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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4
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1answer
54 views

Are there testosterone receptors in female mammary tissue?

Does female mammary tissue have receptors for testosterone hormones? Do male hormones influence female mammary glands, as female hormones influenced the male mammary tissue, such as in gynecomastia? ...
0
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0answers
72 views

Is hypoxia/anoxia the ultimate cause of death?

I know there are different causes of death for humans like heart disease, cancer, stroke, injury and so on, but i was thinking if in every case in the last instance death is due to hypoxia/anoxia. ...
0
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1answer
116 views

Why do we have two eyes? [duplicate]

Humans, animals and birds all have two eyes. Why? In addition to why two instead of one, why aren't there more than two?
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0answers
22 views

is there a difference in meaning between the terms “bone architecture” and “bone structure”?

I'm wondering whether "bone architecture" and "bone structure" mean the same thing, or whether they refer to two different concepts. In this article - ...
6
votes
1answer
76 views

Is eradication of the Common Cold possible?

This is a thought experiment, but everywhere I've read seems to say that colds ALWAYS come from someone else. There's no mention of a cold arising in someone without it coming from another infected ...
0
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0answers
38 views

Life after decapitation? [duplicate]

I saw a video where an ant lost its head and was still walking for some time. If this is possible for an arthropod, what keeps it from working with a vertebrate? (Humans, especially)
1
vote
1answer
58 views

Genotype of children conceived after stem cell transplant?

If you have sickle cell disease and have a succesful stem cell or bone marrow transplant, your blood type changes to AA. But what about your future children? Do your sperm or egg cells continue to ...
0
votes
1answer
45 views

Can skin be removed and replaced so that it maintains its original cellular structure?

The cells in our body that form tissue, such as our skin, are interconnected. I would think that cutting out tissue or trying to repair/replace it, as is done in surgery, or after an injury, could not ...
1
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0answers
52 views

Why can't men produce milk, just like women? [duplicate]

This might seem a bit weird, but why can only women produce milk? Wouldn't it be more beneficial to our species if all humans could produce it? I can't think of any reason only one gender would need ...
0
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0answers
31 views

Why is alcohol purged from the body more slowly when we sleep?

It is a popular belief that when you get asleep after drinking alcohol, in the morning you have higher level in your blood than if you stayed awake the whole night. Is this true? If so, why? Is it ...
1
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1answer
36 views

Who and when was the first human diagnosed with hemophilia, or considered a carrier?

The earliest case I can find is Queen Victoria of England, who ruled from 1837-1901. Is this the first hemophilia case on record?
7
votes
1answer
347 views

What will happen if a foetus is Rh- and the mother is Rh+?

If a mother has Rh-negative blood and her foetus has Rh-positive blood it will result in rhesus incompatibility and lead to erythroblastosis fetalis. What will happen if the reverse occurs, when a ...
2
votes
1answer
40 views

Are all tastes just a combination of sour, sweet, bitter, etc.?

For example, can the taste of pineapple be isolated to just a certain amount of "salty-taste-triggering-molecules" and "sweet-taste-triggering-molecules" etc.? Can our current understanding of the ...
18
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2answers
2k views

Can Biologists identify all viruses?

I went to the doctor today with my girlfriend, and the doctor said that she had a virus but doesn't know which one and she should let the infection heal with some rest. The fact that the doctor ...
3
votes
2answers
107 views

Do humans contract more physical sicknesses and diseases than animals do? [duplicate]

I wondered: If I get into the library and look into the medical section it is evident that there are thousands and thousands of different human physical diseases. But if I look into the section of ...
1
vote
1answer
50 views

Breathing becomes harder in certain wind conditions

I'm not sure if this is the right site to ask this, but it seemed like the best option. I've observed on myself that, if I stand on a train platform and a cargo train drives by, creating strong, ...
4
votes
1answer
68 views

Why does a Urinary Tract Infection cause a strong, persistent urge to urinate?

There are plenty of articles on the fact the a urinary tract infection (UTI) causes frequent and urgent urination. For example; on this National Institutes of Health webpage. My question is: Why ...
-2
votes
1answer
190 views

How may the age of a child be estimated when required to do so, in video-graphic evidence?

How may it be possible to roughly conclude that a subject in a select piece of video-graphic evidence presented, is in fact a child, i.e. without the subject being, physically examined? Is it ...
2
votes
1answer
70 views

Reseach on feeling pain of other people

I'm more of a tech than bio kind of guy, but I have read and learned a lot alongside of my girlfriend's education. Which is very interesting!! Currently I want to investigate : people claiming to ...
4
votes
1answer
118 views

Why do you retch when you see something disgusting?

Why do you retch when you see something disgusting? I imagine it is some sort of evolutionary response, although I can't see the connection between receiving a signal that unhealthy conditions are in ...
5
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0answers
29 views

Can we predict a person's tolerance to cold exposure during excercise?

Being an amateur athlete and student of anatomy I've always wanted to know if there is a formula for determining an unconditioned body's tolerance to cold temperatures while exercising. I know the ...
1
vote
1answer
74 views

Which part of the reflex arc takes the longest time?

If the reflex arc is composed of 4 parts: Activation of sensory receptors, Conduction to and from the CNS, Transmission across the neuromuscular junction & Activation of the muscular contractile ...
0
votes
1answer
56 views

How body loses more fat in CO2 form than in sweating form? [closed]

Yesterday, I saw TV Game Show. There is question like this: Body loses more fat in which form? It gave 4 options: 1) CO2 2) sweating 3) xxx 4) xyz sorry i didn't remember 3 & 4 options. ...
3
votes
2answers
135 views

Can an argument be made that humans are 90% bacterial?

On the blog, All about Scientist in Microword: Microbiology, I read the post We are 90% bacteria, actually, which says that humans are 90% bacterial cells. If this is the case, then why don't we ...
5
votes
1answer
116 views

Colorblindness in females and random X chromosome inactivation

From Annenberg Learner: Because the X is inactivated randomly in cells, one cell could have the maternal X inactivated, while the adjacent cell could have the paternal X inactivated. This causes ...
0
votes
1answer
51 views

When does lactation occur?

High levels of estrogens and progesterone antagonize prolactin’s effect on the mammary glands, and it’s only after the placenta has been removed and the levels of estrogens and progesterone has ...
3
votes
2answers
122 views

Do intestinal flora have the same DNA as their host?

Please bear with me, this is not my professional field and I might be mixing things up. In an explanation why seeds won't start growing in one's intestines, the explanation given was that foreign ...
1
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1answer
64 views

Do vitamins protect you from common cold? [closed]

Do vitamins (taken as pills) boost your immune system, and make you less likely to contract diseases such as common cold or flu?
3
votes
1answer
229 views

Are there human-ingestible liquids that do not contain water?

My son asked me a question that stumped me: Is there anything a human can drink that does not contain water? It stemmed from a conversation in beverages in general where I was pointing out that they ...
3
votes
1answer
252 views

Why do humans masturbate? [closed]

Why does masturbating seem to be like an addiction? What controls or initiates the urge to masturbate? Is it good or bad or both and why is it so? I have heard guys who say that the do it ...
6
votes
1answer
625 views

Why does a fetus drinks and urinates into the amniotic fluid?

I was reading this website saying that fetuses urinate into the amniotic fluid. It also mentioned that, because we drink the amniotic fluid, we’ve been drinking our urine for months. However, why do ...
3
votes
1answer
66 views

Corpus luteum during the luteal phase and gonadotropins

Does the corpus luteum operate independently of the hypothalamic-hypophyseal-ovarian axis? I know that hCG sustains the corpus luteum in the absence of FSH and LH, but in an ovarian cycle where there ...
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0answers
46 views

Which sperm fertilizes the egg?

Hundreds of acrosomes must undergo exocytosis to digest holes in the zona pellucida. This is one case that does not bear out the adage, “The early bird catches the worm.” A sperm that comes along ...
0
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1answer
59 views

Acrosomal enzymes and the female reproductive tract

My textbook wrote that the reason why acrosomal enzymes are so securely contained within the sperm (thus needing capacitation to facilitate their release) is to prevent any premature release in the ...
2
votes
1answer
100 views

How does the pancreatic beta-cell know how much insulin to secrete in response to glucose?

How do $\ce\beta$-cells know how much glucose is in the blood? I know that when glucose enters a beta cell it triggers the cell to produce insulin. $\ce\beta$-cells trap glucose by converting it into ...
6
votes
2answers
330 views

Why can't our eyes smoothly transition from side to side without focusing on a moving object?

Why are we not able to slowly and smoothly look from side to side, or up and down in a single and smooth transition, given that we are able to do this if our eyes are focused on a moving object?
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0answers
46 views

Why exactly does a scarf help against a neck pain and a sore throat?

I was going out without a scarf and as this day my neck was more sensitive; after a while my voice was rasping, I needed to cough and my neck was hurting slightly. After coming home I put on my silk ...
-5
votes
1answer
153 views

Why are plants classified in living things? [closed]

@Volunteers Beware that I am none of the biological magnates. Nor a philosopher. This is just a sign of curiosity. And, I want only an intuition that enables me to see the difference. As far as I ...
0
votes
1answer
39 views

How DNA programs the first cell in womb into a human [closed]

Sorry if you see me silly. I am just a programmer happens to be curious about biology... So far I understand how DNA make protein, how cell divides, how one composed of cells->tissues-> organs. ...
0
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0answers
40 views

Why does histamine release in Type I hypersensitivity help in case of parasites?

The IgE system exists because the same events which lead to often-life threatening complications of allergy, in presence of parasites are helpful in their elimination. The tissue injury mediated ...
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0answers
24 views

Pathogenesis of type IV hypersensitivity

In hypersensitivity, as I understand it, a normal immune response gets excessive, misdirected or wrongly regulated to cause tissue injury. The various types determine the various ways in which the ...
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0answers
15 views

Where can I find epigenetics related microarray dataset for Alzheimer and Parkinson diseases?

In my thesis project, one of the tasks regards co-expression network analysis for epigenetics (methylation) data. In GEO and Array Express repositories, I have already searched for the microarray ...
-2
votes
1answer
70 views

After doing brush I feel hungry? [closed]

Why I feel hungry after brushing my teeth in morning? I usually have my dinner in between 9 to 10 at night and then I sleep at 12. Sometimes I wake up at 6 in morning and then I go to brush my teeth. ...
2
votes
1answer
34 views

How are cardiac cells stimulated by an action potential?

Why, and how, does the action potential of one cell in the heart stimulate an action potential in the next cell? I'm interested in an answer with citation.
3
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0answers
35 views

Why are kidney discard rates so high?

A recent report from UNOS states: The kidney discard rate has returned to pre-KAS levels, dropping from 20.2 percent in the first six months to 18.4 percent in months 7-10. To me, this seems ...
2
votes
2answers
94 views

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?
1
vote
1answer
30 views

How does increased heat increase the rate of metabolism?

I have heard that taking a hot shower helps blood circulation metabolism. For (2) metabolism, I think that the rate is increased since kinetic energy is given to compound to bond with enzymes ...
3
votes
0answers
18 views

What are necessary parameters for a tissue scaffold to be biodegradable?`

I am a mechanical engineer with little biological experience, but I have recently been looking at tissue scaffoldings. My current understanding is as follows, but may be flawed. I would appreciate ...
0
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0answers
27 views

Why doesn't EMG data for triceps show a clear relationship?

In a surface electromyography (EMG) experiment of the triceps muscle where a person lifts weights, I found the value for maximum amplitude of EMG signal to be rather similar for all loads of 0-10kg. ...
3
votes
2answers
47 views

What neurons make up the CNS?

I generally see it written that there are three types of neurons, classified by projection: (1) sensory neurons, (2) interneurons, and (3) motor neurons. Now, in the CNS, I don’t think there would be ...