1
vote
3answers
73 views

What fraction of sites are expected to be polymorphic?

Question Consider a very long (eventually infinite) DNA sequence of neutral sites. Consider a panmictic population of constant size $N$ with a per site mutation rate of $\mu$ where all individuals ...
2
votes
2answers
12k views

What are the functions and differences between axons and dendrites?

My textbook doesn't do a very good job of pointing out what the differences between the two are. It basically mentions axons only in the same breath as the synapse (that synapses are the endings/tips ...
5
votes
1answer
326 views

What flowering green plant is this?

I got this green plant as a gift many years ago, but I have never seen it flower before. It has a strong, pleasant scent and cool flowers so I'd really would like to know what it is.
-1
votes
0answers
59 views

How to eliminate prairie dog colonies from a field? [duplicate]

I have several fields infested by gunnison prairie dogs. These things cause damage to the fields, irrigation system, livestock, and spread disease. For years, I've invited neighbors/friends to come ...
0
votes
0answers
16 views

Are there any non-harmful viruses that can alter a specific mutation?

Are there any non-harmful viruses that in going into a cell and using the cells 'machinery' and genetics to 'copy' itself actually changes some of the cells genome , maybe altering some mutations? ...
8
votes
3answers
6k views

What is the distinction between chemokines, cytokines, interferons and interleukins?

They all seem to describe molecules of similar function and many people seem to use them interchangeably. Also please include any other similar molecules if I've forgotten any in the list above.
9
votes
1answer
343 views

How do female hormones cause blood to clot?

On most female-hormone supplements you get a warning that is something like this: The use of a combination hormonal contraceptives (CHC), like NuvaRing, is associated with increased risks of ...
4
votes
1answer
57 views

What is the fluid clearance rate inside the retina?

I'm attempting to model the chemical concentration between several compartments of the eye, including the retina. Does anyone have any idea what the rate of fluid removal is in the retina, or could ...
2
votes
0answers
51 views

Do domesticated animals necessarily live longer than wild animals? counterexample wanted!

Generally domesticated animals do not need to worry about their food and other predators. They have a lower probability to get sick. However, it seems there is no sharp difference between wild pigs ...
6
votes
2answers
7k views

Does mixing alcoholic drinks really make you more drunk?

There is plenty of anecdotal evidence ("beer after wine and you'll feel fine, wine after beer will make you feel queer") that mixing alcoholic drink types leads to a stronger effect, but I can't find ...
5
votes
1answer
61 views

Is transplantation of neurons between species possible?

Can brain tissue from one species be implanted into the brain of another species? Because the brain is tolerant to the introduction of antigens (it is said to be immuno-privileged), I was wondering ...
8
votes
2answers
863 views

Do males of all sexual species have Y chromosomes?

I know for instance some cells are sexual, so, this got me wondering, do the males of all species that have distinct sexes have Y chromosomes?
5
votes
1answer
21 views

How to calculate the percentage of heterozygous cells based on a gene map

I've encountered the following question and am quite stumped by it. A female with genotype AABBCC has been hybridized with a male that has the genotype aabbcc. The first generation (F1) has been ...
2
votes
2answers
32 views

Osmotic Pressure and Enzyme Activity

Is it true that in an enzyme-catalyzed reaction, the rate of reaction does not vary with varying osmotic pressure? Instead of just a true or false answer, why does it, or why does it not vary with ...
1
vote
1answer
13 views

Correct enzyme nomenclature

I notice many wikipedia articles, courses, pathway sites use a different abbreviation for the same enzyme. Eg: Wikipedia lists the abbreviation of phosphoglycerate mutase as PGM, whilst wikipaths ...
7
votes
1answer
49 views

How does chromosome fusion get fixed in the population?

It's well known that one of human chromosomes is the result of fusion between two chromosomes in a primate ancestor. If we put anthropocentrism aside, it becomes clear that fusion events happened a ...
4
votes
2answers
86 views

Do variant callers miss rare variants in reference?

Generally variant calling programs (such as GATK-UnifiedGenotyper) look for differences between reference genome and submitted sequence. However, we all know that reference genome consist rare ...
3
votes
1answer
60 views

How many traits can a multivariate breeders equation handle?

The multivariate breeders equation (MBE) by Lande predicts the change in a trait $\Delta \bar z$ (response) as $\Delta \bar z = G \beta$ where $G$ is a genetic variance-covariance matrix and ...
0
votes
0answers
34 views

Saline solution for animals

A popular "well-known fact" is that all creatures on Earth consist mostly of water (i.e. H2O). Indeed, a liquid called "normal saline solution" is just a solution of 0.9% sodium chloride in distilled ...
0
votes
1answer
23 views

How does the MET gene work and what happens when the promoter region gets mutated?

I am doing research on inherited risk of Autism Spectrum Disorders(ASD) due to common Copy Number Variants(CNVs) One of the mutations is the 'CC' variant of Rs1858830 in the promoter region of the MET ...
4
votes
1answer
47 views

How does botulinum toxin enter the blood stream from the digestive tract?

To my understanding, large polypeptides such as botulinum toxin cannot pass the intestinal lining intact. How, then, can it enter the bloodstream and cause botulism poisoning?
4
votes
1answer
71 views

Do bees make honey from fallen fruit?

I know bees make honey from nectar, and I know they drink the juice of fallen fruit, but do they actually make honey from fruit, or do they only eat from it for themselves?
3
votes
0answers
26 views

How long does it take unused antibodies to clear the system?

Say you have the flu and a normal immune system. Now you're all better but your antibody level is still elevated. How long does it take for those antibody levels to go back to a base value?
10
votes
3answers
234 views

Why are the organs for reproduction and urinary excretion combined?

We eat food for getting energy to our body parts, and we excrete the wastes through urine, feces, and perspiration. Why has nature combined the urinary tract with the genital system (urogenital ...
2
votes
1answer
30 views

Why are our bodies created to itch when histamine is released by our immune systems?

Why do bug bites and cuts itch when scratching them clearly doesn't help us survive? Did our early ancestors need to rely on this itching sensation, or is it just that the receptors for itches just ...
2
votes
0answers
24 views

How large might a paper wasp nest become?

About two weeks ago I noticed a new wasp nest in my back yard. I generally leave them as long as they aren't interfering with anything, but this nest has suddenly grown quite large and they are ...
5
votes
2answers
41 views

Why do epithelial cells arrest in response to serum?

Primary epithelial cells, for example human mammary epithelium, fail to proliferate (arrest) in serum-containing medium. Therefore, a common growth medium for epithelium contains pituitary extract ...
1
vote
1answer
16 views

Generate full dimer from monomer with C2 symmetry?

I downloaded a PDB file of a dimer, but it only contains the monomer, and it says that the dimer can be obtained from C2 symmetry. For an example see here: ...
4
votes
1answer
138 views

What do “e” “-” “C” and “E” mean in this output?

I have given an input of this protein sequence: MEPVDPRLEPWKHPGSQPKTACTTCYCKKCCFHCQVCFTTKALGISYGRKKRRQRRRPPQGSQTHQVSLSKQPTSQPRGDPTGPKE from this website along ...
2
votes
1answer
32 views

Change Genbank entry date with Biopython

I can create a new Genbank record in Biopython with the following code: ...
5
votes
2answers
159 views

Do animals exist which have great vision, but see only grayscale?

In computer vision the color information is often discarded, as most object recognition tasks seem to work just as well on the greyscale image (even better, because there is less unnecessary ...
-3
votes
1answer
77 views

If I buy a banana at the market, is there any chance that an insect is hiding inside it? [closed]

I watched this horrifying video on Youtube. It shows movement beneath the skin of a banana and then a spider pushes it's way out. Suffice to say I'm too scared to eat bananas anymore! I would like ...
4
votes
1answer
38 views

Why lab technicians use indirect (antibody reaction) method for diagnosing?

In microbiology we have two types of microbial diagnosis. The direct method is where we detect the invader's DNA, Antigens or culture to see the exact pathogen while the second, indirect, method is ...
4
votes
2answers
474 views

Is it true that bees and wasps don't sting if struck by hand while they are in flight?

Is it true that wasps don't sting if struck by hand while flying? I know of one person who claims to have done this at least 20 times and has never been stung. And out of curiosity (not that I'd want ...
18
votes
5answers
3k views

If a trait would be advantageous to an organism, why hasn't it evolved?

If a trait would be advantageous to an organism then why hasn't it evolved yet? Conversely, if a trait is not advantageous or mildly disadvantageous, why does it exist? In other words why does ...
4
votes
2answers
87 views

Does learning increase the number of neurons in the brain?

I am attempting to understand neurogenesis related to learning. Does learning increase the number of neurons in the human brain? What would be some good scientific publications to read?
6
votes
1answer
69 views

Why do skinny people live for shorter than the norm even though calorie restriction extends life expectancy?

If I understand correctly, calorie restriction may extend life expectancy slightly (not proven exactly how much for human). But according to the statistics, skinny healthy people have even shorter ...
10
votes
1answer
66 views

Can a lizard shed a regrown tail again?

Some lizards are famous for their ability to voluntarily shed their tail to elude predators (Autotomy). After a while, the tail will be regenerated, though with slightly different qualities, as ...
2
votes
1answer
33 views

Why is there a compound highlighted in red in a KEGG Module search?

Considering the following module: http://www.kegg.jp/kegg-bin/show_module?M00115+C00003 why is the compound C00003 marked in red?
0
votes
1answer
25 views

Presence of reaction module in bacteria but not in Eukaryotas (human)

From the statistics page, I found that the Module-M00008 is present only in bacteria and not Eukaryotes. Why so? I noticed that all the compounds necessary or the reaction are present in human body ...
1
vote
1answer
37 views

shRNA knockdown not showing with Western

I've recently been performing shRNA transfections and was hoping to get some advice on why I'm not seeing any knockdown via western blot I transfected by MDAMB468 breast cancer cell lines with shRNA ...
1
vote
1answer
31 views

Can roots have cuticle, especially aerial roots?

In my school biology book, it is written that cuticle covers the epidermal cells in aerial parts of plants and root epidermis doesn't have cuticle. My question is that whether aerial roots, in plants ...
3
votes
2answers
32 views

Cell line immortalisation biosafety

Cell lines are often immortalised by artificial expression of proteins which specifically cause the knockout of important cancer suppression genes or the activation of proto-oncogenes. Cellular ...
6
votes
2answers
46 views

Can a woman possessing 1 mutated allele show attenuated color-vision deficiency?

Women possess two X chromosomes. However, during development, when the embryo has about 32 - 64 cells, one of these chromosomes is randomly inactivated (in each cell) by an lncRNA named Xist. As a ...
3
votes
1answer
50 views

Color vision across species

Is it true that color vision is sex-linked for all species with binary sexes? Is there an evolutionary significance to the fact that color vision is X-linked in humans? E.g., only female humans can be ...
1
vote
1answer
13 views

What information does the KEGG Module statistics page show?

While browsing through the home page of KEGG Module, I clicked the button named Module statistics. Can someone tell me what does these numbers signify? What are they the statistics of?
1
vote
2answers
41 views

Difference between modules in KEGG Module

The KEGG module M00115 includes a set of reactions while M00542 does not have any; it just shows the list of enzymes. Is the reaction set for M00542 still unknown?
2
votes
2answers
58 views

Does “squinting” make you concentrate better on a logic test?

We have all had those moments of intense concentration on some tough exam, perhaps a college test or whatever... Why is it that when we squint, it feels like we can focus and concentrate better on ...
2
votes
1answer
1k views

Is it possible to still grow taller after growth plates have been closed?

In addition, when do we know we stop growing taller? Or we keep growing taller? To the first question: Recently, I went to a doctor to have a check up, he said that my growth plates are closed and ...
5
votes
1answer
238 views

Why did Opabinia have 5 eyes?

I recently read about a fossil called Opabinia. What intrigues me is that it had five eyes. I was under the impression that most features, such as eyes, ears and legs are always even-numbered, i.e., ...

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