All Questions

4
votes
1answer
73 views

Why does max heart rate decrease with age?

I have heard that max heart rate declines steadily with age, and can be approximated by the equation Max Rate = 220 - Age. What is the physiological reason for this decline, and how is it ...
2
votes
1answer
45 views

Which of the following demonstrates the pattern of development in Greylag Geese?

Which of the following demonstrates the pattern of development in Greylag Geese? {Please give specific answers, which among the following gives the best available demonstration?, If needed, have a ...
2
votes
1answer
95 views

What Aquatic Mammal has no Tail?

Found in a waterway in Butte County, CA. First thought it was a beaver kit, but it has no tail. What aquatic mammal has no tail?
2
votes
1answer
95 views

Is it possible to get infected with HIV from old blood?

Let's say that someone uses a needle which has some old blood infected with HIV. In this case, is it possible for them to get infected with HIV?
1
vote
2answers
139 views

On evolution statistics [closed]

This basic evolution theory question has been haunting me since childhood and I'm kind of embarrassed that I can't explain it yet: Consider a butterfly. It's wings have evolved to look like the eyes ...
0
votes
1answer
58 views

can psychology of a person alter his immune system and health?

I just want to know that can psychology of a moderate aged person alter his immune health? because I have read many a times about the different types of linkages between nervous system and immune ...
5
votes
3answers
263 views

Is there an 'anti-virus'?

A virus spreads around and usually attaches itself to the host, multiplies & causes diseases. But is there something like an anti-virus? A single celled entity that does the opposite: spreads ...
5
votes
2answers
92 views

What's the smallest organism that can produce voice?

What's the smallest organism (animal, insect, or any living creature) that can produce voice. And not just make sound, but has an organ to specifically to create sound, like how us mamals have vocal ...
0
votes
0answers
12 views

Cell volumes of the MDCK, COS1 and ECV standard cell lines?

Where can I find information regarding their volumes? In general where can I find information regarding common cell types?
2
votes
1answer
171 views

How do some plants grow in salt water, while others die?

My question is basically out of curiosity and comes from observing how certain plants (such as mangroves or salt cedar) can grow in seawater. If this gives the plant an advantage, why haven't all ...
-2
votes
1answer
33 views

What is the smallest known organism with a skeleton? [closed]

See question title. After doing some looking around on my own I haven't found much so I figured I'd ask some experts.
1
vote
2answers
435 views

Which organs do cats not eat on their prey?

My female cat is a very active hunter and brings me her prey daily. Except for shrews and birds, she always eats them entirely. This afternoon she brought me this: It was quite large (maybe ...
2
votes
0answers
35 views

How can cells produce antibodies despite error-checking mechanisms in their genomes?

How can immune cells produce so many different kinds of antibodies with different variable regions if there are so many mechanisms inside the cells that try to keep the DNA sequence as constant as ...
0
votes
2answers
32 views

How to find a PDB structure of a protease with a peptide like inhibitor

I wonder how, for purposes of just illustrating some concepts like substrate alignment in the catalytic triad active site, I can quickly and efficiently find a protease structure (irrelevant of what ...
1
vote
0answers
20 views

Are there critical points in ecosystems?

Some days ago, I was thinking (partially) about the complex balance that is needed for an ecosystem to exist. I got curious about the existence of some sort of critical point, something - that when ...
3
votes
3answers
60 views

what are good sources of free-to-use images and diagrams

I am looking for good image repositories for biology teaching. Photos and textbook-like diagrams. I am interested in images that can be used commercially without payment, or, at least, that require ...
0
votes
0answers
104 views

Ribosomal Turing Machines, DNA/RNA computation

I'm a computer science guy, recently crossing over to do some research in computational biology on RNA secondary structure prediction. While looking through the materials I got a crazy idea, what if ...
3
votes
0answers
46 views

Are small CO₂ concentrations devastating to certain cognitive tasks?

A new study shows strong effects of what should be a negligible CO2 concentration. The paper "Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making ...
1
vote
1answer
277 views

Carbon Monoxide and High-Oxygen-Affinity Varieties of Hemoglobin

I recently learned about the concept of "affinity" in regards to hemoglobin. For hemoglobin in humans, carbon dioxide has a lower affinity than oxygen, which allows gas exchange to occur in our lungs. ...
1
vote
2answers
395 views

Is epimysium same as fascia?

I have read that epimysium is dense regular connective tissue made covering the a muscle like bicep brachi. at the same time we have fascia that is made of dense regular tissue and covers muscles. so ...
5
votes
1answer
103 views

Which part of human eyes is getting tired?

It's a thing of common sense that if you read, drive or look at computer screen for too long your eyes will get tired. They burn, itch and try to close all the time. But I was wondering which part(s) ...
2
votes
2answers
51 views

TB disease - treatment and infection

Background: I'm currently performing research in mathematical biology, specifically on the treatment dynamics of HIV and TB co-infection. Question: Can a person infected with TB disease, who are ...
3
votes
2answers
140 views

How is information sent from limbs to the brain exactly?

Say you have a needle, and you poke a very specific area on your left thumb. A signal gets sent from that nerve up your spine and into your brain. How does the brain know exactly where this signal ...
2
votes
2answers
96 views

What is doubling of genetic material invented in flowering plants?

David Attenborough in his Kingdom of Plants 3D said, that flowering plants made two inventions: (1) doubling of genetic material and (2) symbiosis with animals. What was meant by "doubling of genetic ...
3
votes
1answer
69 views

What's the difference between diuretic veggies and alcohol that make the latter bad?

So I'm reading this article to Treat Fluid Retention and it suggests Eat foods with diuretic properties. But also Avoid drinks that will dehydrate the body such as tea, coffee and alcohol. ...
0
votes
1answer
26 views

Ion Channel gating

I have been studying ion channels and there is one thing i am confused about, gating between open and closed states in channels. Am i right in thinking gating is so fast that it is effectively always ...
2
votes
1answer
54 views

Could an annual plant be genetically modified to be a perennial?

My chives, asparagus, oregano, and rhubarb come back every year like clockwork. Suppose I want my bok choy to join the party - is there an "I'll be seeing you next year!" gene that can be modified to ...
2
votes
0answers
57 views

Is WIFI safe for humans? [closed]

I have wifi on at my home almost all the time. I learned that the frequency of visible light is around several hundreds of THz, while the frequency of wifi is only several GHz, which is only ...
2
votes
1answer
58 views

Source of hydrogen in reduction of oxygen in electron transport?

What's the source of hydrogen in the reduction of oxygen to water in metabolism? Is this implying that half the hydrogen comes from NADH and the other half from lone protons?
3
votes
1answer
37 views

Thrombus and Embolii

Can treatment of thrombus cause embolism, in case of very high blood pressure, that may even lead to a heart attack ? As the very high Blood pressure may cause some of the enzymes not act completely ...
3
votes
1answer
58 views

How Behind is the Human Mind (Latency of the Senses)

I would like to know if there is any research into the latency of human perception. Particulary: What is the minimum time for various inputs (vision, touch, sound) to be recognized by the conscious ...
3
votes
1answer
267 views

Where do butterflies sleep?

Do butterflies (insects) sleep, and if so, where?? I have googled for information but didn't get an exact answer.
0
votes
0answers
27 views

Reusable microarray chips

Microarray chips allow us to conduct many expression experiments in parallel to each other but they can be used only once as far as i know. Are there reusable microarray chips? Have people ever tried ...
6
votes
1answer
230 views

what is the difference between “cistron” and “gene”

I'm asking after reading the cognate wikipedia.en article on "cistron". I still am not sure about the difference of the two terms. To me it seems valid to picture a "cistron" as the genome wide set ...
2
votes
1answer
39 views

Quantitative Comparisons of Phylogenetic trees

I am working on a broad phylogenomic analysis of proteins involved in one particular cellular process. I have constructed a phylogenetic tree for each protein. I am now working on comparing those ...
4
votes
1answer
79 views

Blosum matrix with probabilities instead of the positive and negative scores

I am trying to find a version of the BLOSUM matrix that has the frequencies instead of the scaled log-odds. i.e. instead of the common version that tells us that the score LEU/ASP is -4, I would like ...
0
votes
1answer
100 views

Are harmful gases abiotic or biotic factors in our environment?

As we all know, harmful gases play a negative role in our society and our environment. Are these gases playing as abiotic or biotic factors in our lives?
1
vote
1answer
76 views

Simultaneously using both hands - How does that work?

Is some part in one hemisphere the decision maker and "calling the shots" - controlling the opposite side's hand "directly" and controlling its own side's hand through the corpus callosum. Or: is ...
0
votes
0answers
42 views

What is the effective line detected by ML II channel in ECG?

I want to find the approximate effective path/line on the heart that ML II channel detects on the heart. The normal ECG angle is 59 angle. ML II channel, which is a combination of two bipolar leads, ...
2
votes
1answer
65 views

Identifying a spider from my childhood memory

Once, as a child, I found a spider in my parents' garden. I remember catching it in a jar because I thought it looked unusual, but I never figured out what kind of spider it was and unfortunately ...
2
votes
1answer
431 views

Ancestral Allele explanation

I'm having some trouble understanding the concept of ancestral allele. What exactly does it mean? What does it have to do with Identity by descent/state? What does it have to do(if anything) with ...
2
votes
0answers
34 views

Questions regarding Scapulohumeral Rhythm

I'm actually an artist, but I wanted to ask this because it will help a lot in my figure drawings. My artistic anatomy teacher taught me about the Scapulohumeral Rhythm. He said that in during the ...
3
votes
1answer
76 views

Should the sum of RPKMs be constant over experiments

I have cufflinks data from 18 different RNA-seq experiments. I've noticed that if the sum all the RPKM values for a particular experiment, are vastly different between experiments. How could this be? ...
2
votes
1answer
32 views

Muscle force/energy relationship

I found the Hill muscle model, which helps relate the force a muscle can generate to its change in length over time (its "contraction velocity"). Is there a similar model to get an idea of the energy ...
1
vote
1answer
68 views

What I can do in order to improve the folding of the protein?

I am struggling with the expression of the certain protein. It seems that it is not properly folded and thus, it is not active. I tried to express it at the lower temperature and for the longer time, ...
0
votes
1answer
64 views

Pedigree analysis : autosomal or mitochondrial

I have tried a to decide if this is a autosomal dominant, recessive or a mitochondrial disorder. Is it possible to know for sure, or do you have to use probability? (English is not my native ...
0
votes
1answer
40 views

Can lymph be in peripheral blood?

I read an argument that 1-3% of lymph is in peripheral blood. However, I am not sure if this lymph is about lymphocytes in peripheral blood; not lymph itself. Lymph gets exchanged between capillaries ...
2
votes
2answers
93 views

Understanding the Amino Acids

I'm having little trouble studying general relativity or quantum field theory, but remembering all the amino acids and being able to think about them is something that's completely, utterly and ...
2
votes
0answers
33 views

dbSNP database table desciptions

I am trying to build a local implementation of dbSNP. I would like to know the descriptions of tables listed on ftp://ftp.ncbi.nlm.nih.gov/snp/database/organism_data/human_9606 and on ...
2
votes
1answer
62 views

What is the scientific name of such a fungus?

Several days ago, in a bush I found the fungus as attached which is about 25cm in height and does not look like an edible mushroom: Any one has an idea of its scientific name and other details?

15 30 50 per page