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This tag is for questions about the general biological features of human beings (as opposed to the biology of non-humans).

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1answer
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Why do humans lose subcutaneous fat tissue with age?

Why exactly do humans lose subcutaneous fat tissue with age? It appears that we either lose fat cell volume or we might actually be losing the number of fat cells with age. One hypothesis is that as ...
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0answers
20 views

Is it possible to greatly reduce the number of car accidents and still save almost everybody who needs an organ transplant?

According to this petition, after somebody dies, their organs can save 8 lives but some people die waiting for an organ transplant and the problem could be solved by switching from an opt in system to ...
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1answer
46 views

Very frequent multiple births in humans

18th century Feodor Vassilyev is said to have had children by two wives, each of whom only ever had twins, triplets or quadruplets. His first wife has 16 sets of twins, 7 of triplets and 4 of quads; ...
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0answers
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Why glucose is not stored as it is and why it is stored as glycogen in liver? [on hold]

Is glucose stable? Or is there any other reason for glucose being not stored in liver
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2answers
72 views

Humans have Cannabinoid receptors. Does that mean we're meant to consume cannabis?

I know the answer is no. But what then explains the name of these receptors being specific to Cannabinoid found in cannabis? Aren't Cannabinoid receptors exclusive to Cannabinoid? Why are they named ...
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1answer
25 views

İrreversible dopamine antagonist vs. Dopamine agonist

Can a dopamine agonist reverse the effects of an irreversible dopamine antagonist?
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0answers
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1answer
46 views

Do XX chromosomes on females genetically carry one from the father and one from the mother?

If there are two X chromosomes in a female do the two genetically carry the father's genes and the mother's genes?
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0answers
70 views

Why do I see noise in total darkness?

When I am in a totally dark room, I see mostly white, soft, and still noise. Users in the comments have considered this phenomena to be a phosphene or visual snow. Edit: this is a duplicate.
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2answers
32 views

What is the chance a given gene will end up in a given gamete?

Let us say a somatic cell had a desired gene. This somatic cell was replicated during interphase so that it had two of the desired gene. It then underwent meiosis. My question then is, what is the ...
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3answers
29 views

why do we tighten out muscles against cold?

When I'm in shower and I want to open the cold water on myself suddenly I make my muscles so tight before I open the water and that helps so much in being able to handle the shock. Why does tightening ...
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1answer
37 views

Is that true that plant stem cells can be used in humans?

I was reading an article (which seems very fake to me) on sensitive topics, but there was one astonishing statement: Stem cells are obtained from certain plants that grow all over the world. Once ...
3
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1answer
37 views

Animals as organ donors and organ's life expectancy

Recent attempts to find reliable organ donors was using genetically-engineered (GE) pigs as heart donors. The pig's DNA is altered so that its tissues will appear identical to the patient's tissue and ...
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0answers
8 views

Why is serum ferritin elevated in Chronic disease anemia?

I've been searching the reason of this but I've been not able to find it.
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1answer
30 views

Is sperm sorting also a genetic selection method? [on hold]

Because the x or y chromosomes separate and have their own genes isn't sperm sorting also a genetic selection technique?
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0answers
16 views

Pressure on tympanic membrane

How much pressure can you create on the eardrum, if you press your ears torwards your head with your hands? For example water can create lots of pressure on the ear, if we dive too deep, but how much ...
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1answer
28 views

Is there a correlation between B12 deficiency and cardiovascular disease?

I've read in several health sites that state that high blood homocysteine, as well as low B12 intake, is not only correlated, but actually causes cardiovascular diseases. In order to verify those ...
2
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1answer
76 views

Are we evolving as fast as the oxygen is depleting?

How much oxygen saturation have we lost in the last 100 years? As oxygen levels dwindle and industry, deforestation, and population increases, at what year and saturation will the low levels of ...
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0answers
20 views

Are mosquitoes actually louder than similar flying insects, or have we evolved to hear them?

I've come across many flying insects smaller than the common housefly, but (anecdotally) the only such species that I can hear from an appreciable distance away is the mosquito, with its distinctive ...
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0answers
22 views

Can foxglove glycosides enter human body via skin? [on hold]

I have replanted around 30 foxglove seedlings from a relatively small container, without using any gloves. The content of the pot was basically a clod of interleaved foxglove roots. Several minutes ...
1
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1answer
36 views

Why should collected blood from patients be analyzed as soon as possible?

I'm looking for the possible factors influencing blood samples. What happens to the blood cells esp. WBCs/PBMCs after 8 hours of blood draw? For example, I know that granulocytes may cause oxidative ...
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1answer
29 views

What happens to those who lay down or sleep on their stomach? Because, I heard it is harmful do this [on hold]

I’m asking this because, I heard from this video, that when you lay down on your stomach, it causes a lot of harm to your body. I want to understand, while sleeping or laying down on your stomach, ...
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0answers
54 views

What is the occipital bun, precisely (in Neanderthals and Homo Sapiens)?

I've read that the occipital bun is an anatomical feature of the Neanderthals, and only because modern humans (except sub-Saharan Africans) carry a few percent of Neanderthal DNA due to ...
1
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1answer
17 views

Viral susceptiility of Nose and eyes

I read that opening in our face like nose and eyes are one which get us infected with numerous communicable diseases like cold , flu ebola etc. Both these organs have preventive mechanism like nose ...
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3answers
2k views

Are red blood cells prokaryotic?

After searching "do antibiotics impact the immune system" I found out that antibiotics target prokaryotic cells. It all made a lot of sense thinking about all those yogurt recommendations you get ...
2
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1answer
87 views

Is marriage with half-cousin's daughter more risky than marriage with others?

I want to know is marriage with half-cousin's girl more risky than marriage with a non-family girl? Also I like to know if her parent are cousins(but from mother side), does it add more risk to this ...
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0answers
26 views

How to understand histology [on hold]

I'm starting to study histology and I'm finding it kind boring. I began with epitelial tissue, and there are several types of it which relates to a part of the body. But I dont understand it, I dont ...
3
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1answer
33 views

What would the RBCs of someone heterozygous for sickle cell anemia look like?

Would half of the RBCs look normal, and the other half sickled? Or would all of the RBCs have slight deformation/sickling? Thanks!
2
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1answer
46 views

Why there is no vaccine against Human Immunodeficiency Virus (HIV)? [duplicate]

I was informed by my teacher that this retrovirus changes its RNA, so there is not a drug which can recognize the RNA and somehow inactivates it. Are there any other reasons explaining why there isn't ...
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0answers
26 views

What if the luminosity of Sunlight increased by 10%

If the luminosity of sunlight increased by 10%, would people be able to survive outside? Would such brightness of light be very harmful to them, for exemple as much as the Mercury Vapour Lamp deprived ...
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1answer
118 views

Why are only few cigarette smokers prone to cancer?

It's tacit that only a few populace of smokers get cancer. What spares the others from it or what specifically cause cancer in those populace? See this Washington Post Article
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0answers
47 views

Why do people have characteristic body odour?

I am informed that odour (specifically coming from armpits) is due to bacteria residing on the skin do the work of manufacturing the malodorous compounds. So why do people have characteristic body ...
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2answers
36 views

How does 2,3 biphosphoglycerate works to release oxygen bound to the hemoglobin?

I read on Wikipedia that 2,3 BPG binds with the deoxygenated state of hemoglobin and helps in stabilizing it. It was also written that it helps release remaining oxygen from the hemoglobin. How? ...
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1answer
27 views

Frequent urination caused by sound of running water

I urinate at sound of running water when I brush my teeth or wash my hands . This only happens when I am home
2
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1answer
31 views

Why ketoacidosis is less common in patients of Noninsulin Dependent Diabetes Mellitus?

The other day my teacher said ketone bodies are mostly formed when insulin is less and NIDDM type diabetes mellitus has less chances to grow ketosis. https://medlineplus.gov/ency/article/000320.htm P. ...
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1answer
35 views

Why do alpha-gal allergies only occur after a tick bite if alpha-gal is already present in red meat?

I just read an NPR article about allergies to red meat being caused by tick bites. That stood out to me because I thought allergies are triggered by an initial exposure to some allergen. In this case, ...
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1answer
29 views

Neuroscience - A neuron with two types of synapses (electrical and chemical) at the same time

I learn that the nerves from the Peripheral Nervous System can carry signals from and to other organs of the body. I'm wondering if A Single Nerve carries 1) Only chemical signals 2) Only physical ...
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0answers
46 views

A human lifespan [duplicate]

Recently, I read an article that said a human lifespan does not have any limit and when a man turns 105 he has a 50/50 chance to survive another year. Some scientists say that a man who will reach the ...
3
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1answer
44 views

Is there a specific suffix for “with in a cell”? i.e. in a similar manner to how -aemia refers to within the blood

Words like hyperglycemia, hyponatremia, refer to the relative level of that component in the blood, not in the cell, is there a specific suffix for within the cell? I would like one word as an ...
2
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1answer
21 views

How does LDL leave the circulatory system and enter the interstitial fluid to deliver cholesterol to cells?

I have read that small molecules like oxygen and carbon dioxide diffuse through the capillaries, but larger structures can't fit through. This answer indicates that some proteins go through via ...
4
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1answer
53 views

Why is the hippocampus considered to be a cortical structure but not the amygdala?

I'm having some trouble understanding the anatomical differences that classify the hippocampus as a cortical structure but not the amygdala. I have included the screenshot of a diagram from Gray's ...
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0answers
29 views

What does it mean that growth plates are morphologically not equal but histologically are so?

I'm reading a text, and here it is written that epiphyseal plates / growth plates are morphologically not equal but histologically? Shouldn't it be the other way around?
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1answer
51 views

Mechanism by which hypokalemia reduces insulin secretion

Is there any known mechanism by which hypokalemia reduces insulin secretion? This video explains a mechanism, but its inherently wrong because ATP dependent K+ channels will allow movement of K+ from ...
0
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1answer
68 views

Why is exercise good? [closed]

The fact that exercise is healthy is a bit counter intuitive to me. If we have any machine, a car for example, the less we use it the longer it lasts. Then how is it that using our body to do sports, ...
2
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1answer
32 views

Can toilet or sewage aerosol transfer eggs of human parasites?

Flushing a toilet produces hundreds of thousands of tiny droplets containing viruses and bacteria (source): Up to 145,000 droplets were produced per flush, with the high-energy flushometer ...
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1answer
43 views

Spermatogenesis question

I found this diagram in my textbook regarding the process of spermatogenesis. But, I doubt if the labelling done is correct or not. Especially, I can't figure out any difference between the cells ...
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0answers
20 views

Does adenylate cyclase stimulate or inhibit acid secretion in the stomach?

I am confused about my teacher's notes. "Acid secretion is stimulated by ACh, gastrin and histamine. Histamine stimulates adenylate cyclase which increases cAMP production." When I looked this up ...
1
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1answer
26 views

Polar renal scarring in pyelonephritis?

Why does infection and scarring occurs at poles in Vesicoureteric reflux but not in Obstructive pyelonephritis? It is said in Robbins that, it is due to polar papillae being flattened or concave ...
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0answers
35 views

What causes dreams to happen?

I've heard that dreams can be influenced by what happens in our daily lives. There are many theories about why we dream, but no one knows for sure. Some researchers say dreams have no purpose or ...
4
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1answer
56 views

What exactly does Curare do to the peripheral nervous system?

so, I was told: If you give them the right dosage it'll wear off within an hour or two. It was used for veterinary stuff until they tried it on a human and realized it only paralyzed you and didn'...