formic acid in their sting? I mean, which cells produce it, and how are these cells protected from their own product?
5
votes
2answers
132 views

Is it harmful for someone to consume things full of bacteria if they don't get physically sick from the bacteria at all?

Or as another example - what if you touch a surface that's contaminated with potentially pathogenic bacteria (like the ones at http://arstechnica.com/hardware/news/2008/05/study-keyboards-make-...
3
votes
2answers
82 views

Can anyone ID this flower plant by the photo?

Can someone identify this plant? It has big red flowers when it flowers! Not sure if it is native, but it is in my grandmothers garden in Vancouver, British Columbia, Canada.
3
votes
1answer
125 views

Why do cats like enclosed spaces (e.g. boxes) so much?

A recent article doesn't reach a firm conclusion, but offers two possible explanations. Hiding is a behavioral strategy of the species to cope with environmental changes and stressors. It ...
0
votes
1answer
36 views

What kind of tree is this?

I live in Denmark, Europe and was going for a walk on a beautiful cemetary in the city. I saw this tree and would like to know what species it is. Unfortunately i have no photos of the tree from a ...
12
votes
4answers
287 views

How does the molecular machinery choose where to cut a chromosome for recombination?

I'm wondering about a few technicalities of crossover in meiosis. The point of crossover is to create new chromosomes that don't have the same allele combinations as the original two chromosomes. ...
0
votes
0answers
67 views

Geographic/ethnic distribution of Neanderthal DNA in modern humans

There is a really good chance that various human populations have different levels of Neanderthal DNA in their genes. And yet, the only thing I was able to find is the percentage of Neanderthal DNA ...
1
vote
0answers
91 views

Listing Cluster of Differentiation (CD) markers (immunology)

I hope this question is appropriate for this SE. When listing multiple cluster of differentiation (CD) markers to define a cell population, e.g. CD3+CD8+CD45+CD4-, is there a default order to put them ...
4
votes
3answers
376 views

Modern immunology textbooks

I am looking for recommendations to good textbooks introducing modern immunology. Review articles, preferably modern (post 2000) would also be useful. Please, include a brief comment with each book ...
1
vote
0answers
25 views

Is it possible to biologically convert potential energy to chemical energy?

To lift an object x meters it is necessary to expend, at a minimum, an amount of energy corresponding to the increase in that objects potential energy associated with the increase in height. When ...
2
votes
1answer
600 views

Does pH affect Michaelis constant?

I have been trying to confirm the Km of a substrate (which is 34 +/- 4 mM). This value was obtained in 50 mM MOPS, pH 6.3. I conducted my kinetics assay in a buffer of pH 7 and obtained a Km value in ...
0
votes
3answers
183 views

Why didn't humans evolve to reproduce identical twins all the time?

According to the selfish gene theory, it seems like because identical twins sometimes get produced, a mutation to a gene that says, "if you have an identical twin, be fully altruistic towards them" ...
3
votes
0answers
45 views

dominance coefficient, why (1+k)?

I'm trying to get a better understanding of quantitative genetics by reading Lynch and Hill 1986. I'm getting stuck with some notation that's used right at the beginning referring to the mutant and WT ...
0
votes
1answer
445 views

why didn't natives of south america evolve darker skin?

I understand that darker skin tone is caused by melanin which helps to protect against the extra UV radiation that comes from more direct sunlight. It evolved in Africa before we migrated away from ...
0
votes
1answer
38 views

What is the difference between Ostracodermi and Placodermi

I looked the word origin and found Placodermi is PLATE SKINNED while Ostracodermi is Shell Skinned. Can you please explain the difference between being Plate skinned and Shell skinned?
2
votes
1answer
55 views

Can anyone identify this plant from Bangladesh?

I have taken the picture from an agriculture university in Bangladesh.
7
votes
1answer
120 views

What is cross-immunoreactivity, and how does it impact vaccine development?

What I understand about cross-immunoreactivity is that the antibody induced by one specific antigen is also fairly effective against another antigen. How would this be used for vaccine development? ...
1
vote
1answer
426 views

When does DIFFUSION occur and not OSMOSIS, and the otherwise?

For example, I do know that red blood cells have both the Na+/Cl- co-transporter and Aquaporin (water channel) that allows both Na/Cl and water molecules to pass through. But why in biology textbooks ...
0
votes
0answers
48 views

How did the tendency to perform death rituals evolve?

Both elephants and humans perform rituals when deaths occur. However, I do not see any evolutionary benefit of this. The rituals take time, which apparently could be better spent hunting, foraging, ...
1
vote
2answers
132 views

Definition of “essentially diploid”

While researching the F12 cell culture medium (Ham, 1965), I came across the term "essentially diploid Chinese hamster ovary cells". The terms "subdiploid" and "near diploid" were also used to refer ...
0
votes
0answers
34 views

Normalise protein database domain-wise

Suppose we've collected a big (hundreds of thousands) library of different protein sequences with certain features. Then we want to use this data base to train a classifier. And for several ...
0
votes
0answers
127 views

How to model missing residues on a protein from multiple PDB files?

I have multiple X-ray structures (PDB files) of the same protein. All of them have missing stretches of residues. I want to use all of them to build a single model, with as little missing residues as ...
1
vote
1answer
72 views

How does the brain regulate its temperature?

I recently ran into a bio-physical paradox while trying to solve an engineering problem, using nature's way as a guide; namely the brain. I'm working on designing a totally new system of liquid/gas ...
1
vote
0answers
14 views

Biomolecule , DNA-RNA difference [duplicate]

Why is that a RNA has uracil in place of thymine? RNA could have thymine bases but it has uracil ? What is the reason for the presence of uracil there ?
2
votes
1answer
289 views

Can cooking oil kill fleas?

I cannot find a reliable way to kill fleas after removing them from my cats with a flea comb. Soap and water does not do the job and they climb back out of the drain. Will cooking oil suffocate ...
0
votes
0answers
29 views

Chromosome 17-Ancestry question

I did the 23andme genotyping and was going over my ancestry. I mostly have ancestors that came from the UK which dominates most of my chromosomes. However, just a little bit (~1.4%) of my DNA is ...
2
votes
1answer
15k views

How are the paranasal sinuses linked with the capillaries in the ear canals?

Sinus congestion often seems to be accompanied by excess pressure on the outer ears (as anyone who has shared a transcontinental flight with an infant can attest to) or fluid buildup in the canals. ...
0
votes
1answer
54 views

What is the mechanism by which bactericides kill bacteria? [closed]

"Bactericides kill bacteria". What is the meaning of "killing" in this context, and how exactly is this "killing" happening chemically?
0
votes
1answer
213 views

Why do almost all SNPs have two alleles?

Reading the Wikipedia page for SNPs I find the sentence "Almost all common SNPs have only two alleles." This is consistent with terminology elsewhere, such as the therm "Minor allele frequency", which ...
1
vote
1answer
124 views

How do signal transduction pathways utilize transcription factors to express a specific gene?

I have an inquiry regarding the regulation of genes via extracellular signaling. To my knowledge, in autocrine, paracrine, and endocrine cellular communication, large protein ligands that cannot ...
1
vote
0answers
142 views

How can we determine the polarity of fat molecules?

I'm trying to solve a question in a biochemistry quiz, which is asking for classifying a set of lipidic derivatives, by increasing polarity. Unfortunately, we didn't cover the classification of ...
0
votes
0answers
33 views

Why are diabetes patients usually overweight when they don't even use the glucose?

Diabetes is a condition where either you are insulin resistant and therefore produce less insulin than usual or you don't produce insulin at all. Insulin is the "key" to the cell's "sugar lock" which ...
1
vote
1answer
701 views

Why do sneezes come out the mouth?

As anyone who's ever sneezed can tell you, it's caused by irritation in the nose. And the answer to a question on this very SE attests that "sneezing is a reflex, partially autonomous, to clear the ...
1
vote
1answer
144 views

Please explain what a gene isoform is in lay terms?

I am a physicist by training, however I am now doing computational biology research. I know what genes, DNA, proteins, enzymes, introns and exons are. I sort of understand how DNA is used to create ...
0
votes
0answers
52 views

Proteins and Blood Acidification

Is there evidence to suggest that excessive consumption of Whey, or similar proteins will lead to acidification of the blood?
0
votes
1answer
37 views

E value cutoff for RNASeq search

I am trying to narrow down the possible search criteria from an RNASeq experiment. I already have the cds sequences so I took these and used Blast+ program to blast the data against itself to find ...
2
votes
1answer
161 views

Looking for university/graduate-level texts on RNA

Although I was not a biology major in college, I took the biology introduction sequence, as well as organic chemistry and biochemistry. I would like to learn more about RNA and ribozymes. What texts/...
6
votes
2answers
8k views

How hot can a beverage get without burning the tongue?

What is the maximum temperature that a beverage can be without burning the tongue? I suspect there's a maximum temperature that the surface tissue of a tongue can withstand without being damaged (...
3
votes
0answers
308 views

How much salt [NaCl] is too much in DNA precipitation?

In DNA extractions, how much is too much salt in a CTAB extraction buffer? Protocols hover around 2.5 molar; if you go over this (e.g. 25 molar), will you saturate your solution, and precipitate the ...
0
votes
0answers
138 views

Jurkat single cell clonal expansion

I'm hoping to do a clonal expansion of Jurkat, expressing my construct which is currently transduced virally. From the FACS data I currently have roughly 30-40% expression in my culture but I need it ...
2
votes
3answers
235 views

Why don't half of us have situs inversus?

I don't see any possible evolutionary disadvantage in situs inversus(the condition where major organs are mirrored from their normal positions) when people with situs inversus can have a normal ...
1
vote
1answer
65 views

How to synthesize and isolate single stranded cDNA from an RNA template?

I would like to have pure single stranded cDNA of my choice. I am thinking of reverse transcription from RNA (obtained by in vitro transcription), degrading RNA from RNA-DNA hybrid with RNase-H, ...
0
votes
0answers
26 views

At what temperatures does food burn the roof of your mouth? [duplicate]

Does anyone know the temperature at which the roof of the mouth burns? Are the degrees of burns the same as the ones for the epidermis?

15 30 50 per page