1
vote
0answers
26 views

How is saltatory conduction faster than conduction of unmyelinated fibers? [duplicate]

It's always the same explanation that currents are able to "hop" along Ranvier nodes instead of passing continuously along the axon making saltatory conduction more efficient than continuous ...
4
votes
2answers
96 views

Transmission of disease from mother to fetus

Can parasite, microbes be passed from mother to fetus through the placenta ? I know some like HIV can be.
1
vote
1answer
96 views

Detecting UV by humans

From my experience humans can detect UV - not by seeing it but by pain in their eyes. Many people (me too) feel pain when looking at UV lamps. When looking at sun through clouds I still can feel pain ...
2
votes
1answer
111 views

.Net DNA/Codon Parser

Does anyone know of an .NET (C#,VB.NET, maybe F#) DNA parser? If not I will probably make one, it doesn't seem like it would be hard. My general idea was to generate something that would report the ...
3
votes
3answers
75 views

Can genes that activate transcription factors also called be called transcription factors?

If the sole known function of a gene is to activate a transcription factor, would that gene also be considered a transcription factor, or is there a word for such genes that are further upstream on ...
-3
votes
1answer
56 views

Cellular components of blood cells

There are different types of blood cells in the human body i.e. red blood cells, neutrophils, basophils, eosinophils, monocytes, T-cells, B-cells. What are the cellular components of these cells? ...
3
votes
1answer
452 views

What is needed for a G-matrix?

I have been doing a lot of reading on quantitative genetics and the G- (and B-) matrix lately. I get the principle behind performing the analysis now but I am still not sure how to do it. I'd like to ...
4
votes
1answer
2k views

Difference between mutation and DNA damage

What is the strict difference between mutation and DNA damage? As far as I understand it, a mutation is an alteration in the genetic sequence, having "tricked" the repairing machinery and thus ...
1
vote
1answer
67 views

What is the strength of human cornea?

What is the difference of pressure a human eyeball cornea (cornea, lens and other elements separating vitreous body from air) can handle? Or asking differently: what the outside pressure should be to ...
2
votes
2answers
88 views

Termination of translation

What dissociates first - the last tRNA, mRNA and release factors or the subunits of ribosomes? I tried searching this from Lehninger but couldn't get a clean answer.
0
votes
1answer
115 views

cellular respiration

What are the effects of addition of these chemicals to actively respiring cells ? Which of them would lead to INHIBITION of aerobic respiration ? Would cytochromes be actually taken up by cells ? ...
5
votes
1answer
58 views

Calling for Free Online Data for Paediatric ECG?

I need free online data about heart murmurs to study these: heart murmur frequency , S2 heart sound frequency and its split, murmur timing, and duration, murmur intensity, S3 sound presence and ...
0
votes
2answers
141 views

Won't natural selection miss the overall minimum of a function?

Suppose we have a population of about 1000 with an environment that does not change a lot (e.g. the atmosphere is more or less the same) and we leave this population to evolve. From what I understand ...
1
vote
1answer
138 views

Why do I have a lot in common with my mother? [closed]

I have not spoken to my mother in 15 years but recently connected with her and her side of the family. I was primarily raised in a different sub-culture after the age of 4. As it turns out I ...
-1
votes
1answer
107 views

What are uses of fossils? [closed]

What are the geological uses of fossils and how could it be utilised? From The Institute for Creation Science: Fossils are typically found in sedimentary rock, almost all of which were originally ...
5
votes
1answer
71 views

Shade-loving Plants

In shade-loving plants, the light compensation point is reached at low irradiance because: A. Leaves have more chlorophyll per reaction center B. These plants have greatly reduced respiration rates ...
2
votes
1answer
60 views

Antibody production in secondary immune response

Can IgG antibodies be produced in the secondary immune response without the help of T cells? Is the affinity of antibody for antigens higher during secondary immune response?
6
votes
2answers
350 views

Why are humans and almost every species on earth symmetrical?

I admit I'm not very learned on the subject of evolution, I just started researching it for myself about a week ago. One of the things that I don't understand is why humans and almost every other ...
9
votes
2answers
13k views

Blood Pressure: Significance of difference between systolic and diastolic

I wanted to understand what is the difference between systolic and diastolic readings of blood pressure. I understand 120-80 to about 100-60 is considered normal but does the difference in the two ...
3
votes
1answer
164 views

Number of genes required to sustain life

Are there estimates of the minimum number of genes required to sustain life? In what I mean by life here, I don't include viruses.
3
votes
2answers
3k views

Presence of MHC on red blood cells

Do red blood cells have no MHC? (I have often heard that they do not.) If so why are they not destroyed by immune cells?
3
votes
1answer
65 views

Alternating Ovulation

I have often heard that right and left ovaries alternate in releasing ovum. Is it always true? What controls this rhythm? Is it simply because the other ovary is unresponsive to LH or FSH? If so, ...
6
votes
2answers
4k views

When designing primers how important is the GC clamp?

I'm designing a set of primers and reading about the principles of primer design one of which is: GC Clamp: The presence of G or C bases within the last five bases from the 3' end of primers (GC ...
4
votes
1answer
43 views

What are the molecular mechanisms that make the turtle brain more resistant to hypoxia?

I know that turtle brains, particularly those of individual species that hibernate and burrow are particularly resilient to hypoxia and any tissue damage secondary to a hypoxic event. What are the ...
4
votes
2answers
669 views

What is a “pure odorant”?

This article about testing for Alzheimer's, via changes in the ability to smell, said: She thought of peanut butter because, she said, it is a “pure odorant” that is only detected by the ...
2
votes
0answers
95 views

What to do with a DNA sequencer? [closed]

My school is very fortunate to have a DNA sequencer, and I want to find an opportunity to learn how to use it. I'm currently taking AP Biology this year, and I hope to do an independent study in ...
7
votes
1answer
267 views

Cytoplasmic determinants - protostomes and deuterostomes

Cytoplasmic determinants are spread unevenly in the egg, and so when embryo starts forming (cells start dividing), the determinants are also unequally divided between cell. This unequal distribution ...
1
vote
1answer
125 views

Creative ways to deactivate alpha-amylase taken from fungi

I can deactivate $\alpha$-amylase in ways such as extreme temperature controls, pH controls of the solution it stays in, or adding salt to the solution. However, are there any other unique or ...
4
votes
2answers
5k views

Why do ladybugs have a different number of points on their backs

Everytime I see a ladybug I ask myself this question. Why does every ladybug have a different amount of points on its back? Is it because of its age? Or because of its genes? Is it inheritable?
4
votes
1answer
127 views

Does the body lose energy or gain energy relatively when drinking or eating hot things?

Does the body lose or gain energy when drinking or eating hot things compared to more neutral temperature things? On the one hand, The body could somehow convert the heat energy into human usable ...
4
votes
2answers
123 views

Why don't amino acids get linked in the functional groups of acidic and basic amino acids?

There are 'acidic' and 'basic' amino acids like aspartate and histidine. When protein is synthesized with those amino acids, what ensures that the to-be-assembled amino acids will not bond to the ...
1
vote
2answers
118 views

Would it be correct to state that any biological difference between the sexes has to be found in the Y chromosome?

If the reason Why Men Don't Listen and Women Can't Read Maps is genetic, then one of the genes in the Y chromosome is to blame and in theory could be identified. Correct or incorrect?
-6
votes
2answers
243 views

Is love biologically useful? [closed]

I thought about this statement a while ago: Natural selection sucks, it says those who love too much (or too many) will die the easiest and fastest. Sad but true. Only family (biologically of ...
22
votes
1answer
521 views

Extremely rare occurence of Heart cancer?

The occurrence of Heart cancer (similar, but not the same as Rhabdomyosarcoma) is extremely rare, about 1 per year according to MayoClinic. The reason for this rarity is explained to be the ...
4
votes
1answer
330 views

Hypotonic or Hypertonic solution and why?

A doctor needed to administer 5% albumin to a patient. Albumin is normally administered dissolved in 0.9% saline solution. Since the physician did not have any 5% albumin solution, he diluted 25% ...
6
votes
2answers
2k views

Why do different bacteria have different shapes?

Why do different bacteria have different shapes? Is it only related to their function?
1
vote
1answer
35 views

Genotoxic agent and their metabolic pathway

What are the mechanics (set of biochemical reactions) allowing a given genotoxic agent to modify the mutation rate at a given spot? to induce only a given type of mutation (from Gs to Cs for ...
0
votes
1answer
107 views

Lizards are sometimes called cold-blooded because they depend on their surrounding temperatures to keep them warm.

Predict how the composition of the cell membrane of a lizard might change from winter to summer. Justify predictions. Can someone please help me figure this out. Does it have to do with fluidity?
0
votes
2answers
555 views

What are artifacts in microbiology?

What kind of objects can be qualified as artifacts? How do we distinguish such objects?
2
votes
1answer
51 views

Phenoptosis, behavior evolved for good of species?

I was reading this and felt like the argument is being made that organisms die for the good of species. Isn't this nonsense? This especially bugged me: "'Age-induced, soft, or slow phenoptosis'" ...
3
votes
1answer
408 views

Negative value on linear gene expression in microarrays

I am starting to use microarrays and maybe this is a dumb question: Using Illumina microarrays, linear gene expression can be negative? Or maybe some artefacts have been introduced? And, in this ...
0
votes
2answers
1k views

Genetically speaking, are dogs exactly similar to humans and chimps both?

Richard Dawkins mentions in his book The Greatest Show on Earth that dogs are exactly similar to both humans and chimps. Supposing that a cell contains the genetic similarity between 2 species, he ...
0
votes
2answers
159 views

Can you detect if a mutation is spontaneous or induced?

Is it possible to determine if a certain specific mutation had a spontaneous origin (for example from a mistake of the DNA polymerase) as opposed to an induced origin (for example, from some genotoxic ...
6
votes
1answer
2k views

The real definition of carbohydrates

Carbohydrates are often defined as compounds with only C, H, and O and the H and usually the O atoms are in a 2:1 ratio. Exceptions like deoxyribose exist, but why is it recognized as a carbohydrate? ...
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 ...
1
vote
2answers
5k views

Why is weight gain a symptom of Cushing's Syndrome?

Cushing's syndrome results from increased levels of cortisol in the body. Cortisol as I understand it however, promotes the breakdown of glycogen and amino-acids in the process of gluconeogenesis, to ...
2
votes
1answer
54 views

Fusion of neuron with a S phase cell

There was some experiment in which a S phase cell was fused with other cell and the other cell also began to replicate DNA. Would the same happen if fused with nerve cell ? Why or why not?
1
vote
1answer
110 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 ...
5
votes
1answer
152 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 ...
3
votes
1answer
479 views

Is there an optimal composition and length for protein linkers in FRET?

I'm designing a protein that I'd like to use in FRET reporting. General idea on the shape is: FRETprotein1--Linker--CleavageSite--Linker--FRETprotein2. I would like to know what AA are best for the ...

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