6
votes
1answer
347 views

Which of the cell types commonly found in mammals has the greatest number of mitochondria?

This is basically a fun question, inspired by this answer on scifi.se. So, which cell type will have the greatest number of mitochondria? Obviously, I am talking about wild type, healthy individuals ...
6
votes
0answers
24 views

Can a lizard shed a regrown tail again?

Some lizards are famous for their ability to voluntarily shed their tail to elude predators (Autotomy). After a while, the tail will be regenerated, though with slightly different qualities, as ...
-3
votes
0answers
15 views

Why does the growth of hair are faster than the growth of other cells in humans? [on hold]

We might have observed that growth of hair is more than growth of any other cells in human body ? Why is it so ?
0
votes
0answers
17 views

Why 'blood vessels' and not 'blood tubes'? [migrated]

I have a silly question. The way I imagine arteries and veins are as tubes that arise from one part and carry blood to the other part. Why do we call them 'vessels' (which reminds us of cooking ...
1
vote
0answers
74 views

Measuring a plant's electric activity any instructions where to place electrodes?

I would like to measure a plant's electric activity / voltage, I've looked online to find out where to place the electrodes and what type of electrodes to use but they seem to very wildly. Any ideas? ...
4
votes
2answers
86 views

Is the water transpired by plants pure H₂O, or does it contain trace minerals?

I'm considering the idea of drinking water that I trap from what is transpired by trees. Interestingly, is this water a fairly (or maybe even extraordinarily) pure form of H₂O, a remarkably pure ...
2
votes
1answer
42 views

What causes head hair to be different than body and face hair?

If you feel your head hair, it typically feels a lot softer and is easier to manage (comb, brush, fix) than a lot of other hair on your body - specifically I'm thinking about beard hair and pubic ...
32
votes
5answers
3k views

Is there an advantage to antibacterial soap?

There are plenty of different hand soaps out there, as well as hand sanitizers. Is there an advantage to soaps that claim that they're antibacterial vs soaps that just say soap? In particular I'm ...
4
votes
1answer
322 views

Is sexual selection evolutionarily advantageous?

Our biology teacher says that peacocks will soon become extinct because of bigger and bigger (and heavier and heavier) tails. Why natural selection did not eliminate sexual selection?
1
vote
2answers
47 views

What's read depth in VCF?

There is an attribute defined as DP (Total Depth) in VCF file format. For example, http://www.1000genomes.org/node/101. What does this attribute mean? If I get a value of like DP=128. How can be that ...
8
votes
2answers
98 views

How is it possible for only one in five children to have brown eyes when their parents both have brown eyes?

I have observed that parents having brown eyes had three female offspring with blue eyes, one son with green eyes, while only the youngest daughter had brown eyes. How can they produce so many ...
1
vote
0answers
25 views

How to be a Noah-esque biopirate and store the genes of every plant and animal [closed]

Preamble. Please criticize this idea. It is too romantic to be possible. All of the news about the sixth extinction got me thinking about it. Thanks The price of DNA sequencing for humans has ...
2
votes
1answer
31 views

Database of medically validated SNPs

I'm looking for all possible sources of clinically tested human SNPs. There is a handful of databases that store SNPs (like dbSNP), but I only need those that have validated presence/absence of ...
-1
votes
0answers
29 views

What did the transition from ovipary to Hemotrophic viviparity look like? [closed]

Most evolutionary changes happened slowly over countless generations. Richard Dawkins illustrates this beautifully in Greatest Show on Earth when he describes lining a rabbit up next to all her ...
0
votes
1answer
17 views

Which pair of primers should be used to amplify the ORF in PCR? [on hold]

So I want to choose the correct set of pair of primers to amplify the ORF of the gene that corresponds to amino acids in a protein. The start and stop codons are underlined. (I know that these need to ...
2
votes
1answer
24 views
0
votes
0answers
24 views

IC50 and area under the curve

I was hoping to get some clarification on how drug response data (i.e. IC50) are presented. On publicly available datasets like Genomics of Drug Sensitivity in Cancer, area under the curve (AUC) ...
3
votes
0answers
22 views

What is the meaning of conservation site in miRNA-mRNA pairing context?

I am not biologist and just work in Bioinformatics field. Does anyone know what is the meaning of conservation in the context of miRNAs and their pairings to mRNAs? Example: Each of these duplexes ...
2
votes
2answers
149 views

How does DNA damage cause ageing in yeast?

As I understand it, in yeast ageing there is daughter cell and mother cell. The daughter cell is has newly "fresh" DNA and mother cell dies after some counts of replication. What happens to the ...
11
votes
5answers
683 views

What is meant in biology by the term “evolved”?

A student asked me this the other day and I thought that I would ask it again here. If one organism is said to be "more evolved" than another, what exactly does this mean?
4
votes
2answers
53 views

Exhalation while holding breath

If you inhale to your maximum capacity and hold your breath for an extended period of time, it begins to feel uncomfortable; slowly releasing your breath at this point seems to provide relief from ...
4
votes
3answers
946 views

Why is wind cold for humans? [closed]

Coming out of the pool the other day, I felt very cold because I was wet and the wind picked up. My idea is that a "cold" feeling should be associated with low temperatures, but it's indeed wrong. ...
0
votes
0answers
25 views

Why do human have continuously-growing hair on their head? [duplicate]

Why do hair continuously grow on human heads, while the same doesn't happen on other parts of the human body? Where there are hair, they only usually grow to a fixed length; but they seem to have no ...
2
votes
1answer
27 views

Which process is right to describe V(D)J recombination? RAG-1 and RSS recurring process

I'm studying V(D)J recombination. I think I have two incompatible books about explantaion of the process. Which is right? In Molecular Biology of the Cell 5th Ed., firstly RAG (-1?) combines to RSSs ...
14
votes
2answers
532 views

How do small animals make loud sounds?

Walking past the park today, I heard a cicada so loud I thought at first it must be some sort of large power tool. How is it that that very small animals like cicadas (crickets, etc.) can make such ...
3
votes
1answer
57 views

Does learning increase the number of neurons in the brain?

I am attempting to understand neurogenesis related to learning. Does learning increase the number of neurons in the human brain? What would be some good scientific publications to read?
0
votes
1answer
37 views

How copy number variation thresholds are defined in GISTIC

I am having trouble trying to understand how GISTIC discretize copy number variation to values -2, -1, 0, 1, 2. I am using TCGA copy number variation for ColoRectal Adenocarcinoma. In cBioPortal FAQ ...
3
votes
1answer
32 views

What is the relationship between W, X, Y and P, M retinal ganglion cells?

In Guyton and Hall Textbook of Medical Physiology (12e) the retinal ganglion cells are classified into W, X, and Y types. However in Gray's Anatomy (40e) they are classified into Midget and Parasol ...
-1
votes
1answer
17 views

is left brachiochephalic vein and left pulmonary artery is same?

I am reading about ligamentum arteriosum which connects the left pulmonary artery and descending aorta. But I am seeing that if any figure shows left brachiochephalic vein it does not show left ...
3
votes
2answers
32 views

Deciding a reasonable threshold for copy number variation in a CNV (SNP array) TCGA dataset

Is there a methodology to select a reasonable threshold for copy number variation in a CNV (SNP array) TCGA dataset, to define when there is a significative alteration? Can I download CNV data for ...
-4
votes
0answers
19 views

Southern blotting [closed]

i am a student at the University of Reading studying Biological Sciences and one of my modules is called Practical Recombinant Genes exercise. We were given some questions to answer for our exam ...
2
votes
0answers
15 views

Genetic tests on S. cerevisiae to determine mutation locus on genes

I am studying the metabolism of galactose in the budding yeast Saccharomyces cerevisiae. After a random mutagenesis screen, several mutant strains were isolated that grow well in glucose but are ...
-1
votes
0answers
18 views

Is spore print counted as organic material? [closed]

A friend of mine is travelling in the Netherlands and he came by a shop which sells spore prints. As far as I know, in my country it's illegal to get organic materials from other countries. I wanted ...
3
votes
0answers
14 views

Why is the administration of exogenous Anti-D not harmful to the foetus?

Haemolytic disease of the newborn can result from Rhesus incompatibility in utero. In this disease a Rh-ve mother becomes exposed to the antigens of a Rh+ve foetus by fetomaternal haemorrhage causing ...
0
votes
1answer
20 views

Ways the structure of the pancreatic acinar cell relates to its function?

So the pancreatic acinar cell synthesizes, stores and secretes digestive enzyme precursors called zymogens e.g. pepsinogen. The structure of the acinar cell shows that there is an apical and basal ...
6
votes
3answers
61 views

Mutation That Loses Stop Codon

Someone asked this in my class and my instructor wasn't sure in her answer, doesn't anyone know what happens in protein synthesis if a mutation causes mRNA to not possess a stop codon? Would the ...
2
votes
1answer
32 views

System biology and evolution: Book-recommendations

I have relatively good knowledge in evolutionary biology and in population genetics. I am getting more and more interested in the evolution of ... genetic developmental processes gene interactions ...
-2
votes
0answers
25 views

How many human cells will get affected at the prick of a pin? [closed]

Wikipedia states that there are 10^14 cells in a human body. My question is if I was to take a needle or a pin and pierce it just 2 mm in the body, how many cells will I be piercing? Thank you in ...
2
votes
1answer
23 views

If one endures the same form pain over a long period of time, would the pain begin to lose intensity?

Metaphorically thinking, if one endured the pain of constant burning for decades, would the pain slowly lose its strength?
2
votes
2answers
27 views

Defining Resistance and Sensitivity Thresholds for IC50

I have a dataset containing IC50 data for each of my cell lines and up to 80 drugs. Basically for each drug I want to be able to define an IC50 threshold where if a cell line has an IC50 above that ...
2
votes
1answer
24 views

T7 Tagging in Synthetic Biology

What is a T7 tag and can if be used to purify synthesized proteins? Is it charge based like a His tag?
0
votes
0answers
38 views

Can Kit fox and Red fox produce offspring?

Can a Kit fox (Vulpes macrotis) and a Red fox (Vulpes vulpes) together produce offspring? Would such a hybrid be fertile?
7
votes
1answer
709 views

Lumosity.com? Is it based on science?

I always see these Lumosity adds on TV, and I personally feel they are just trying to "sell me something". I did some layman's research(wikipedia) and read that "Studies of Lumosity's effectiveness ...
4
votes
1answer
462 views

What happens to the red blood cell in CaCl₂ solution?

Here's the problem: One red blood cell is placed in a hypertonic solution of NaCl, another is placed in a solution of CaCl2 equimolar with the NaCl solution. What would you expect to happen and why? ...
10
votes
4answers
847 views

“Same” DNA vs genes

It is often cited that humans share 99% (or 98%) of their DNA with chimpanzees. On the other hand it is stated that siblings share only half of their genes. What (if any) is the difference between ...
7
votes
1answer
312 views

How do female hormones cause blood to clot?

On most female-hormone supplements you get a warning that is something like this: The use of a combination hormonal contraceptives (CHC), like NuvaRing, is associated with increased risks of ...
5
votes
1answer
31 views

How are the physiological properties of mitochondria measured?

this is my first question on BiologySE. I am a Physics and Mathematics student currently doing a project on cell growth simulation. I am doing literature survey and I have a question about cellular ...
6
votes
2answers
106 views

Which part of human body sustains most pressure when standing up straight?

Let's suppose a healthy fit barefoot young adult standing comfortably on a flat solid surface. A reasonable guess is somewhere around the foot. But is it the ankle, the heel, or the Metatarsus?
1
vote
0answers
35 views

How nerves interact with other cells? [closed]

I read in a book by Mick O'Hare, that injuries inflicted by electric current are caused by tension of your muscles. Is that explainable only with physics or nerves really use electrical signal as ...
1
vote
1answer
31 views

Recommendations for an intro level virology textbook?

I'm a college sophomore, and I was just accepted into a research lab that works with retroviruses. Since I haven't taken any classes on the topic yet, does anyone have recommendations for good, ...

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