1
vote
1answer
104 views

Genetics independent assortment?

As indicated in this question, what do you think is is the best explanation for the observed progeny, is it because distance between genes affects recombination frequency? My main concern is ...
2
votes
1answer
69 views

What is the creature with the lowest neuron count that demonstrates cognition beyond reflexes?

I'm under the impression that nematode worms just perform the same scripted actions over and over again in response to specific stimuli. They have 302 neurons. Chimpanzees display problem solving ...
1
vote
1answer
53 views

how cells make other macro molecules?

We know that the nucleus of the cell is the White House of the cell and its DNA is the president and it commands to make protein. So my question when DNA only codes for protein and enzymes,after the ...
1
vote
1answer
75 views

What cell types produce immunoglobins and where are those cells found?

I know B cells found in bone marrow produce immunoglobin G. But IgM is produced in mucosal cells at least in the gut. Can you find immunoglobin expressing cells in other tissues in the human body? ...
5
votes
2answers
2k views

How do we know that everybody's DNA fingerprint is unique?

How do we know that everybody's DNA fingerprint is unique? I know, I know, everybody's DNA is unique. But when we do DNA fingerprinting, we're looking at very specific regions of high variability. ...
0
votes
3answers
627 views

Why do we exhale after we hold our breath?

I tested this out with my friends, and I find that after they hold their breath and can't hold it anymore, they exhale air, instead of inhaling air. Interestingly, they all try to inhale in as much ...
1
vote
1answer
309 views

What's the difference between an embryo and a fetus?

The most I've been able to come up with is that fetuses are embryos slightly farther along in their development. Is that correct? Thanks! evamvid
4
votes
1answer
83 views

Ribosomal RNA amount in a Drosophila cell

I am isolation RNA from Drosophila larvae brain with TRIzol method. What percentage of extracted RNA will be ribosomal RNA? I am only interested in mRNA, so I am trying to figure out whether I need to ...
5
votes
2answers
89 views

Improving myopia

I have a friend who no longer needs glasses. He previously had myopia in both eyes but over the years it has improved until he no longer needs glasses clinically. He's had glasses for over 30 years ...
8
votes
1answer
177 views

Genetic Drift: Models, assumptions and empirical observations

There two main mathematical models to describe the process of genetic drift are Moran model and Wright-Fisher model. My questions concern the assumptions of these models, the existence of other ...
0
votes
1answer
204 views

Can too low oncotic pressure lead to Third spacing and Edema?

I know that low oncotic pressure is associated with many pathologies. I am interested how it is associated with Third spacing. My professor says that it can permit edema formation. The opposing ...
0
votes
1answer
15 views

Pathogenesis of Group B Streptococci and C5a

I am thinking the pathogenesis of the C5a in GBS. I think the pathogenesis happens like C5a-peptidase in acid environment (Sialic acid, capsule) $\to$ cleaves C'-derived Neu chemoattractant C5a ...
0
votes
1answer
58 views

What is immunosuppression? Why would one use it? [closed]

What is immunosuppression? I know it is used in cancer patients, but why would one want to suppress the immune system? Do homeopathic physicians ever use immunosuppression, or do only allopathic ...
-1
votes
2answers
274 views

Are the 8 principal sugars in glycoproteins “essential sugars”? [closed]

Are there "essential sugars"? Some have suggested that the 8 principal sugars found in glycoproteins are "essential sugars": Galactose Glucose Mannose N-Acetylneuraminic acid Fucose ...
7
votes
1answer
134 views

Does the MS2 RNA binding protein have any translational repression effects?

Reposted from Quora: http://www.quora.com/Does-the-MS2-RNA-binding-protein-have-any-translational-repression-effects I'm thinking of the MS2 protein binding to its RNA hairpin target. Would the ...
4
votes
1answer
30 views

What are the effect of microtubule or microfilament inhibition on yeast expression profile?

I was wondering whether anyone has looked at what are the expression changes in yeast when the microtubule or the microfilament polymerization is inhibited? Have there been whole-genome studies?
6
votes
1answer
186 views

How do scientists create specific mutations?

Suppose I want to create a mutant like Antennapaedia how will I go about accomplishing it ? I know that radiation and certain chemicals are mutagenic. So do scientists subject animals to such ...
0
votes
1answer
121 views

Gene pool simulation [closed]

this simulation, you sampled the gene pool without replaceing beads in the beakerafter you drew each one. Thus, f(A) and f(a) in the gene pool changed slightly after each bead was drawn. For example, ...
2
votes
2answers
99 views

Is there any evidence of increased life expectancy for animal species?

Life expectancy for human has significantly increased during the last century or so. We all know that there are many reasons that are not linked with "evolution", but I am wondering if such change in ...
1
vote
1answer
74 views

How to parse SCOP parseable files PDB residue identifiers?

I am trying to parse the SCOP parseable files, specifically dir.des.scop.txt ver 1.75. But, I have been facing problems with the PDB residue identifiers in the file. This is a tab limited file and the ...
3
votes
1answer
207 views

Benefits of CLARITY?

What are the benefits of CLARITY over this technique that was published more than a year earlier? Of course the second technique needs a fancier microscope that is likely more expensive and requires ...
1
vote
1answer
48 views

Is there a scientific name for the field of study focusing on the hemispheres of the brain and their control of opposite sides of the body?

I'm assuming this field of study would focus on motor controls, movement, and exercise, but it could also focus on activities which strengthen the corpus callosum or stimulate a specific half of the ...
3
votes
0answers
211 views

Do Asian women have more difficult births than Europeans?

I recently heard a claim that Asians in general have more difficult births than Europeans. Is this true? I have found a few studies(1,2) on the effect of ethnicity on birth outcomes but they seem to ...
3
votes
1answer
37 views

What is the genetic distance where linkage can be ignored?

I heard several times that two SNPs, that have at least 1'000 nucleotides between them, can be seen as 'unlinked' due to frequent recombination events. I also once saw a paper showing a graph "degree ...
-1
votes
2answers
113 views

PAH gene mutation

Analysis of the DNA of the Phenylalanine hydroxylase (PAH) gene in a patient with phenylketonuria revealed a mutation in the protein coding region whose predicted effect would be to replace the amino ...
2
votes
2answers
1k views

Explanation of the terms “downstream signaling” and “upstream signaling”

In molecular biology, what's the meaning of the terms "downstream signaling" and "upstream signaling"? What's the difference between them?
1
vote
1answer
33 views

What are the best detection medias for cholera?

I heard this fact that you can use some [hypertriade] for vibrio cholera diagnosis which has compontents sucrose (yellow) mannose (yellow) arabinose (do not ferment; stay dark pink) I did not find ...
0
votes
1answer
17 views

Has H.pylori paracellular activity?

I know that it has transcellular activity i.e. it can pass through neighbouring cells. However, I am not completely sure if it does not have paracellular activity, see this: H. pylori did not ...
0
votes
1answer
48 views

RNase and EtOH issue

I work with RNA and I have some RNase issues. For example I am using RNeasy mini kit and at one step I use 100% EtOH. It does not say it is RNase free or not. Does absolute EtOH inhibits or removes ...
0
votes
2answers
61 views

Why is succinate dehydrogenase attached to the inner mitochondrial membrane?

Succinate dehydrogenase is attached to the inner mitochondrial membrane.All the other enzymes of the Krebs cycle are located in the matrix of mitochondria. What is the biochemical reason behind ...
0
votes
1answer
76 views

calculate the number of heterozygotes [closed]

The ability to taste PTC is due to a single dominant allele "T". You sampled 215 evolution students, and determined that 150 could detect the bitter taste of PTC and 65 could not. Assuming this trait ...
3
votes
2answers
84 views

Why do humans circulate monosaccharides instead of disaccharides as in plants?

Plants transport food mostly in the form of disaccharides like sucrose but humans transport them in the form of a monosaccharide - glucose. What is the reason behind this ?
1
vote
0answers
194 views

Microtiter Dish Biofilm Formation Assay- Pseudomonas and Crystal Violet

If Pseudomonas is a gram negative bacteria, it does not retain crystal violet but why is it that so many people are using crystal violet staining in theri Microtiter Dish Biofilm Formation Assay?
-1
votes
1answer
221 views

What is the benefit of using Gonoline-Euroline in combination? [closed]

I was heard that this combination first Gonoline and other culture another culture on Euroline is good one. What is the benefit of using Gonoline-Euroline in combination?
0
votes
2answers
88 views

What is the right spelling for this agar? [closed]

I could not spell the agar [gonoline-uroline] which I heard yesterday. My spelling is so wrong that I could not find it in Google. What is the right spelling for this agar?
0
votes
1answer
38 views

Why do doctors do chemo or transplantation for cancers that don't respond well to these treatments? [closed]

From the UpToDate article on multiple myeloma: In most people, chemotherapy partially controls multiple myeloma; rarely, chemotherapy leads to complete remission. Also: Transplantation, ...
12
votes
2answers
209 views

Why do most breast cancers occur in women?

According to Korde et al. (2010): Male breast cancer accounts for less than 1% of all cancers in men and less than 1% of breast cancers. This raises the question: Why do most breast cancers ...
1
vote
2answers
68 views

Can viruses be used to extract oil from algae?

I read that one hard step in algae oil extraction is to rupture (or fracture) the cell walls to get the contents inside. Some people use chemical methods; some use sonication or mechanical forces. I ...
2
votes
1answer
49 views

GULO only for mammals?

I am not a biology student, but just want to know if GULO gene are present only in mammals or all species possess it ? And is GULO gene active in human fetus?
0
votes
1answer
45 views

Shigella's O antigen (PAI synthesised) and passage through host defences

The O antigen is synthesised by Pathology islands (PAI). O antigen may be a factor why Shigella survives the passage through host defences. I am interested in which step of pathogenesis. There are ...
0
votes
0answers
37 views

Can we define biological age? [duplicate]

How can we define ageing from a biological standpoint without making an appeal to chronological age? Related, but less important, are there any metrics we can use to determine someone's biological ...
5
votes
3answers
180 views

What are some examples of genes that code for multiple proteins?

The title pretty much says it all. It is widely taught that a gene in a eukaryotic system could produce more than one protein due to post-transcriptional modification, but I do not believe I have come ...
5
votes
2answers
676 views

Why does squinting allow you to see objects more clearly?

How does squinting alllow one to see clearer pictures? What are the harmful effects?
1
vote
1answer
35 views

What indices can we use to describe fitness landscapes?

We usually talk of smooth or rugged fitness landscape. Are there any (standard) indices to measure the "structure" of fitness landscapes? For example, one might consider the mean epistatic ...
2
votes
1answer
2k views

Isopropanol precipitation of DNA - duration and magnitude of cold storage

DNA prep protocols often include a final precipitation step with alcohol, often isopropanol, where the DNA must be kept in the alcohol, at a low temperature such as -20C or -70C, often overnight. ...
5
votes
2answers
343 views

Why is Portuguese man o' war considered a colony?

The wikipedia entry on the Portuguese man o' war says: ... the Portuguese man o' war is ... not actually a single multicellular organism but a colonial organism made up of many highly specialized ...
0
votes
3answers
92 views

Phylogenetic tree

I want to find the conventional phylogenetic tree of human, mouse, C elegans and drosophila, without all the other organisms. Do you know where can I get it? thanks, Noga
1
vote
1answer
240 views

question about directional selection

Cattle breeders have improved the quality of meat over the years by which process? A) artificial selection B) directional selection C) stabilizing selection D) A and B E) A and C I know the answer is ...
0
votes
1answer
77 views

M-type potassium channels by muscarinic receptors

How does the closure of M-type potassium channels by muscarinic receptors result in increased excitation of the target neuron?
0
votes
2answers
144 views

Systemic sensory confusion?

Sometimes when a person gets touched on one part of the body they feel it else where and may think it came from a different part of the body. What causes this? Other examples are similar to why you ...

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