183 Answered Questions for the topic human biology
Constant or variable number of chiasmata during recombination?
During recombination, is the number of chiasmata consistent for each gamete and are the chiasmata regions consistent within a single organism?
Why don't teeth glow?
Hydroxyapatite is the main component of tooth enamel. It contains phosphorus in the form of phosphates, pyrophosphates etc. that are found to exhibit the the property of phosphorescence. But why... more
Can humans eat grass?
Can a human eat grass and digest it? Could it be possible to use it as food just like other plants such as wheat or beans?
How did the cardiovascular system evolve?
How has evolution created our blood, lungs and the heart?We can't exist without blood, which transports the oxygen to all areas of our body. However, the blood needs a lung, which gives it the... more
Human evolution: Where *exactly* did the first human come from, whose parents were not?
Layman here. So I have never really quite understood this facet of human evolution, (or any other for that matter), in that, I understand the evolutionary process, but I get lost on the 'border'... more
How much time does it take for the naive T Cell to get activated?
Suppose a naive T cell comes in contact with an APC. How much time does it take for the T Cell to get activated and within how much time does the T cell move away from the APC due to... more
Why do Kupffer cells not attack malarial sporozoites?
During malaria, why don't Kupffer cells (hepatic macrophages) attack the _Plasmodium_ sporozoites and stop schizogony, thus saving us from the disease?
What is the molecular basis of hangovers?
Well, most of us have experienced the wonderful feeling of the dreaded hangover. How does it work exactly? I imagine it has something to do with dehydration but what are the underlying... more
What is our skin made up of?
Again, it is a basic question. What is our skin made up of? is it made up of many cells arranged in a systematic way or is it just like any layer say of a book?? what is the difference? where is... more
How do the pharmacodynamics of the NSAIDs differ and are there "resistant" COX phenotypes?
I know that the non-steroidal anti-inflammatory drugs (e.g., aspirin, ibuprofen, naproxen) affect the enzymes cyclooxygenase (types I and II).Is there any difference in the degree to which these... more
How is sebum secretion regulated?
The principle of homeostasis in biology says that living organisms try to maintain some sort of equilibrium. Doing that requires the use of feedback mechanisms to regulate things like temperature,... more
How do bile salts affect lipase activity?
**BACKGROUND**: It is well known that bile salts are needed for emulsification of fats. It is then said that this increases the surface area for activity of pancreatic lipase, implying that bile... more
Why do the humans become sleepy after meals?
I don't know about all the mankind, but I know enough people, who becomes sleepy after their meals. Also, I'm not sure, what kind of food do they consume, but I personally get sleepy almost from... more
Why does hair grow after trimming but remains at a constant length after a while?
Some hair especially body hair regrows after trimming but stops growing after a while. What is the mechanism behind control of hair growth and how is the length limit determined?
Why do I only breathe out of one nostril?
I was just sitting with my hand next to my nose and I realized that air was only coming out of the right nostril. Why is that? I would think I would use both, it seems much more efficient. Have I... more
What is the speed of blood?
The speed of blood may vary from one place to another and may be quite low in the tiniest vessels compared to the biggest one. What is the speed of blood while exiting a normal human heart?
Is monogamy a human innate behaviour?
As the question states, got curious and I was wondering if monogamy is an innate human behaviour or is it because of how we built society (religion, traditions, etc.)? Let's say we go back in time,... more
By what mechanism does Risperidone swell breast tissue?
There has been much talk of the anti-psychotic drug Rispeirdone causing un-natural breast tissue growth as well as galactorhea (milk production). Especially in young men and boys.What is the... more
How was the Huntington's disease gene's location found?
I read in the book "Why we get sick." by Nesse and Williams that:> Steady detective work and fabulous luck have enabled geneticists to> pinpoint the Huntington's gene on the short arm of... more
Why Does Salt Water Help Sore Throats?
I am having some trouble understanding how salt water, a simple solution, could so effectively remove the pains of a sore throat. I do believe that the answer is closely related to hypo/hyper-tonic... more
Do spinal cord reflexes (such as the knee-jerk reflex) continue to function under general anaesthesia?
The knee-jerk reflex is an example of a stretch reflex. Stretch reflexes are monosynaptic reflexes happening in the spinal cord without involvement of the brain.Does it mean that this reflex will... more
Can an adult without genetic lactase persistence still develop a tolerance for dairy foods?
While investigating the rise of adult lactose tolerance, I came across the news that China has been encouraging its citizens to drink more milk, even though most of the Asian population lacks the... more
Blood draw from the elderly or those with tiny veins?
A lot of people have very small veins making it next to impossible to draw blood. Would a nitroglycerin tablet (or some other vasodilator) before drawing blood help to enlarge veins?