5
votes
1answer
260 views

Variations in Genome Sizes

Why is there wide variation in genome size amongst groups of protists, insects, amphibians and plants, but less variation within groups of mammals and reptiles?
7
votes
1answer
213 views

Puffball mushroom species ID?

Found this mushroom today. It's a kind of puffball mushroom and I think pestle puffball but I hope someone can confirm that/point me to other likely species. It was in Central Eastern Sweden ...
3
votes
1answer
334 views

Are there any 6 limbed reptile fossils?

Were any 6 armed "tetrapod" fossils ever found? I've seen some lobe finned fish with two sets of shoulders in an evolutionary bio book... I'm curious because I'd like 4 limbed and 2 winged dragons to ...
2
votes
0answers
52 views

Natural selection and the Galapagos Islands [closed]

Woodpeckers found on the South American mainland are able to peck insects from the bark of trees. Would the woodpecker finch have been able to survive if woodpeckers had found their way to the ...
0
votes
1answer
56 views

Male behaviour during breeding season

The mountain blue bird build nests to attract females and exhibit aggression towards other males during breeding season. Which of the following is likely to give the birds maximal evolutionary ...
5
votes
1answer
153 views

Synthetic construct with multiple ORFs not expressing

I designed a synthetic construct on paper and got it synthesized from a company. The objective was to make a vector which can be used to study both transcriptional and post-transcriptional regulation ...
1
vote
1answer
111 views

Why would the Camargue horses have a white coat while the foal have a dark coat?

The current issue of the magazine Lonely Planet India(Oct 2013) presents a photo of Camargue Horses which are white coated and mentions that they are born with dark hair. A search shows that the foal ...
8
votes
3answers
140 views

Are there echolocating insects?

Echolocation is the ability to obtain spatial information of the surroundings from echos generated by the animal. There are bats and other vertebrates that naturally use it. I was wondering if this ...
6
votes
2answers
3k views

How do I deal with sticky and viscous samples from cell lysates?

To check a protein expression I pelleted a small amount of E. coli before and after induction and lysed them by redissolving them in SDS-PAGE loading buffer and heating them to 95 °C for 1 minute. ...
2
votes
3answers
145 views

What kind of arthropod/animal is this?

Can anyone identify this strange creature? I live in a very urban part of Montreal, Canada. It wasn't moving (seemed dead) and although the image is huge, it wasn't as big as it seems (a couple of ...
1
vote
1answer
112 views

Identification of this insect?

I noticed several of these guys outside, all in a vertical position clinging to a wall. I didn't come to them too closely, but my immediate reaction was that they are scorpions. I thought that ...
2
votes
2answers
195 views

What insect is in this photo?

Found in Russia, in the kitchen. It is about 1–2 cm length.
3
votes
0answers
354 views

Distinguishing between mitotic metaphase and metaphase II of meiosis

I'm sorry if this seems like a silly question, but I was brushing up on some cell cycle dynamics and realized that everyone was talking about the differences between metaphase I and II, and since ...
0
votes
1answer
127 views

The probability of indirect human fertilization (follow-up)

This question is a follow-up to this one. I've been wondering how small that probability is. As we all know, "safe" sex, that is (correctly) using a condom and all that, isn't perfectly safe. So, in ...
5
votes
1answer
1k views

Why do organisms excrete nitrogenous wastes?

All plants and animals excrete nitrogenous wastes in the form of urea, uric acid or ammonia. But isn't that a bit of a waste? I mean, there is a shortage of biologically available oxygen in the ...
4
votes
4answers
118 views

How to calculate extent of Sequence similarity [closed]

I had a problem that I was wondering if it could be solved by one of the techniques/algorithms used in bioinformatics to give the extent of similarity. I have a Problem Statement: we have a sensor ...
2
votes
1answer
3k views

Which blood vessel carries the most impure blood?

There is a question in my Biology textbook: "Which blood vessel in the human body carries most impure blood after few hours of meal." The answer is given as Renal artery. But I think the ...
2
votes
2answers
558 views

The antibiotic 'kanamycin' in the growing of culture E. coli

I'm a first year student and I'm not sure if I understand correctly the role played by the antibiotic 'kanamycin' in the growing of culture E. coli (Rosetta). Can anybody explain me why we use ...
3
votes
2answers
496 views

How is RNA of retrovirus converted into cDNA?

The retrovirus (oncovirus) contains RNA. It also has a molecule called reverse transcriptase. This molecule transcribes RNA into cDNA. This cDNA is the DNA copy of viral RNA genome RNA has Uracil ...
2
votes
1answer
1k views

Difference between viral and human genetic material

I have heard that there is a difference between viral and human genetic material. What is that difference? If I take my cells and take DNA out of them and insert only a small part of it having a ...
1
vote
1answer
94 views

When is wing growth in the bat complete and how soon can bats fly after wing growth is complete?

I was reading this paper by Cretekos et al (2008), in which they state that wing development in the bat is not complete until after birth - the wing continues to elongate postnatally. This would ...
-2
votes
1answer
94 views

Would I still exist if [closed]

I've been wondering for some time, but say that my mother's egg chose another sperm cell, and a baby was eventually produced. Would I still be born, but end up with different characteristics/features? ...
3
votes
1answer
80 views

Fear in elephants

It has been noted that elephants trained for war, as was done occasionally in earlier times, have still shown a tendency to panic in battle much more often when compared to a war horse trained for the ...
1
vote
1answer
103 views

Is “Fight or Flight” distance genetic

If you took a newborn animal and completely isolated it from its species, would it be capable of assuming a fight or flight distance preset by its species, due to their being no basis for what could ...
1
vote
2answers
385 views

what is knob heterochromatin?

I am reading a paper which discusses Maize Genome Structure. Descriptions of the structure is given in the papers introduction. I know about heterochromatin "heterochromatin stains intensely, ...
1
vote
1answer
135 views

Chemical structure prediction

I'd like to do chemical structure prediction using a known molecule formulas. I'm familiar with de novo protein structure prediction, but are there any programs which will go from formula to structure ...
4
votes
3answers
138 views

What makes a metal safe to use for an artificial joint?

What determines if a metal is suitable for transplantation such as in the hip? What I am most interested in however is why might some metals be toxic to animals once in the body?
2
votes
2answers
216 views

Basic text/notes on DNA structure (for non-biologists)

I am a mathematics grad student researching knot theory, and I've recently discovered that there is a connection between knot theory and DNA structure (if I understand correctly, when DNA strands ...
11
votes
1answer
2k views

Why does oxygen bind to hemoglobin in an specific angle?

There is an specific angle of the bond between oxygen and hemoglobin in lungs, which I don't know, but what interests me more is the question, why is it specific?
2
votes
1answer
178 views

Need of Creatinine Phosphate

In muscle cells most of the ATP's phosphate is with creatinine phosphate. So why is the displacement of the phosphate group done ? Is it because creatinine phosphate would give it's phosphate more ...
4
votes
1answer
103 views

How animals maintain their body shape after development to maturity?

I've recently read a book on evolutionary-developmental biology for laymen, and it described how a fetus is progressively divided into more refined zones of genetic activity. These zones, kinda like ...
5
votes
2answers
1k views

What is dental health like in animals?

Do animals suffer from tooth decay, such as cavities? Is it to the same extent as in humans, or do animal teeth decay more or less? If teeth decay in animals as well, are there natural strategies ...
3
votes
1answer
1k views

What is the purpose of Y-shaped adapters in Illumina sequencing?

Y adapters different sequences to be annealed to the 5' and 3' ends of each molecule in a library. The arms of the Y are unique, and the middle part, connected to the DNA fragment, is complementary. ...
4
votes
1answer
182 views

Zombie Ant Fungus?

Ophiocordyceps unilateralis is a parasitoidal fungus that alters the behavior of the infected. Source: Wiki page. How is the fungus able to alter the behavior of the infected to such specfic ...
1
vote
1answer
62 views

Why are Lymphatic trunks part of the Cardiovascular system?

According to Wikipedia the Terminologia Anatomica (international anatomy standard) the lymphatic trunks are part of the cardiovascular system instead of the lymphoid system. Why did they make that ...
2
votes
1answer
119 views

How can we distinguish blended flavors?

As far as I know, humans can distinguish between 5 basic tastes based on various molecules in food and their interactions. There's a level to all 5 so there can be an endless variety of tastes, and we ...
3
votes
2answers
609 views

What is an 'ex vivo' experiment?

Simple terminology question: Is there a hard boundary between in vitro and ex vivo? Is there a hard boundary between in vivo and ex vivo? Suppose a sensory neuron is electrically recorded in the ...
3
votes
1answer
50 views

Effect of arteriole dilation on vein

If an arteriole leading to a capillary bed is dilated will the pressure in the vein coming out from the bed decrease ? Will the velocity of blood in the vein change ?
5
votes
1answer
65 views

How do rodenticides with delayed effect work?

Most modern rodenticides are claimed to cause death no earlier than several days after ingestion. That's quite strange - once a chemical was ingested it will be absorbed in the digestive system and ...
3
votes
3answers
77 views

Would Bubling Oxygen Through “Dead Zones” Like A Fish-Tank Make Much Difference?

I am a dilettante when it comes to dead zones. I realize that they vary from fleeting algal blooms to continuous dead zones. For the continuous dead zones it would seem to me that adding a "bubbler" ...
0
votes
1answer
249 views

Organelles present in sieve tubes

I know that sieve tubes do not have ribosomes, nuclei and cytoskeletal elements. What other organelles does it not have? Does it have a cytoplasm?
8
votes
1answer
212 views

Is it a limitation of the eyes, or the brain, that we can't see a moving bullet?

Are the photoreceptors in our eyes not fast enough to register the fast moving bullet, or is the brain not powerful enough to make sense of something happening that fast?
2
votes
1answer
420 views

Which is the tissue damaging agent in krokodil (street desomorphine)

I've just read about krokodil and saw some quite hideous pictures about what it does to the human body. I guess just desomorphine alone wouldn't have this effect. Which ingredient(s) causes the ...
2
votes
1answer
205 views

Do people of the same height walk at the same speed?

I'm working on a project that concerns movement and the human body. Before I begin to experiment, I need an answer to a question I'm sure has an answer, but doesn't Google well. What I need to know ...
5
votes
1answer
69 views

How compatible are mammal wombs?

I had read about science working towards the creation of artificial wombs however I wonder how compatible are mammal wombs and connected systems to develop fetuses. What species are so compatible that ...
1
vote
2answers
77 views

Why can't we observe haplotypes directly?

I am completely a noob to biology and DNAs, but recently I am looking into EM-algorithm used in the case of re-constructing haplotypes from genotype data. I am just wondering what exactly in the ...
5
votes
1answer
48 views

What non invasive methods of estimating Body Time are there?

I found this article on estimating body time using molecular timetable of 168 genes. researchers looked at gene expressions and plotted them to 24 hour cosines curve with some pretty spectacular ...
7
votes
2answers
582 views

What exactly happens if during translation, an amino acid is not present?

Lets say that the cell wants to make a particular protein. Transcription of the appropriate gene is done and the mRNA is made. mRNA attaches to the ribosome and the translation is initiated in a ...
0
votes
1answer
50 views

What happens to potassium after an action potential?

If I understand right, after repolarization, much of the potassium is outside the membrane and much of the sodium / calcium is inside. How does it get back to the original concentrations (i.e. ...
2
votes
1answer
53 views

Can a chicken's lard become liquid depending on its diet?

On Cooking.se, somebody asked a question about the fat in chicken stock sometimes being liquid and sometimes solid once the stock has cooled. The only answer until now suggests that the difference is ...

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