2
votes
2answers
2k views

Why does a blood test show ethanol when no alcohol was consumed?

Why would ethanol show up in a blood test if a person had not been drinking alcohol in many years. What are other reasons for showing ethanol?
2
votes
2answers
137 views

What does it mean to perform in vitro experiments with mutant bacteria?

I came across the following sentence while reading the paper: Nanchen, Annik, et al. "Cyclic AMP-dependent catabolite repression is the dominant control mechanism of metabolic fluxes under glucose ...
2
votes
1answer
2k views

Complementarity Determining Regions (CDRs)

Complementarity determining regions (CDRs) are part of the variable domains in immunoglobulins (antibodies) and T cell receptors, generated by B-cells and T-cells respectively, where these molecules ...
1
vote
1answer
36 views

Degenerate Alignment Analysis

Can someone please tell me what is Degenerate alignment analysis? Could not find a good article on the internet that could help me understand what it means? (I have not studied biology since last 8 ...
1
vote
0answers
33 views

TAA- Tumor associated antigen [duplicate]

An approach to find Tumor associated antigens is based on transfection of expression library made from cDNA into cells expressing desired MHC haplotypes. Can someone please explain what this line ...
1
vote
1answer
25 views

Microarray probe and target

In a microarray, which one is called a target and which one is the probe? the one that is added later , is that the probe or the one present in the slots of the microarray, that is the probe? (I have ...
2
votes
1answer
208 views

Why do moths not die when they fly into a window?

Sometimes at night when I'm inside with a light on, I can hear (I'm sure) moths fly into the window, and it's so loud I can sometimes hear it over the TV from the other side of the room. Since ...
7
votes
2answers
268 views

How does Natural Selection shape Genetic Variation?

Background Importance of the additive genetic variance As stated here, the fundamental theorem of Natural Selection (NS) by Fisher says: The rate of increase in the mean fitness of any organism ...
2
votes
1answer
48 views

Why can't NMR be used on large RNA molecules?

While reading my Molecular Bio textbook, I came across a sentence that stated that NMR cannot be used on large RNA molecules to determine their structure. Why is this? Is it because RNA is single ...
4
votes
1answer
60 views

Protein Isolation from mammalian cells

What non-SDS buffer can I use to isolate protein from mammalian cells? The protein is intended for testing electron transport chain complexes.
2
votes
0answers
165 views

Origin of the 260/280 ratio?

This is not a duplicate of all the other 260/280 ratio questions, I already know that DNA is supposed to be 1.8 and RNA is supposed to be 2.0. However, this might be more appropriate for chemistry, ...
2
votes
1answer
102 views

What's the mechanism behind 'losing heat through your extremities'?

I can understand how if you are not circulating enough (warm) blood, by not moving much while in a cold environment, your extremities themselves lose heat, and become cold - but I don't understand how ...
3
votes
2answers
128 views

Is there a difference between any of these terms for proteins: “crystal structure,” “NMR structure,” “solution structure,” and “complex structure”?

My homework wants me to plot all crystal structures determined per year, but when I search on PDB for all structures, many of the articles say "crystal structure," but some say "solution structure" or ...
6
votes
1answer
273 views

What does “Mutational Variance” mean?

Background The concept of mutational variance can be found in many articles including this one for example. The mutational variance of a trait number $i$ can be found in the M-matrix in position ...
2
votes
1answer
44 views

What roles do cyclooxygenase, lipoxygenase, and epoxygenase have in signal transduction? [closed]

Besides oxidizing fatty acids to form prostglandins, leukotrienes, and epoxides, what other roles do cyclooxygenase, lipoxygenase, and epoxygenase have in signal transduction?
7
votes
1answer
2k views

What about a bat's immune system protects them from Ebola?

Current evidence indicates that fruit bats are a reservoir host for Ebola. Has any research established what is different about their cell biology or immune system that reduces virulence for them? ...
10
votes
2answers
254 views

Did Darwin ever reach the conclusion that selection will remove variation?

According to simple models of selection the genetic variance in a population should be reduced by selection. (Fisher's fundamental theorem states that the rate at which a population can evolve is ...
2
votes
1answer
92 views

What is the classification for animals with full tube digestive tracts?

What is the formal name for animals with full digestive tracts, by which I mean a mouth and an anus, and what is the classification for animals that have a single hole for exchanging food and waste?
0
votes
2answers
1k views

Negative role of Placenta

How can a placenta turn hostile to the mother or fetus ? What are the abnormalities found during placental delivery ?
7
votes
1answer
421 views

How do birds influence brood sex ratios?

This paper concludes that birds can adaptively modulate brood sex ratios. How do birds modulate brood sex ratios? Are they somehow able to influence the sex of their young? Or once young are born, do ...
1
vote
1answer
37 views

Which sex is homogametic in side-blotched lizards?

I'm just trying to find out whether the male side-blotched lizard is the hetero- or homogametic sex in side-blotched lizards (Uta stansburiana) - some reptiles are ZW system (female heterogamete) and ...
0
votes
2answers
58 views

How is it that ionic diffusion is independent of other ions?

This question arises from the explanation of what the resting potential of a cell membrane is. In the Goldman formula, there is no interaction between different ion types. If diffusion is caused by ...
8
votes
2answers
1k views

Why is the current Ebola outbreak different from previous outbreaks?

I don't know if this question has an answer at this time, but I would like to know if there is some biological reason why the current Ebola outbreak is so much more complicated and widespread than in ...
3
votes
1answer
224 views

Why do we absorb vitamins better from whole foods than from pills?

We can't rely on pills to provide us our nutrients because we don't absorb the nutrients from the pills as effectively. Presumably this is because pills are lacking components that are required for ...
1
vote
1answer
69 views

What is this vinca like vine?

What is this vinca like vine? Is it poisonous? 62521 USA Illinois
4
votes
4answers
278 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
1answer
535 views

Alternative protocol for evaluating RNA integrity, using a bleach gel

I hate having to run MOPS PFA agarose gels with DEPC and everything just to verify my RNA integrity. I came across an alternative protocol that uses ordinary household bleach in the gel to inhibit ...
7
votes
0answers
312 views

What is this fuzzy, black fungus that grew on my plates in the 4⁰C room? [closed]

I often find the fungus below growing on my (ostensibly) sterile plates in the 4⁰C room. Presumably it takes a few days to reach this size. The colony looks puffy and dimpled in the middle, like a ...
3
votes
2answers
169 views

Identification of this insect

These insects lived inside the wood of my bed in little round holes. They bite, lеаving very itchy red marks. And when crushed stink really bad. In the picture the lines are notebook lines for size ...
1
vote
2answers
77 views

Does chromosomal crossover result in a mutation?

Is chromosomal crossover considered a mutation? Would this be a large-scale mutation?
4
votes
1answer
261 views

Do the eyes play any role in producing the visual experiences you have during dreaming?

Sometimes, you remember a vivid picture of a dream that you saw. What is the role of your eye in this experience? Please provide me with the answer that is as simple as possible since I am in Class ...
2
votes
1answer
53 views

Is epilepsy more heritable from maternal side?

I am thinking if paternal or maternal genetic line is the risk factor. Mitochondrial DNA is coming from maternal line. I do not know the pathogenesis of epilepsy so well that I could answer my ...
3
votes
2answers
128 views

Immunodominant Peptide

Can someone please explain me the concept of Immunodominant peptide in simple language?? I did read the wiki article but did not understand it clearly. Please help! (I have not studied biology since ...
2
votes
1answer
96 views

Has it been confirmed yet that the DNA found in dinosaurs was really DNA?

I hear different sources claiming different things, bbc said they did, wikipedia says it hasn't which is it?
8
votes
2answers
2k views

Why do rabbits often have white hindquarters?

There are several species of herbivores that have a very visible white hindquarters: several kinds of deer, rabbits, antelopes, etc. Does the white fur serve a functional purpose, or is it purely ...
2
votes
1answer
97 views

How long does it take for a hard clam (Mercenaria mercenaria) to reach sexual maturity?

How long does it take for a wild hard clam (Mercenaria mercenaria) to reach an age where they are reproductive? How does fecundity depend on age and size? I've looked at several hard clam life cycles ...
2
votes
1answer
429 views

What causes skewed ladder bands on an agarose gel?

I frequently ran into an issue where the bands of my ladder become skewed. What causes this? Here's an example: 0.7% agarose gel, 100V, 60 minutes. Same problem occurs with 1%. I loaded 10 ul of a 20 ...
2
votes
1answer
165 views

Heterozygosity and the Wright-Fisher model

I was reading the textbook Probability Models for DNA Sequence Evolution by Durrett. In chapter 1, he discusses the Wright Fisher model and the coalescent theory ...
2
votes
1answer
169 views

Is plastic just as good for you as corn?

To specify, I mean plain corn-on-the-cob, not anything processed like corn flakes. Since one of the main important functions of corn is that it's not digestible, and therefore helps with digestion by ...
5
votes
1answer
329 views

Is greed an evolved trait?

I am not a biologist, but I am fascinated by evolution. I was watching the news this morning and, as so often is the case, there was a news story about a corrupt politician who was accepting ...
5
votes
3answers
386 views

If someone were to die on the moon, would their body decay?

I heard that the footprints of Neil Armstrong are still there, so I was wondering if someone were to die there, would they remain preserved, too? If not how long would it take for them to decay?
1
vote
1answer
43 views

Localization of B and T cell

What does localization of B-Cell mean?? "Localization of B and T cell in allergens may not coincide". What does this statement mean? (I have not studied biology since last 8 years and now I am going ...
1
vote
1answer
192 views

What is the expected effect of pH on the activity of a fungal pectinase?

I am working on an enzyme assay for a fungal pectinase.I assayed the enzyme in different buffers from pH 1-12.5 However,the enzyme has good activities starting from pH1-10.5. Is it possible to have ...
1
vote
1answer
111 views

How do tight junctions in stratified squamous epithelia affect nutrient supply?

In histology we know that epithelium tissue isn't vascularized so it takes the nutrition from Lamina propia (CT) via diffusion and in other hand we know all epithilial cells have tight junction which ...
2
votes
2answers
160 views

Where to find the corrected BLOSUM matrices?

I was looking at this paper which talks about the miscalculations in the BLOSUM matrices and how the "wrong" BLOSUM62 matrix performs better than the corrected version. I was trying to find the ...
4
votes
3answers
60 views

How many Type II restrictions enzymes are currently available (commercially) [closed]

How many Type II restrictions enzymes are currently available (commercially) for purchase as of the date of this posting (September 1, 2014)
1
vote
1answer
59 views

Applying Constraint Programming to sequence alignment/analysis

My Masters program is focused on formal methods such as SAT solving and constraint programming. I am interested in applying such techniques to problems in sequence alignment and sequence analysis, ...
3
votes
0answers
60 views

Synthesis of Fatty Acids Longer than 16 Carbons

I understand that the human body when performing Fatty Acid Synthesis can synthesize only until C16 (palmitate). However the ER has desaturases and elongases. I know that desaturases are used to add ...
1
vote
1answer
126 views

Are retroviruses cytotoxic?

There are typically hundreds of retroviruses found in healthy human beings. Are retroviruses then cytotoxic? (In other words, are they able to kill or damage other cells).
2
votes
1answer
273 views

It is possible for person with AIDS be negative for HIV antibodies?

I'm just curious as there was a bit controversy around this topic. It is possible for person with AIDS be negative for HIV antibodies? As of 1989, the CDC reported that 5% of all U.S. AIDS patients ...

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