1
vote
1answer
95 views

How are the correct tRNAs transported to the ribosome?

I have been trying to understand how the tRNA transporting the correct amino acid required by the ribosome reaches the ribosome. The only way I can imagine this happening is that all types of ...
2
votes
2answers
77 views

Why does the mixture of infant formula with saliva provide an ideal breeding ground for disease-causing micro-organisms?

From: http://www.nal.usda.gov/wicworks/Topics/FG/Chapter4_InfantFormulaFeeding.pdf Discard any infant formula remaining after a feeding. The mixture of infant formula with saliva provides an ideal ...
0
votes
1answer
192 views

Why is the liver the only internal organ of the human body to regrow?

Related to my earlier question, "How does the human liver regrow?", am curious as to why the liver is the only major organ that has this capability? Why is it that other major organs, such as the ...
3
votes
1answer
93 views

When was the purpose of bone marrow discovered?

I'm currently reading William Cheselden's book Osteographia or The Anatomy of the Bones, which was published in 1733 (for the pretty pictures, naturally; not up to date anatomy). When he addresses the ...
5
votes
1answer
504 views

Smallest unit on which selection can act

Traditionally, the individual was considered to be the smallest unit on which Natural Selection (NS) acts. Today, we usually consider the gene as being the unit of NS. Of course, we should also ...
3
votes
3answers
321 views

Is there variation of AT/CG ratio along species?

Chargaff's rules say that the number of Adenine of the number of Thymine in a genome are equal (nA=nT) and similarly nC=nG. This makes obvious sense knowing that C binds to G and A to T. But what ...
3
votes
3answers
407 views

What species have had their genomes sequenced/are being sequenced?

The human genome project released it's first complete genome nearly ten years ago. Since then many species have also been sequenced. I am trying to find a list of completed (and possibly ...
0
votes
1answer
208 views

Why are human eye colours limited?

Related to the question What causes the colors we see in eyes?, I am wondering why human eyes are restricted in colour. Most common eye colours are blue, green and brown. Why not yellow, orange, ...
2
votes
1answer
28 views

potency in preformed germ-line

In organism that have a preformed germ-line like Drosophila where germ cells are pre-allocated in the oocyte, are there technically no adult pluripotent stem cells since germ line cells can't be ...
2
votes
2answers
73 views

Tree census data for Sweden/Scandinavia?

Is anyone aware of any attempts to count or approximate the number of trees there are in Sweden or Scandinavia? I have a small popular science side project for which this would be useful
1
vote
1answer
572 views

What determines the size and shape of a cell

What determines the size and shape of a cell? They differ at different tissues / organs/ species
0
votes
1answer
38 views

What determines the strength of a tree

What determines the strength of a tree. A morphologically strong looking tree found broken down at trunk. can we determine the strength/ life of a plant
4
votes
1answer
60 views

Is there differences in components of saliva among species

Are there differences in the components of saliva among species? Also, do the functions of saliva differ between species?
1
vote
1answer
31 views

Is it possible to suffer from hyperthermia by spending too much of time in the hot springs?

People may tend to spend time in a hot water spring. Is it possible to get hyperthermia (like a sun stroke) due to this?
4
votes
1answer
82 views

Why is there sperm mitochondrial suicide?

The mitochondria in the sperm are digested upon entry into the egg, making mDNA inheritance exclusively female. What is the advantage of this? Wouldn't some male mDNA be beneficial because of the ...
0
votes
1answer
623 views

Is there any natural blue rose?

I had recently read an article that the possibility of having natural blue rose is extremely rare because of the absence of delphinidin in most roses. Are all blue roses just a product of ...
0
votes
3answers
109 views

What type of insect is this?

I'm naturally thinking this is a bee, but I cannot find it anywhere in any insect identifiers. I caught this picture on top of my doorway, it's about 1 1/2 inches in length, and its torso seems to be ...
2
votes
1answer
144 views

How does electroporation mediated recombination work?

For yeast and other organisms, DNA can be readily taken up into the cell naturally or through membrane disruption. What does applying a voltage to cells do exactly that allows more recombination to ...
0
votes
1answer
64 views

Creating expression template from PCR: What annealing temperature to use?

I am creating a transcription template for expression in PURExpress and was confused about the annealing temperature to use. I have two primers with the T7 promoter and an RBS on the forward primer ...
2
votes
0answers
347 views

What is the difference between “lineage restriction” and “differentiated” in terms of stem cell biology

Is there a subtle difference between these two concepts or are they basically the same thing? When I mean differentiated, I don't mean terminally differentiated.
-1
votes
1answer
41 views

Axial skeletal system

I was curious about a fact given in my biology textbook as to why the Japanese have 3 pairs o floating ribs unlike the rest who have just two?
9
votes
2answers
352 views

How does the genetic code evolve?

After looking at this question, some other questions poped in my mind. The DNA code is redundant, there are 20 amino acids for 64 possible nucleotide combinations. Therefore some amino acid are coded ...
3
votes
2answers
97 views

Why ducklings are yellow?

Why ducklings are yellow, what the evolutionary background for this? How could it help to survive? UPDATE I agree with comment below, I did remember then that ducks are wild animals too (when I ...
0
votes
1answer
34 views

Can we remove impacted teeth by key hole surgery?

Can we remove impacted teeth by key hole surgery, rather than an open technique, like lithotripsy?
1
vote
1answer
109 views

What is Growing on These Tree Leaves?(Image)

I found a seemingly diseased tree when I was out playing tennis yesterday... What is growing on this tree leaf? Is this a disease? If so, is it contagious? I have zero knowledge in botany, but I'm ...
0
votes
1answer
34 views

How to Diagnose this hepatitis A, B and C case?

Male patient who is working in the hospital and may be infected with contaminated blood had hepatitis with genome IA 5 years ago. His hepatitis A at that time was confirmed with the rise of anti.HAV ...
12
votes
2answers
2k views

Is there any use of CO₂ in human body?

We all know CO₂ as a waste product of metabolism . Does CO₂ have any helpful role , apart from having a role in pH of blood ?
2
votes
1answer
110 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
63 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
1k 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
50 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
125 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
346 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
60 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 ...
10
votes
1answer
134 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
29 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
369 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?
1
vote
0answers
19 views

Can antiviral antibodies help viral infections which has many serotypes?

For instance Dengue virus has four serotypes. Infection by a different serotype causes only a more serious infection. 2) Which are the most common virus infections that has many serotypes?
2
votes
2answers
223 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
88 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 ...
2
votes
1answer
30 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
577 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
195 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
289 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
360 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
224 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
126 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?
2
votes
1answer
68 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
75 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
42 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 ...

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