2
votes
2answers
294 views

Are there natural selection experiments that quantitatively agree with theoretical modeling?

Has anyone ever conducted an evolution experiment and quantitatively compared it to theory? For example, has anyone ever put bacteria in a million petri dishes filled with antibiotics and calculated ...
4
votes
2answers
57 views

Is there a term for when a detrimental gene can be positively selected for because of linkage to a very fit gene?

Let's say that some piece of DNA would be subject to extreme negative selection if it were independently inherited, but it is very closely linked to an extraordinarily fit gene, and so the complex it ...
0
votes
0answers
17 views

T cell sensitivity and persistence to specific bacterial proteins [on hold]

Currently, the standard tests for Lyme Disease measure antibody production after exposure to a bacteria, Borrelia burgdorferi. Often, the tests are performed too soon after infection, before ...
1
vote
0answers
19 views

Can you suggest me some books/articles about how female birds indicate receptivity to copulation? [on hold]

Where can I find informations about the topic? I need to find some examples. I also really need this particular information: I know that many female mammals display lordosis behavior that indicate ...
0
votes
1answer
14 views

Why does a dichotomous key offer only two choices at each step?

Why does a dichotomous key offer only two choices at each step? Is it mainly for simplicity?
0
votes
1answer
22 views

Do different emotions produce different tears?

Do tears of joy, laugh, grieve, and others contain different things or are they all the same?
1
vote
0answers
6 views

How does the brain know what to remember and what not?

People remember some information for example when learning for an exam, or remember to go to a shop after work etc., but we don't remember usually much other stuff like people passing us, what was the ...
0
votes
0answers
23 views

If life is found on Mars, what can be deduced about its possible common origin as Earth life? [on hold]

Assume that life is found on Mars, or anywhere out of Earth where it can be sampled and closely studied. Would we know if it is related with Earth life? By what primary means, what characteristics ...
1
vote
2answers
20 views

What is the most appropriate way to normalize gene expression data?

This question comes because reading a paper about normalization of gene-expression data, is not clear if the method for normalize the data is just for RNA-Seq data or could be applied also for ...
1
vote
0answers
20 views

Why do people tend to stand on one leg when standing? [on hold]

I noticed that I and other people tend to stand on one leg when standing still (like birds do). Why is that?
2
votes
1answer
27 views

How many rounds of TCA Cycle would a complete oxidation of a triacyl(15-Carbon fatty acid)-glycerol, give?

This was a trickier question on a previous test, and I'm still not sure why, but the answer was "at least four". I answered "more than 22" and got it marked wrong. I assume that each fatty acid chain ...
0
votes
0answers
18 views

Are Water Bears powered by a cellular motor?

The following video https://youtu.be/aHsVyb_VfeA shows a Water Bear (https://en.wikipedia.org/wiki/Tardigrade) under the microscope. Starting from minute 1:30 it is possible to appreciate the inner ...
0
votes
1answer
18 views

Cell division - meiosis

Really confused. How many chromosomes pairs do humans have in their sex cells? How many single chromosomes do humans have in their sex cells?
2
votes
0answers
8 views

Extiction of non-mammal Synapsida

I am following M.J. Benton's Vertebrate Palaeontology, which explains how many groups of Synapsida were already extinct in the Mesozoic Era, with one obvious exception being the group of Cynodontia, ...
0
votes
0answers
8 views

Are cells constantly recycled in major parts of body?

I already had similar question about atoms: Are all body atoms really recycled several times during a life? Now I would like to know about cell level. Are cells constantly divide and die in all ...
0
votes
0answers
45 views

What is the Ramachandran z-score of a denatured protein?

I thought it should be 0, but the professor pointed out I was wrong. What should the Ramachandran z-score of a denatured protein be?
1
vote
0answers
12 views

Why human hair is losing its color over time? [duplicate]

Human hair is losing its color over time, that's a known fact. I would like to know why, meaning what biological processes are involved in this? Also, is it part of the DNA somehow, i.e. the exact ...
0
votes
0answers
16 views

Plants and thermal cameras?

I was wondering has there been any work done with plants and thermal cameras? I know in humans inflammation shows up as a warm spot using a thermal camera. Do plants have a similar effect? If so ...
1
vote
2answers
85 views

What Effect would Cannabinoids have on the Acute Porphyrias?

I should be clear in saying that this question is NOT intended for personal medical advice. Rather what I am looking for is journal articles and/or books that touch on this subject because I think it ...
0
votes
2answers
37 views

Geographical distribution of malaria and tuberculosis

Unlike malaria, tuberculosis (TB) is found across the whole world. Why and explain? I mean why are people affected with TB more than malaria and some say that in cold and developed countries malaria ...
3
votes
2answers
25 views

Exponential growth equation and bacteria

I'm a microbiologist, but I'm teaching some ecology in my intro-level course, so when we got to population growth, I thought I'd use the example of a microbial population. But, I hit a strange problem ...
0
votes
0answers
14 views

Cells of Zona pellucida

My textbook states: Blastocyst hatches out by lysis of Zona pellucida with the help of the enzyme strypsin, Later the cells of Zona pellucida gradually disappear. We know that Zona pellucida is ...
-1
votes
0answers
12 views

What is the difference between a hormone and a drug?

This question is based primarily on definitions. A common dictionary definition is that a drug is: any substance other than food, that when inhaled, injected, smoked, consumed, absorbed via a ...
0
votes
0answers
15 views

Why do birds in this time of year start singing so early?

I noticed that birds in the beginning of may start singing very early. Earlier than in other months. Why would this be?
0
votes
0answers
24 views

Chemical colouration and carotenoids [on hold]

How does Carotenoids obtained from diet become an important part of chemical colouration in animals?- What happens after carotenoids enter the body through diet till they cause body colouration? Some ...
2
votes
1answer
16 views

Moth with silver marking on wings

This is a moth that we found on a curtain inside the house a couple of days ago. Unfortunately, these pictures did not come out as well as I thought before I realized it outside. But I was struck my ...
0
votes
1answer
18 views

Why is chronic lymphocytic leukemia (CLL) most common leukemia in the West but so rare in Asia?

In "Advances in Chronic Lymphocytic Leukemia" (2013, Edited by Sami Malek), several times it is stated that CLL is very common in Western countries. However, it is quite rare in Asia. (I do not have ...
2
votes
0answers
18 views

Does the edge effect promote biodiversity?

I define the edge effect as: A term used to describe what occurs at habitat boundaries where two bordering communities influence one another. My question is whether it generally leads to an increase ...
0
votes
0answers
4 views

Serological assays measuring antibody response

Given that an appropriate immune response to a bacteria may be thwarted in an individual, including not producing all of the antibodies which are known to occur in people who have been infected, or ...
0
votes
1answer
47 views

What does characterization mean in a genomics context?

"The resulting libraries of gene sequences allow CDC and other laboratories to compare the genes of currently circulating influenza viruses with the genes of older influenza viruses and viruses ...
38
votes
8answers
6k views

Why does evolution not make our life longer?

Why does evolution not make life longer for humans or any other species? Wouldn't evolution favour a long life?
1
vote
1answer
16 views

Are there any (chemical) processes occuring inside a seed while it's in a dormant state?

If a seed were in a glass jar without a chance of germination, are there any (chemical) processes occurring inside the seed while it sits there? My intuition tells me no since my understanding of ...
0
votes
0answers
6 views

What did William Harvey discover from experimenting with deer?

On his wikipedia page, I read the following: In particular, Charles' hunting expeditions gave Harvey access to many deer carcasses; it was upon them that Harvey made many observations and ...
-1
votes
0answers
33 views

Why do electrophoresis gel boxes only have 1d wire electrodes and not a 2d 'mesh' as used in clarity?

Since the DNA and protein are electrophoresed in a 2D plane (along one dimension, the length of the gel), I am surprised that a 1D wire electrode is used for anode and cathode, and not a 2D mesh-like ...
-2
votes
0answers
67 views

Why does fart temperature vary? What's the hottest fart ever recorded? [on hold]

I read somewhere that the average fart temperature is equal to the average human body temperature: 98.6 degrees Fahrenheit. Sometimes I experience hot farts, while other times my farts are like a ...
1
vote
1answer
28 views

Are ribosomes assembled in rough ER and Golgi body, or in the nucleolus?

I mean all the components, such as ribosomal RNA (rRNA) are synthesized in the nucleolus, but is the whole ribosome structure assembled in the nucleolus or is it also done in the rough endoplasmic ...
0
votes
0answers
27 views

Rate of diffusion

I need to find out the intial diffusion rate across membrane. I know the formula of J=DA(C1-C2) but i am confused about how to make the calculations I also know the following: 1) Na+ concentrations ...
0
votes
0answers
6 views

Is salivation decrease during sleep beneficial?

Papers [1, 2, 3] tell that a salivation decrease is not only unpleasant, but harmful for dental health. What cause that decrease? What is the reason for it and do animals have it? I guess it's a ...
0
votes
0answers
3 views

Where do I find the label, whether this file data corroborates to a healthy tissue or a cancerous one in TCGA data?

I downloaded the TCGA dataset for LUAD (Lung Cancer), I find each file with miRNA sequence data like readCount and parts per million value and their are around 123 samples. But where do I find the ...
15
votes
3answers
12k views

Can one die from pain?

Is it possible that a human or any other creature can die from pain? I googled and found different answers. Some articles say Yes while others say No.
0
votes
0answers
9 views

About Hermaphrodite Mitochondrial Inheritance

From the textbook I've learnt that in general mitochondria are inherited maternally. However if the cross is between hermaphrodites (e.g. in C.elegans), where, in most cases, then should the ...
0
votes
0answers
13 views

What is the most important factors that affect our taste?

What ist the most important factor that affects our taste? our mood? (such like GERD) our genes? (more mascular people will need more protein) the food we ate recently? (to choose more diverse ...
1
vote
0answers
52 views

Does reproduction cause aging ? Is aging just a strategy to increase reproductive success in all organisms? [on hold]

Background for why I am asking this: I read a book—modern biological theory and experiments on celibacy— which uses life history theory to imply that reproduction is the reason why organisms grow ...
3
votes
0answers
31 views

Did the Great Oxygenation Event also cause a mass extinction?

Its usually assumed that the Great Oxidation Event around 2.3 bya caused a great extinction of anaerobic life on earth. But as I was reading Nick Lane's book, ...
0
votes
0answers
10 views

Pressure produced by blowing with mouth

I need some figures on the pressure humans are capable blowing with their mouth with zero flow. I only need very approximate figures. I'm guessing around 500mm of water? I haven't got a tube handy to ...
1
vote
1answer
95 views

Is metastatic cancer always lethal if uncured?

Can matastases spread in different parts of the body of an animal suffering from cancer grow in a limited way, such as not to cause much more harm that a benignant tumor in those parts of the body ...
0
votes
0answers
11 views

How can I apply any machine learning model/classifier on miRNA seq data?

I recently got micro RNA sequencing data from the TCGA. I am currently trying to early detect Mesothelioma. How is microRNA seq data different from microRNA expression data? MicroRNA expression ...
11
votes
1answer
309 views

What is the transmembrane 'Positive-Inside Rule' nowadays? Has the definition changed over time?

First definition. Two publications by von Heijne in 1989 and 1992 coined the 'Positive-Inside rule' and showed it's practical value in topology prediction of transmembrane helices. It was clearly ...
1
vote
1answer
16 views

A question regarding trichomes in plants

Trichomes in general are features of xerophytic leaves, which reduce water loss by evaporation by trapping water vapor and increasing humidity (as a result lowering the water potential gradient). BUT ...

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