2
votes
1answer
133 views

How does GTP help in the step of codon recognition?

The anticodon of an incoming tRNA base pairs with the complementary mRNA codon in the A site.Hydrolysis of GTP increases the efficiency and accuracy of this step. How does GTP do so ?
4
votes
1answer
71 views

What is the advantage of the way eukaryotes initiate translation?

The eukaryote and prokaryote mechanism for translation is slightly different. Is there any advantage of the eukaryote translation mechanism ? Edit : I specifically want to know why eukaryotic ...
8
votes
2answers
3k views

why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon ? Why is there a need for an initiation codon ? Can't translation start with different codons?
1
vote
2answers
59 views

Is this necrotizing skin infection caused by Staphylococcus aureus?

A 5-year-old boy returns from summer camp with several minor cuts and abrasions on legs. He has fever and extensive cellulitis, subcutaneous tissue and muscles are involved. Necrotic tissues were ...
1
vote
1answer
184 views

Does animal fat and meat contributes differently to our body?

Is animal fat harmful to our body or is it harmful if the amount eaten exceeds a certain amount? I have heard fat is more concentrated than protein. If I am correct then we can get more energy from ...
2
votes
1answer
575 views

Human body power consumption in still state

I'd like to know what kind of power human body needs to maintain life, in still state (average daily power consumption of an average man is also of interest). In terms of watts. I've only managed to ...
8
votes
1answer
75 views

What does the evidence suggest about how Neanderthals became extinct?

According to "Neanderthals: Facts About Our Extinct Human Relatives" (Szalay, 2013), Neanderthals dominated Europe during the last Ice Age, but may have died out before the arrival of Homo Sapiens ...
11
votes
1answer
164 views

Are there specific conditions that allow humans to see ultraviolet wavelengths

It is fairly common knowledge that the lens in its normal state absorbs ultraviolet (UV) radiation. An interesting notion has come up from time to time in my reading that suggests there are a small ...
2
votes
0answers
38 views

Elevated transaminases after blood transfusion?

This sparks HCV immediately in my mind. However, there may be other possibilities too. What can you deduce from elevated transaminases if you only know that the healthy adult patient received blood ...
1
vote
1answer
1k views

Can food swallowed when a person is upside down reach the stomach?

If a person positions himself upside down and swallows food, will it reach the stomach against gravity? If so how?
4
votes
2answers
484 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 ...
2
votes
2answers
114 views

What are the statistical tools for distinguishing molecular analogy from homology?

Scientists have developed statistical tools that distinguish "distant" homologies from coincidental molecular homoplasy in extremely divergent sequences. What are these tools?How are they used ? I ...
3
votes
1answer
36 views

HIV-RT nucleotide contact residues

I'm investigating HIV-RT 3KLF and 1LWF trying to find a perfect pose of thymine. Which residues on HIV-RT is Thymine supposed to contact on 3KLF and 1LWF? Where exactly is the nucleotide binding ...
1
vote
1answer
880 views

How effective are restriction enzymes in protecting bacteria?

Bacteria use restriction enzymes to cut DNA of bacteriophages. Virus mutates really fast. Won't a point mutation in restriction site render the restriction enzymes of the bacteria useless ? So how ...
1
vote
1answer
372 views

Does a fully-resolved phylogenetic tree have to be dichotomous?

I read that wherever there is polytomy there is an unresolved pattern of divergence. I don't understand why this is so. When divergence takes place, is it necessary that there will be division into ...
3
votes
1answer
479 views

What hair color will result in someone inheriting both blond and ginger genes?

Both the genes for blond hair and ginger hair are recessive, so they need both parents to give the same gene for it to take affect. What happens when a person has 1 copy of a recessive gene and ...
1
vote
1answer
555 views

What should be evaluated in food decomposition experiment?

Briefing Some days ago I noted that 3 cookies left on my desk since 3 months ago are still "fresh", and by that I mean... not spongy like some cookies that get soft after some time outside. However ...
-1
votes
2answers
337 views

What would happen if you slowly crushed a live brain?

In a hypothetical scenario, if you cut open a person's skull to show the live brain, and then you slowly start to crush it.. At what point would the person loose consciousness? What would the ...
4
votes
3answers
149 views

Abnormal Prolactin Level [closed]

I want to know what makes the balance of the Prolactin abnormal. Is that related to the presence of a nodule near the pituitary?
3
votes
1answer
74 views

In our solar system which other planet could have been in the “habitable zone” in the past?

With changes in our solar system, such as planets moving away from the sun and the reduction in solar radiation, which other planets in our solar system could have been, in the past, in a suitable ...
2
votes
2answers
82 views

Assays during drug discovery

After researching the definition of Assay, I am left with the idea that an assay refers to scientific screening. It could be of chemicals, microbes, etc. I understand that during drug-discovery ...
2
votes
1answer
51 views

How can a respiratory infection lead to a skin infection?

Example of a case: 5 children develop a bright red rash on the face and turns violet after a few days and then disappears. Then maculopapular rash appears on the trunk, buttocks and extremities. It ...
3
votes
1answer
1k views

RNA-seq analysis - q-values in cuffdiff

I'm using cuffdiff 2.1.1 to look for differential gene expression between two conditions. Each condition has 2 biological replicates. The results I get look promising from a log fold change ...
1
vote
1answer
81 views

Do mitochondrial DNA have repair enzymes?

Mitochondria are considered endosymbionts originated from a prokaryote. So, do they have a DNA repair mechanism ?
4
votes
1answer
218 views

Inheritance of Huntington's disease

People with Huntington's disease have HTT genes with more than 37 copies of CAG repeat. The risk of extra copies being generated is higher during sperm formation than during ovum formation. Why is it ...
3
votes
1answer
250 views

How to distinguish those flowers in outskirts: hawkweeds (Hieracium), hawksbeard (Crepis) and hawkbits (Leontodon)?

How to distinguish those flowers of the forest outskirts: hawkweeds (Hieracium), hawksbeard (Crepis) and hawkbits (Leontodon)? I am not asking about concrete species it should be extremely hard since ...
1
vote
1answer
115 views

Why can't we propose a solid theory regarding origin of life?

What information is greatly lacking which does not allow us to propose a solid theory for origin of life ?
8
votes
1answer
146 views

Model for fluctuating selection

Is there any mathematical model to predict the behaviour and long-term consequence of counter-acting selection at different time scale? For example, let's consider the bi-allelic gene A, with alleles ...
0
votes
1answer
41 views

Can acid-fast M. tubercolosis obstruct alveoli?

I am not sure which word is the best here for colonisation of alveoli by acid fast-mycobacteria. I found this question, and I am getting confused by the term obstruction of alveoli because I tend to ...
2
votes
1answer
38 views

Which strains of C. diphteria are causing Diphteria toxin?

I got this question: Diphteria toxin is produced only by those strains of C. diphtheria that have which of the following characteristics? Encapsulated glucose fermenters lysogenic for b-prophage ...
3
votes
2answers
336 views

Factor causing Methicilin-resistance in MRSA?

I think the main reason is the natural selection that is causing methicillin-resistance. However, I am not completely sure what this means practically. Here, the original question: MRSA was isolated ...
2
votes
2answers
4k views

Why restriction enzymes cut (usually) at palindromic sequences?

Restriction enzymes usually cut only at palindromic sequences. Is there any specific reason for that ? Is there any advantage for bacteria if it cuts up virus at this type of sequences ?
0
votes
1answer
197 views

What is the difference between these worms: Caenorhabditis elegans and Eisenia fetida?

I love worm composting (I use red wiggler worms), but wondering how similar or different the Caenorhabditis elegans and Eisenia fetida are?
6
votes
1answer
210 views

Why are women more susceptible to radiation?

The answer to this question on the Space.SE indicates women are more susceptible to radiation in space than men. Why is this the case? Is it merely that women have less muscle mass (which being ...
3
votes
1answer
157 views

Are similar smells usually based on similar chemicals?

Building off of this question: Why does freshly cut grass smell like a watermelon?, is it usually the case that things that we perceive as having similar smells are, in fact, the same or a similar ...
3
votes
1answer
116 views

copper vs aluminum, what's the safest for health?

I'm working on a mini project for a milk dispenser machine, using a peltier device to cool the milk down, I have to choose between a copper or aluminum cooling block (see pictures bellow). But I'm ...
2
votes
1answer
146 views

What happens during metamorphosis?

We were studying butterflies in class and I asked my 7th grade teacher, but she deemed the concept "too complicated." I'm really curious now, not only about butterflies but insects in general... ...
0
votes
1answer
138 views

Why do bats huddle during late fall?

In the late fall, bats hibernate in clusters with many bats pressed together and holding on to one another. Which of the following supposed advantages of huddling behavior is, in reality, not true? ...
2
votes
1answer
881 views

Why does freshly cut grass smell like a watermelon?

I found that, when I smell watermelon aroma outdoors, someone nearby has mowed the grass. Is there an underlying basis?
4
votes
1answer
177 views

Why do mosquitoes not collect blood after platelets activate?

This may be anecdotal... The Indian sub-continent is in the rainy part of summer. It follows the mosquito population goes up. So when I sliced my palm, I expected the mosquitoes to collect there in ...
1
vote
1answer
174 views

Suggestions for an experiment? [closed]

I would appreciate suggestions for my year-long AP Biology project. Such a project would consists of a standard experiment, to be done over the period of a year, so it would have >to be fairly ...
2
votes
1answer
857 views

Can Naegleria fowleri enter through your ear?

Is it possible to get infected with the amoeba, Naegleria fowleri, through your ears, or is the nose the only way it can enter to cause infection? How commonly is it found in your stool as well?
9
votes
2answers
5k views

Why does it hurt when you take sweets, if you have cavities in your teeth?

When you have cavities in your teeth taking any sweetend drinks or food causes sensitivity or pain. What could be the reason?
4
votes
1answer
72 views

Missing cells from immunopanning

Why do I not have any cells left in my positive panning plate after transferring from the negative panning plate during immunopanning? I am trying to purify retinal ganglion cells from postnatal rats ...
2
votes
1answer
852 views

Difference between 'Orbit' and 'Globe' in eye anatomy?

What's the difference between 'Orbit' and 'Globe' in eye's anatomy. Do they refer to the same ? I encountered this in this text: ... ciliary ganglion, which is approximately 3 mm in size, and ...
4
votes
2answers
379 views

Why doesn't human consumption of plants cause infectious diseases the way consumption of animals can?

At first I want to clarify that I do know that there are naturally poisonous plants and plants that can hold radioactive stuff or toxic material from the environment. What I mean by "diseases" (I ...
2
votes
1answer
242 views

How to deduce if RNA virus infection or DNA virus infection

Is there any general rule to say this must be RNA virus infection and the other one DNA virus infection? Example of a case: 5 children develop a bright red rash on the face and turns violet after a ...
1
vote
1answer
67 views

Can someone provide resources on human electromagnetic frequencies?

Pardon all of my questions below. I'm basically looking to find online resources regarding my inquiry. If you can answer any of them off the bat, that would be awesome!! It seems that humans and ...
1
vote
1answer
211 views

Characteristics of life

If all of the characteristics of life are required for something to be defined as living, how can we account people or other life that can not reproduce?
3
votes
2answers
2k views

What is the genetic basis of blood type (ABO) system?

What is the genetic basis of the A/B/B+/O/etc. blood type system? Are there definitive loci that correspond to each or can multiple different genotypes produce the same antigen profile? Also, is the ...

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