7
votes
1answer
322 views

What evolutionary advantages are provided by ovoviviparity?

I read that some sharks are ovoviviparous. What advantages and disadvantages are provided by this type of reproduction as opposed to egg laying and live birth?
8
votes
2answers
65 views

All UniprotIDs of a cancer pathway

I need to download all uniprotIDs of a cancer pathway, say the AKT Signaling. It may be super easy, but I don't know which resource to look at since it is a new field. How/where do I find these?
6
votes
3answers
376 views

Why are the fertility rates of large predators kept low?

Predators at the top of a food chain, like lions, seem to have a relatively low fertility rate, which fits well to the ecosystem and avoids overpredation. But what is the mechanism that keeps the ...
-3
votes
1answer
107 views

Human Species of Males/Females [closed]

Why is it that when there is discussion about Race/Subspecies it is never about the genetic/physical differences between males and females. So every argument has been about physical and geographic ...
5
votes
1answer
129 views

How do biologists infer correct ORF of a DNA sequence?

Each DNA (RNA) sequence has 6 possible Open Reading Frames(ORF). My question is: What are the theoretical bases of in vitro or in silico tries to find correct reading frame of a sequence? Is it just ...
4
votes
1answer
189 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 ...
9
votes
1answer
4k views

What senses are active while sleeping?

During sleep, our body activity decreases. I am wondering on the extent of the lowering of this activity regarding our five senses. Clearly, the sense of touch is still very efficient since shaking a ...
3
votes
1answer
143 views

How do cats survive falling from great heights?

Among mammals, cats are able to land safely when falling from great heights. For example, when compared to dogs or humans they can survive drops from relative large heights. How do they manage? A ...
3
votes
0answers
82 views

Is there a standard formula/calculation for sexual dimorphism?

Is there a standard, or most accepted, way to present a value for sexual dimorphism? For example, one could use $$\frac{\text{Female value}}{\text{Male value}} -1$$ This would give negative values ...
3
votes
1answer
81 views

How does beta branching stop alpha helices from forming?

I am told that beta branching interferes with alpha helix formation. Problem is that I don't see how beta branching has anything to do with alpha-helix formation. Beta-branches are on the outside of ...
1
vote
0answers
147 views

First documented beneficial mutation?

I've been reading up on beneficial mutations, and am curious when we discovered and documented the first one. Can anyone point me to the first documented beneficial mutation? Per request, let me ...
3
votes
0answers
50 views

How to get a pdb file of a single atom?

I am trying to get a pdb file that contains a single atom, it doesn't matter if it's Hydrogen or another atom. How can I obtain this? Are there any pdb files with just a single atom available to ...
1
vote
1answer
66 views

Was Earth's atmosphere more buoyant in the prehistoric era then today?

The mass and size of the dinosaurs and prehistoric insects continues to amaze me. I read from an earlier post that oxygen was more abundant during the prehistoric era. However supporting the weight ...
3
votes
2answers
371 views

How to set threshold in ImageJ for quantifying relative fluorescence?

I have taken images from two different samples that have uptaken EdU during DNA synthesis (S-phase). The experiment setup is to find which condition had uptaken more EdU. Therefore I am detecting EdU ...
5
votes
1answer
1k views

Why do we get 'bags under our eyes'?

Why do these circles form around the eyes if somebody is tired? And why does fatigue express itself around the eyes this way? Can I get eye bags very quickly in another way? http://www....
1
vote
1answer
64 views

How can I isolate live Wolbachia endosymbionts from Drosophila [closed]

I am interested to culture Wolbachia bacteria in cell line.
3
votes
2answers
5k views

Blood circulation - How to expand blood capillaries?

Do blood capillaries expand? If yes, through what means can it be done? And can warm water also be used to expand blood capillaries?
9
votes
1answer
999 views

How are we able to find the specific sites at which DNA binding proteins bind?

We know that some DNA binding proteins are site specific, that is they recognise and bind to a specific nucleotide sequence. My question is how can we precisely tell at which sites they bind? Is it ...
8
votes
2answers
192 views

How to name such grouping behaviour?

Under which keyword would you try to find out more about the grouping behaviour which looks like this? Does anybody recognizes such behaviour, or know an animal species which uses it? My tries: ...
3
votes
1answer
170 views

What fish (and/or shellfish) species with a multi-year life-cycle, besides salmon, die after spawning?

Most species of salmon die after spawning. Are there any other types of fish that spawn once and then die after a multi-year life-cylce? Is this a rare life history strategy among our human exploited ...
12
votes
4answers
282 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. ...
14
votes
2answers
2k views

Why I have to pee more often in low temperature? [closed]

I realised that I have to pee more often in winter or simply the temperature is low. Is there any scientific explanation, or just simply psychology?
4
votes
1answer
44 views

How to measure heat loss in Tardigrades

I want to measure metabolism in tardigrades (a jar of 30 tardigrades). I know that an easy way to measure metabolism is heat loss; I can just measure the temperature of the water before and after a ...
0
votes
1answer
47 views

Can memory be improved with mental training? [closed]

I am a man in his mid thirties, but I already have a pretty bad memory. (I have always had a bad memory.) I can remember certain kinds of facts and music very well, but when it comes to words or even ...
1
vote
0answers
56 views

Do Parasaurolophus have hands with fingers to grab?

http://en.wikipedia.org/wiki/Parasaurolophus#mediaviewer/File:Parasaurolophus_cyrtocristatus.jpg I cannot tell if the hands have fingers strung together to form a hove, or fingers to grab. I have ...
8
votes
1answer
161 views

Up to date, extensive documentary about dinosaurs?

I just finished reading the Wikipedia page about dinosaurs, and I very much enjoyed it. I knew that much of what I learned in the 80's as a child is (and was) incorrect, and now that I am a parent, I ...
1
vote
1answer
78 views

Alternative plant taxonomies to Linneaus

In addition to Linneaus-inspired taxonomies of the botanical world, I suppose there are some other proposals for different kinds of taxonomic accounts, perhaps for specific sub-domains of botany or ...
3
votes
1answer
164 views

Are abrasions considered closed wounds?

A closed wound is one where skin is intact and underlying tissue is not exposed to the environment. Abrasion is an erosion of skin usually due to sheering force. In most cases the dermis is intact ...
3
votes
1answer
76 views

How does Trifluralin kill newly germinating seeds, with almost no effects on established ones?

Trifluralin (2,6-Dinitro-N,N-dipropyl-4-(trifluoromethyl)aniline) is a pre-emergent herbicide used in landscape beds before the application of mulch (my use for it, anyway). It kills the weeds as they ...
0
votes
0answers
28 views

Polychromatic Fur considered against Monochromatic Hair

As I was gazing at a strand of fur that had shed from my cat, I was struck by the alternating bands of white, black, and tan. It seems that genetically coding for such an intricate coat pattern would ...
3
votes
1answer
96 views

Heart Rate being normal when under treatment for the bends

When you surface from diving too quickly; you get "bends" - these are caused by gas bubbles forming in your lungs (especially nitrogen). This causes breathing problems if not treated since the bubbles ...
3
votes
1answer
81 views

List of dinosaurs synonyms

Is there a comprehensive list of dinosaurs synonyms with indications of which name is now considered correct? Something like "there's no brontosaurus, there's only Apatosaurus", "there's no Anatotitan,...
2
votes
1answer
35 views

How does Isoxaben kill newly germinating seeds, with almost no effects on established ones?

Isoxaben (N-[3-(1-ethyl-1-methylpropyl)-1,2-oxazol-5-yl]-2,6-dimethoxybenzamide) is a pre-emergent herbicide used in landscape beds before the application of mulch (my use for it, anyway). It kills ...
3
votes
1answer
772 views

Why are sperm cells not attacked by the female immune system? [duplicate]

Whenever a foreign particle enters into someone's body, it is attacked by the white blood cells. I just want how it is that, when sperms enter the female body, they are not attacked by the the woman's ...
6
votes
2answers
713 views

Why sperm count matter for pregnancy?

In order for a woman to become pregnant, sperm is needed. Why is sperm count so important for pregnancy? http://en.wikipedia.org/wiki/Sperm
2
votes
1answer
793 views

Thermodynamics of Forming Peptide Bonds

Which of the following shows the correct changes in thermodynamic properties for a chemical reaction in which amino acids are linked to form a protein? A) +ΔH, +ΔS, +ΔG B) +ΔH, -ΔS, -ΔG C) +...
1
vote
0answers
194 views

Why not use lactase to aid the break down of lactose when making biofuels?

I did an experiment using nine different substrates (Lactose + lactase, corn, sugar cane, glucose control, wood, grass, no yeast control and yeast control) and observed their fermentation rates. ...
6
votes
2answers
78 views

SNPs and locations

I am new to reading raw DNA. When comparing two people's raw data, why does one person have a different SNP than the other, at the same location, on specific chromosome? But on a different chromosome ...
1
vote
0answers
59 views

Cannot conjugate Biotin-labeled DNA to Streptavidin-labeled solid surface

I have been trying to immobilize DNA by the bioconjugation of biotin and streptavidin, but I cannot get this work. I added EDC and streptavidin to COOH ...
27
votes
7answers
6k views

Is there anything that is completely non-toxic to humans at any dose?

Lately I have seen a number of unrelated "scientific" debates over whether certain substances should be outlawed because they are toxic to humans. My initial, informal reaction is usually to respond ...
5
votes
1answer
260 views

Plasmid in the nucleus and gene expression

If we insert a plasmid into a human nucleus that contains exact copy of gene and all relevant promoters to produce some human protein, will the cell create functional protein from that plasmid only ...
8
votes
2answers
2k views

Why don't breast enlargements leave any marks of surgery on breasts?

If we get stitches, we get marks left on the skin, but there are no marks for breast enlargements. I saw a YouTube video about a breast enlargement wherein a doctor makes a cut. Where does the cut ...
10
votes
2answers
329 views

Can canines communicate with each other using gaze direction?

After researching why humans have white scleras when most primates have dark scleras, I stumbled upon the cooperative eye hypothesis. It proposed that white scleras may have evolved on behalf that it ...
4
votes
1answer
194 views

why reptiles still stimulate even after the death?

I saw a video in which a decapitated snake head still tried to bite. I also saw a video in which a man was hit by the moving tail of a dead crocodile. So why do reptiles move even after the death? ...
2
votes
1answer
93 views

Are alleles passed down and shuffled randomly to the offspring during meiosis or fertilization?

If it does occur during meiosis, are the alleles switched over from one sister chromatid to the other during the crossing over process in Prophase I?
3
votes
1answer
32 views

How long do zebra fishes remain transparent?

As larva, zebra fishes are transparent, at least up to 5-6 days. I wonder what would be the upper limit of the transparent period. This is of relevance considering purposes for imaging. The question ...
4
votes
2answers
433 views

Why White Blood Cells (WBCs) do not react to foreign bodies like sperm?

Why do the white blood cells allow foreign bodies like sperm to exist inside body cavity without any reaction? White blood cells function is to fight against foreign bodies (from the text books).
-1
votes
3answers
964 views

Why scientific names of animals & plants are made difficult to spell & remember?

Why scientific names of animals & plants are made difficult to spell & remember? Mango: it is easy to spell. Corvus splendens: it is difficult to spell
2
votes
0answers
16 views

Why there are two rounds of cytosine de-methylation in mammalian development?

I assume that the key biological meaning of cytosine de-methylation during germline development in germline progenitor cells is to reset imprinted genes and then set methylation pattern on these genes ...
2
votes
0answers
23 views

Which biosynthetic pathways take place in the plastid and were are they located?

I know that the isoprenoid, jasmonate, glucosinolate, fatty acids, chlorophyll, starch, and aromatic amino acid syntheses are located in the plastid. But I don't know if they are located in the ...

15 30 50 per page