2
votes
1answer
406 views

What controls the breast size?

I am not a biology student, just a curious person. To be specific, I'm talking about humans and specifically about females. I know that it might apply to other mammals. What controls the size of ...
1
vote
0answers
40 views

Why is important to get saturated fatty acids from diet?

I am thinking why our body must get saturated fatty acids from diet. We can make them, since they are not essential fatty acids. The body can make all fatty acids except linoleic acid and ...
4
votes
1answer
1k views

How does paracetamol interfere with immune system?

Paracetamol is used to reduce body temperature when it is to high. The high body temperature (fever) is known to be an indication that immune system fights against an infection. In this context I ...
3
votes
1answer
140 views

What kind of caterpillar is this?

I've made a photo using the reversed 58 mm lens and my cropped DSLR: Could you please help? I really don't know where this came from. I found it in Russia.
0
votes
1answer
44 views

Complexity in creating transgenic animals (e.g., mice)

Many papers I have seen describing transgenic rodent models (and presumably applicable to other model organisms) involve the knock-in, or modification to, a single gene, possibly two genes. With ...
3
votes
2answers
97 views

Do dolphins really sleep?

I have always wondered, if dolphins sleep with one eye opened, do they really sleep at all? According to this article dolphins indeed shut down their brains. I already googled it. No help from ...
3
votes
2answers
82 views

Is there a way to measure the amount of bytes that are possible to encode in a DNA molecule?

When I saw a DNA molecule for the first time, it kinda reminded me of a hard drive. It consists of slots and there are some possible combinations for each slot; in the hard drive these possible ...
1
vote
1answer
72 views

Is there an optimal illumination level for human habitats/workplaces?

I know of melanopsin, a photo pigment in mammal eye that helps regulate circadian rhythms. It responds most strongly to blue spectrum light. There have been experiments that demonstrated that ...
4
votes
0answers
55 views

Does preservation in ethanol alter leaf litter mass?

I have benthic samples that were collected with an Ekman dredge from some small ponds. The samples contain quite a bit of coarse particulate organic matter (CPOM, basically dead leaves). I would ...
2
votes
1answer
115 views

What's the difference between a free chromosome fragment and an extrachromosomal array?

This is reference to a review on C. elegans mosaic analysis by Yochem and Herman, in which the authors make a distinction between free chromosome fragments and extrachromosomal arrays. For the ...
2
votes
3answers
1k views

Improving Gel Extraction yields

How can I improve my Gel Extraction yields. We use the standard protocol from Qiagen, gel extraction, dissolve in QG buffer at 42C and purify via anion exchange columns. However, with 500 ng we ...
3
votes
0answers
78 views

How does LCR compare to Assembly PCR

The question pretty much explains itself. How do the two methods compare? I've always used Assembly PCR but the method is prone to mistakes and I'm curious how it compares to Ligase Chain Reaction ...
0
votes
1answer
97 views

RACE pcr product

I'm a molecular bio novice, and I'm trying to understand the differences between regular PCR and RACE PCR. If it wanted to sequence my PCR product that might be hundreds, if not thousands of bps ...
4
votes
2answers
3k views

Why is that all the animals can swim in water without learning to swim but humans cannot?

I had a question since I was a child. I was always curious that all the animals can swim in water. They don't need any training or to learn swimming. But humans need to learn to swim. Why ? I am a ...
-2
votes
1answer
132 views

Are ape communities more “anarchist” or “communist” in structure?

I am using these terms because we can imagine them quite good, I guess ;) By "anarchist" I mean that the ape wants to live without the rule of others apes(same biological race or other) and he pursue ...
4
votes
1answer
187 views

What is a simple protocol for staining cells in suspension?

I am an engineering student studying how electric fields affect cells, specifically the phenomena of electroporation in living cells. I know that electroporation is widely used for introducing genes ...
8
votes
3answers
159 views

What would cause E. coli to change from filamentous growth to normal growth?

In my lab we've observed a phenomenon in which a culture of E. coli is found to shift from normal rod growth to filamentous growth and then back to normal rod growth again several times over the ...
2
votes
1answer
61 views

Are (baseline) high blood levels of melatonin associated with either circadian rhythm or mood disorders?

(Exogenous) melatonin is administered at night for treatment of circadian rhythm disorders, but melatonin taken during the day is linked with depression. I would like to know if high blood levels of ...
3
votes
1answer
90 views

How compatible are mammalian digestive systems?

I'm interested in what kinds of nutrients mammals extract from food and would like to know how similar are the outputs of these systems. For example, if it is possible to successfully replace one ...
1
vote
2answers
83 views

Do individual (free) nucleotides base-pair with other free nucleotides?

I had a student ask me about this and my google-fu let me down. He asked if individual nucleotides (not in a nucleic acid) base-pair with their complementary nucleotides, essentially forming many ...
3
votes
0answers
105 views

Is there a standard definition for plant “maturity”?

Is there a species-agnostic metric for identifying plant maturity? There seems to be plenty of literature defining life-history stages for specific crops, but it is not clear if there is a generic ...
2
votes
1answer
164 views

ChIP-seq and the output of SPP

I have been processing some ChIP-seq data with the R package spp. I looked through the literature (ENCODE uses it) and it seemed that spp is indicated as a good program to use. I have found and ...
1
vote
0answers
23 views

What is the efficacy of Pertussis booster vaccine among different age groups?

The Murray Microbiology book says that it is prefentially 10 years, similarly Estonian and Finnish health associations. However, my professor says that it can be 5-7 years. I started to think if the ...
1
vote
1answer
481 views

Relation between goose bumps and temperature

As we all know, cold weather will cause us to have goose bumps. I honestly don't know why (1), because our skin contracts? Apart from that something quite contradicting happened this morning. I was ...
6
votes
2answers
381 views

Why does sexual selection evolve beautiful features?

First question here. I have a very raw understanding of sexual selection: Say a group of females of a certain species "likes" some feature of a certain groups of males; by "like" I mean some ...
2
votes
0answers
39 views

Vitamin and mineral contents of common fruits

I'm looking for nutritional data, mostly vitamin and mineral contents of common fruits, such as apples, bananas, oranges, kiwis etc. Are there scientific (published and peer-reviewed) sources that ...
3
votes
2answers
121 views

High sequence similarity but start codon isn't methionine

I have noticed in a particular genome sequence of a prokaryote that various regions in a sequence share similarity which is high(>80%) with known proteins. However, the start is not a methionine. Is ...
2
votes
1answer
61 views

Indestructible Super Shrimp

How are shrimp and other animals able to not be crushed by the 1000x greater pressure at the bottom on the Mariana trench? Wiki says the trench is home to "large living creatures such as a sole or ...
8
votes
2answers
105 views

Where can I find historical data on world-wide ecology parameters?

I hope this is the right StackExchange forum for such a question. I'm looking for large data sets on world-wide ecology parameters, such as annual temperatures by latitude, annual rainfall, CO₂ and ...
1
vote
1answer
99 views

Agony, Hydrophobia and viruses in the light of evolutionary principles

I'm undergraduate physics student, but I've always been interested in biology. So I have a couple of questions about an application of the evolutionary principles to practice. Agony as the last ...
6
votes
3answers
2k views

Why do neurons die so fast without oxygen and nutrients?

Some human tissue can survive without oxygen a couple of minutes, even hours. Why are the neurons are so "weak" and depends so much on oxygen and other nutrients and cannot live without them for ...
1
vote
0answers
97 views

Why aren't antheridia and archegonia touching?

Antheridia and archegonia are the two male and female gametangia, respectively, and they are found in bryophytes. To cause fertilization, usually a thin film of water must be present for the sperm ...
7
votes
2answers
340 views

In humans what is the last metabolic process to cease after death?

After death which of our body's metabolic processes will continue functioning for the longest?
1
vote
2answers
610 views

How do animals decide what to eat and what not?

I want to know this in particular about animals that no longer eat what they used to eat. The best example in my opinion are chickens. Chickens are often held to eat all kinds of food we would ...
1
vote
1answer
151 views

Are there any viruses or bacteria which have evolved to withstand higher temperatures due to fever

My question was raised after receiving this information: The primary reason the body raises its temperature (via the Hypothalamus in this case) is that bacteria and viruses tend to optimally ...
5
votes
1answer
372 views

What is the biological mechanism underlying caffeine intolerance? (CYP1A2 or other?)

As far as I can tell, caffeine metabolism occurs primarily via the CYP1A2 enzyme. I am curious as to whether mutations in the CYP1A2 gene are associated with caffeine intolerance. Some site that is ...
1
vote
0answers
34 views

If a receptor is inhibited throughout embryogenesis, could there be observable phenotypic differences in the adult?

So I read a journal article entitled "Maternal hypoxia and caffeine exposure depress fetal CV function during primary organogenesis" (Momoi, et al., 2012) and in essence the article speaks of the ...
5
votes
1answer
493 views

If fever is a natural immune defense, why do people take drugs to lower it?

If fever is a natural defense against pathogens, why do sick people take NSAIDs to reduce the fever?
-3
votes
1answer
116 views

How much can be said about behaviour (future) based on bloodgroup?

My bloodgroup for example is A+. How much information is knowing my bloodgroup? How much information can be known from a blood sample? I expect you to be able to clone if known a complete DNA sequence ...
3
votes
0answers
59 views

Sequencing rtPCR product

So I have a validated set of primers for rtPCR from Biorad that contains SYBR green. If I do rtPCR, can I use the rtPCR product after purifying it with a Qiagen PCR purification kit? Also, I'm under ...
5
votes
1answer
97 views

Can cirrhosis be caused by physical compression of the body?

On a random forum, a member speculated that their cirrhosis was caused by wearing tight-fitting clothing such as a girdle or corset. This leads me to the following question: Question: Can ...
2
votes
0answers
60 views

Might a previously administered MPSV4 vaccine react with a newly administered MCV-4 vaccine?

This is a hypothetical situation. Meningococcal polysaccharide vaccine (MPSV4) is a vaccine against Neisseria meningitidis. MCV4 is a conjugate vaccine. I would like to know if the polysaccharide ...
9
votes
1answer
280 views

When does weak selection produce qualitatively different results from strong selection?

In evolutionary game theory, it is typical to model organisms as having a base fitness that is modified slightly by the game interaction. The ratio of the game effect versus the base fitness ...
3
votes
1answer
473 views

Long term liquid food diet by blending/grinding all quality foods one would normaly eat, not any weight loss or prepared drinks

I want to know what are the effects of not using your teeth to grind foods but preparing it before eating with blending and grinding them into a liquid. Here I am not talking about any weight loss or ...
5
votes
1answer
162 views

What is the minimum population size that Hardy-Weinberg calculations can be applied to?

I'm trying to find out if a particular allele is in Hardy-Weinberg disequilibrium, but the data is poor. What's the minimum population number that you can use to get any sort of respectable ...
1
vote
0answers
84 views

Cereal Alpha and Beta Amylase temperature range and reaction rate

This question is motivated by a practical application in bread making. While it is well known which are the optimal (highest reaction rate) temperatures for both alpha and beta amylase, I am not able ...
4
votes
1answer
176 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
58 views

Is there an animal which, when eaten by other animal, poisons the predator and gets out of it's stomach?

It was a question in one competition, but it remained unanswered and i am curious about an answer. There was a hint: American bullfrog but i can not find any example of this behaviour on the web.
1
vote
1answer
134 views

What part of the cactus photosynthesizes?

In general, plants photosynthesize through their leaves and, to a much lesser extent, through their stems. Cacti, however, have no visible leaves, but instead spines. In what part of the cactus does ...
2
votes
1answer
89 views

Is Hypericum Perforatum (St. John's wort) a C3 or C4 plant?

I've been curious as to which photosynthetic cycle St. John's wort uses to synthesise glucose and more complex carbohydrates. I know it probably won't be the crassulacean acid metabolism (CAM) cycle ...

15 30 50 per page