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Questions tagged [human-biology]

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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Help on reconciling seemingly contradictory evidence about fetal experience

Fetal awareness and especially fetal pain are controversial, political issues. However, I do not wish to get into politics and want to merely stick to the scientific evidence. I have found statements ...
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2answers
48 views

Is the glomerular filtration rate, per kidney or for both?

We say in a healthy human being the average glomerular filtration rate is about 120 mL/min. Is that for both kidneys together (60+60), or just one kidney? Pardon me if this makes me sound like an ...
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1answer
78 views

Why can a zygote develop into all different types of cell, whereas a differentiated cell cannot? [closed]

A cell formed by the fertilization between two gametes has all the DNA and can lead the development of a human person (or other animals in other species). But other cells in a human person has also ...
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39 views

Which gene regulatory network is the largest in human?

What is the maximum number of nodes involved in any gene regulatory network and which network is it, provided its from human?
4
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1answer
76 views

What would be the fate of protein made from D-amino acids after ingestion by humans?

There are some natural peptides made of D-amino acids, rather than the L-amino acids normally found in nature. It is now possible to chemically synthesize artificial proteins made of D-amino acids. ...
2
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1answer
57 views

Why don't we find animal corpses and skeletons all throughout the woods?

Where in the forest do wild animals die? I rarely (occasionally, but rarely) come across animal bodies. Where are the large skeletons of bears and deer? Detectives often investigate human bodies ...
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1answer
44 views

What are some good biological tests you can do to yourself? [closed]

I would like to do things like study my own blood and DNA. What kind of things can one do at the present time that are fairly simple. Or require minimal equipment like a microscope? Are there some ...
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0answers
23 views

Exhaustion of skeletal muscle and ligaments

I read somewhere that while doing lifting back should be straight(means normal curve), so that erectors muscle in back do the work but it gets tired easily. Hence we form curve on our back like when ...
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0answers
18 views

Is it possible to get a XYY genotype by the first meiotic non-disjunction?

I have read that the cause of XYY-Syndrome is a non-disjuction in the secondary non-disjunction in the meiosis. I was woundering if it is possible to get the XYY-Syndrom by the first meiotic non-...
2
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1answer
50 views

does the amount of blood circulate in a body is same before and after amputation?

if a person loose his hand in an accident do the blood flows through his body is equal to the volume of blood before accident? how human body manage with that blood which is deserved by the missed ...
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0answers
35 views

Around what time did dark skin disappear from Europe?

As Europeans gradually became lighter skinned, there would have been people that still had dark skin. Around what time period did Europeans become completely light skinned?
2
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1answer
84 views

Why does drinking milk lead to increased fractures?

Milk has always been associated with strong bones due to the high amount of protein and calcium in it. Yet reading it up on wikipedia, A study published in The BMJ that followed more than 45,000 ...
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2answers
20k views

Many black people I've met have bigger lips than white people, why? [duplicate]

I noticed that many black-ish people I've met have bigger lips than the white-ish people I've met. However, not all black-ish people have big lips. Is there any explanations in terms of natural ...
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1answer
85 views

When was it understood that a male haemophilia sufferer can't pass it on to his sons?

Haemophilia A and B are both X-chromosome mutations, so a sufferer necessarily inherits the disease from his mother. She won't have serious symptoms unless both of her X chromosomes have the mutation, ...
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2answers
166 views

Why haven't humans evolved to fly? [duplicate]

Why haven't we evolved the ability to fly? I mean, it is advantageous when you take into account how many predators and parasites exist on the land, and there may be less or no dangers from birds up ...
4
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1answer
411 views

What does +60mm mean in MRI scans?

What do the -30 to +60mm markings mean in this MRI scan image?
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0answers
23 views

What metric(s) is a good proxy for relatedness?

In attempting to seed a simulation, where an individual foregoes resources that go r to same-type individuals and (1-r) to all members (including same-type individuals). What commonly used metrics ...
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1answer
83 views

Is cruelty a human instinct? [closed]

I had started studying human behaviour and human instincts a few months ago, earlier the question was raised after seeing human behaviour with animals (his prey). Animals hunt their prey for eating, ...
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0answers
155 views

What secretes the pericardial fluid that protects the heart from the contraction's friction?

As you guys know, the membrane that protect the heart is the pericardium, which consists of 1) The serous pericardium, which is divided into visceral pericardium and parietal pericardium, secretes ...
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1answer
44 views

Do B/T cells form from lymphoid tissue or bone marrow?

This website says lymphocytes are produced in bone marrow https://courses.washington.edu/conj/immune/lymphoid.htm But if that's true, then what cells do lymphoid tissues produce? It could make sense ...
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2answers
357 views

Where are eosinophils and basophils phagocytic?

It seems known that neutrophils circulate and are phagocytic within the blood stream, but I'm having trouble finding similar conconclusions about where eosinophils and basophils are phagocytic which ...
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0answers
26 views

Understanding hyper- vs hypokalemia

After searching the web for a while, I found that: Hypokalemia results in a prolonged Q-T wave interval Hyperkalemia results in a peaked T wave and a wide QRS complex Now, I'm trying to understand ...
3
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1answer
80 views

Which kind of electrical brain activity is associated with consciousness and why?

According to this article The ethical brain At the end of the week 5 into the 6 (42-43 days) the first electrical brain activity occurs in a pre-born developing human. And according to the same ...
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1answer
2k views

How do we sweat immediately after drinking water on a hot day?

On hot summer days, when I drink water to quench my thirst, my body immediately responds by sweating in 5 to 10 seconds or maybe less. How does our body detect the presence of water in the stomach so ...
2
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1answer
87 views

advantages of shivering in cold environments

When we feel cold, our the muscle tries to generate heat by shivering and the brown adipose tissue tries to generate heat by non-shivering methods. The muscle generates heat but also spends energy on ...
4
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1answer
53 views

How is mankind important to nature? [closed]

Like mosquito eggs are important for fish, what’s our role in balancing the life on earth or its ecosystem. Please suggest if this question doesn't fit in this community. I am a mechanical engineer ...
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1answer
165 views

Do reproductive organs function before puberty?

Testis means one of the two male reproductive glands that produce spermatozoa and secrete androgens. Ovary means one of usually two organs that produce oocytes and secrete oestrogen and progesterone. ...
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0answers
18 views

Is genetically given percent of fat stored under the skin higher for colder regions?

Is there a study on the dependence of the natural amount of subcutaneous fat and environment temperature? Is there a genetic difference in fat storing across human populations?
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1answer
77 views

Why trust vaccine statistics from the mid-20th century, if ELISA tests were not available and disease diagnoses were completely subjective? [closed]

Why trust vaccine statistics from the mid-20th century, if ELISA tests were not available and disease diagnoses were completely subjective? Any answer is helpful. Please let me know.
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3answers
160 views

Knockout and knockdown of gene

Out of curiosity, I got this question whether knocking out (deletion) of a gene on one side and knocking down (RNAi) of the same gene on the other side will affect the cell in a similar manner or not. ...
0
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1answer
21 views

What prevents platelets from clotting regular blood vessels?

Platelets clump together to initiate clotting, but, why don't platelets clot within healthy tissue and cause heart attacks all the time?
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0answers
142 views

Can hypertrophy of the temporalis muscle and masseter muscle widen the zygomatic process?

If one hypertrophies the masseter muscle and temporalis -- both muscle groups that run underneath the zygomatic process/arch bone that rests and makes up the side of the human face and connects to the ...
0
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1answer
362 views

Why do lips heal fast

Whenever I have any cut in my lips ,it gets healed in 2-3 days so why do lips get healed faster as compared to other body parts?
8
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1answer
478 views

Why can I raise my left eyebrow independently from the other but not the right?

I've seen the same question on other forums, but have not come across any definitive explanation. The non-cited answers seem to fit into three categories: It is due to greater muscle dexterity on ...
2
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1answer
206 views

To what extent is prion aggregation responsible for Alzheimer's disease?

I was intrigued by a description of prions as a factor regarding 'Mad Cow Disease', the epizootic threatening the cattle stock of the United Kingdom and France predominantly. Understandably, the ...
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2answers
87 views

Why are my calculations for O2 requirements of daily metabolism so far off?

When I attempt to calculate the O2 necessary for a day of metabolism at rest (for an imaginary average human) and compare it with the expected O2 consumed per day my results differ by a factor of 3. I ...
0
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1answer
39 views

Building microtubules [closed]

I have some questions regarding building microtubules: Do alpha and beta monomers always exist as dimers when they are bonding to form tubulin? When tubulin structure is destroyed, do alpha and beta ...
2
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2answers
134 views

Does human behaviour that is caused by inheritance depend on the environment and lifestyle in general?

Different breeds of common domesticated animals such as horses and dogs clearly show different behaviour, instincts, social relationships and similar, due to their biological inheritance. Still they ...
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1answer
63 views

Why do men have a greater chance of suffering from hair loss?

If we look around we'll find that men are more likely to suffer from hair loss when compared to women. Is there is any specific reason for this?
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0answers
120 views

Log2 vs Quantile normalization [closed]

I am learning normalizations, I wonder when log2 and quantile normalization is used in each situation, may I ask if there is any material that compare these two types especially in microarray ...
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0answers
151 views

Effect of Testesteron and Estrogen on adult opposite sex?

I know that if Estrogen is given to a teenage male then it triggers the development of secondary sexual characters of a female the male body, like breast growth and other. and similar happens if ...
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1answer
10k views

What would cause a single white eyelash?

I couldn't find a paper who could give me the explanation. Unfortunately, according to my search, it seems there are not many reported case, particularly for the younger population (<30). Would ...
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0answers
541 views

Can Wasps smell fear?

There are two conflicting things I have heard. One more anecdotal: Wasps can smell when you are afraid of them The other from reading popular science magacines: Humans don't produce any ...
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0answers
14 views

Can varied temperature while sleeping help quality of sleep?

I read an interesting article which is about relations between body temperature and quality of sleep. I'm interested in the phrase from the article. Other experiments that varied the ambient ...
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1answer
68 views

How does human life expectancy change with age?

Human life expectancy tends to be given as a single number reflecting age at death from birth. But life expectancy should really grow the longer you live, because, for example, once you hit your ...
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1answer
125 views

Can 2 people give rise to billions? Adam and Eve 2.0 [closed]

With with the advancement of GMOs the idea of giving rise to humans from 2 people is possible making questions like this invalid? How many people are required to maintain genetic diversity? With ...
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2answers
81 views

Are all of our hormones synthesized in the same gland that they are secreted from?

For example, growth hormone is secreted from the anterior pituitary; is it also synthesized there?
0
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1answer
26 views

What are some features that do not make an individual better than others without this feature? [closed]

If a mutation occurs so that this allele gives a noticeable feature that is present in this individual but absent in every other individual and this feature is of no benefit or detriment to the ...
2
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1answer
64 views

why is LPL (lipoprotein-lipase) down-regulated during fasting?

During fasting our body needs additional sources of energy and that's why triglycerides are broken down into fatty acids and glycerol. where fatty acids can be used to generate acetyl-coA and ...
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0answers
21 views

How many strands of Myosin Head is in a Myosin filament?

I am doing a research about sacromere in striated muscles, I read a paper (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3963759/ ) and it states the follow: "Rotational symmetry is defined by the ...