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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2
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0answers
20 views

What is basis of centralization of “master glands” in the endocrine system?

I have just started reading about the endocrine system and I am having some difficulty understanding the basis of distribution of glands and associated hormones. I am using centralized to describe ...
-2
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2answers
37 views

Transfer by Ingestion [on hold]

Does our body absorb GM dna or Natural dna or dna of someone else's human blood(not relatives) taken with food so big that it has genes?
0
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1answer
42 views

At what saltiness will water simply pass through us?

If water has a low salt content, it hydrates us. When water has too high salt concentration, like sea water, it drains water out of us instead when we drink it. At what salt concentration would water ...
-1
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0answers
33 views

What biology should be known by a newly married couple? [on hold]

What is the minimum useful biology that a couple entering married life must know? I guess the knowledge must pertain to a basic understanding of the nature of reproductive system and use of ...
2
votes
1answer
91 views

Why do some people burn and others tan?

Connected to What is happening when we get a tan? - Why do some people burn while other people tan? Very pale people tend to just burn while other people tan very nicely, what causes this difference? ...
10
votes
3answers
2k views

What is happening when we get a tan?

Almost everyone nowadays wants that nice summer tan, but what exactly is going on beneath the skin? I've heard a few different theories about tanning - such as a tan is nothing but the pigmentation in ...
1
vote
2answers
116 views

What is a substance that is safe to eat, not absorbed and not metabolized?

I would like to know whether there are substances that are safe for humans to consume, are not absorbed and do not interact with any digestive process. So, food is disqualified because although it ...
2
votes
1answer
39 views

(How) Does the human digestive system process petroleum jelly, aka petrolatum?

Does the human digestive system processes petroleum jelly? In other words, does it pass through the digestive system without any interaction, or is it absorbed and/or metabolized?
-1
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0answers
48 views

Do I still have a chance of growing taller? [on hold]

I'm 20 and 5'6". My dad is 6' and my mom is 5'7". I don't believe I went through puberty abnormally early or late. My back molars still have not grown in, and my beard hasn't filled in completely (no ...
-2
votes
0answers
23 views

How hot can coffee be for it to burn the tongue? [duplicate]

How hot can coffee get before the tongue will get burned? I want to know an accurate temperature. Specifically coffee. I felt that the other question didn't have a definitive answer.
0
votes
0answers
32 views

How to resist the decreasing of your immunesystem after a cold shower? [on hold]

I have taken a couple of cold showers because I heard of the positive effects. I kindof like to take a cold shower now but I get the cold after I take them. After my first 5 cold showers or something ...
2
votes
1answer
31 views

Database of medically validated SNPs

I'm looking for all possible sources of clinically tested human SNPs. There is a handful of databases that store SNPs (like dbSNP), but I only need those that have validated presence/absence of ...
0
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0answers
25 views

Why do human have continuously-growing hair on their head? [duplicate]

Why do hair continuously grow on human heads, while the same doesn't happen on other parts of the human body? Where there are hair, they only usually grow to a fixed length; but they seem to have no ...
2
votes
1answer
42 views

What causes head hair to be different than body and face hair?

If you feel your head hair, it typically feels a lot softer and is easier to manage (comb, brush, fix) than a lot of other hair on your body - specifically I'm thinking about beard hair and pubic ...
4
votes
3answers
946 views

Why is wind cold for humans? [closed]

Coming out of the pool the other day, I felt very cold because I was wet and the wind picked up. My idea is that a "cold" feeling should be associated with low temperatures, but it's indeed wrong. ...
-2
votes
0answers
25 views

How many human cells will get affected at the prick of a pin? [closed]

Wikipedia states that there are 10^14 cells in a human body. My question is if I was to take a needle or a pin and pierce it just 2 mm in the body, how many cells will I be piercing? Thank you in ...
7
votes
1answer
312 views

How do female hormones cause blood to clot?

On most female-hormone supplements you get a warning that is something like this: The use of a combination hormonal contraceptives (CHC), like NuvaRing, is associated with increased risks of ...
6
votes
2answers
106 views

Which part of human body sustains most pressure when standing up straight?

Let's suppose a healthy fit barefoot young adult standing comfortably on a flat solid surface. A reasonable guess is somewhere around the foot. But is it the ankle, the heel, or the Metatarsus?
32
votes
5answers
3k views

Is there an advantage to antibacterial soap?

There are plenty of different hand soaps out there, as well as hand sanitizers. Is there an advantage to soaps that claim that they're antibacterial vs soaps that just say soap? In particular I'm ...
2
votes
1answer
81 views

What are dreams, biologically?

Falling asleep or states of subconsciousness does not stop the mind from making its own fictional images. These seem like sensations just like those received from human eyes. But, how do we define ...
2
votes
1answer
91 views

Does our heart stop when we sneeze?

Is it fact or myth that our heart stops beating for moments when we sneeze? If it is fact, what drives the heart to start beating again?
3
votes
1answer
61 views

What is the optimum length of abstinence for maximum ejaculation volume in humans?

There have been papers discussing this, and whether the abstinence period should be 1 week, 2 weeks or other [1, 2]. Some think the time to maximum ejaculation volume is even longer than this. doi: ...
9
votes
3answers
167 views

Why are the organs for reproduction and urinary excretion combined?

We eat food for getting energy to our body parts, and we excrete the wastes through urine, feces, and perspiration. Why has nature combined the urinary tract with the genital system (urogenital ...
11
votes
4answers
1k views

Will the heart keep beating if it is separated from the body?

The heart is a vital organ in our body, as it drives blood circulation. I was wondering if a heart keeps beating if it is separated from the body? If yes, then why?
3
votes
1answer
88 views

Do we need to drink less water in humid weather than in dry weather?

From my understanding, humid weather means that the air has a lot of water in it. Therefore, someone who lives in this kind of weather would be hydrating himself just by breathing. Does that mean ...
1
vote
0answers
35 views

Is there a comprehensive model of human attraction and sexuality? [closed]

I'm interested if modern (2015) biology has a comprehensive model of how human sexuality works. From my research, it appears that the drive for mating is primarily mediated by ...
5
votes
1answer
87 views

Can androgen-insensitive genetic-males get pregnant?

According to the linked report, people with androgen insensitivity syndrome appear as male, but have both feminine and masculine outer genitalia. However, I was not able to find out whether their ...
3
votes
1answer
120 views

Pigmentation in Jaundice

My textbook says that the yellow appearance of a jaundiced person is due to the accumulation of bile pigments in the skin. I am unable to understand why these pigments are not deposited in a healthy ...
4
votes
1answer
39 views

Is the autonomic nervous system only activated by internal stimuli?

My professor claims that the autonomic nervous system is only activated by stimuli from organs but I really feel like I've read that it can be activated by outside stimuli, although I'm not sure what ...
5
votes
1answer
556 views

Does inhaling glue (glue sniffing) reduce appetite?

I have heard from many homeless people that they sniff glue just to reduce appetite, as it comes cheap and is more affordable than actual food. Is this true, and if yes, why? This is totally opposite ...
10
votes
1answer
796 views

Do I not have any alleles from my mom's mom & my dad's dad?

So, I have an XX, & I got an X from my mom, & an X from my dad. My dad would have gotten his only X from his mother, & my mother could have gotten the X I got from her father or mother. ...
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0answers
17 views

Does Acromegaly cause actual expansion of the zygomatic(cheek) bone

Acromegaly is a disorder in adults involving excess growth hormone production. Since epiphyseal fusion has already taken place in most bones of adults , this does not cause an increase in stature. ...
1
vote
1answer
100 views

How much heat can a human sustain? [closed]

For how long can a human sustain a temperature of 180 degrees Fahrenheit (82oC) without damage in a confined place? For instance, suppose a person is sitting in a steam-filled room, without external ...
0
votes
1answer
34 views

X-recessive disorder pedigree confusing me

This is a pedigree of a family in which bleeder disease, an x-recessive disease, is present. I am asked which marker, A or B, the disease is linked to. I've asked about this type of problem before: ...
2
votes
1answer
19 views

Confused with gamete sorting problem

A man has the genotype AaBbCc, in other words he is heterozygous in three uncoupled loci on three different chromosomes. A, B and C are the dominant alleles while a, b and c are the recessive alleles. ...
0
votes
1answer
49 views

Why does our eyes got wet when we feel emotional or whenever we are hurt? [duplicate]

I was thinking like whenever when we feel emotional or whenever we got hurt we got tears from our eyes but why is that happen ? Why our eyes got wet ?
0
votes
1answer
18 views

Why can't this be 1st meiotic division non-disjunction as well?

The child has gotten 2 "sick" chromosomes from his dad and 1 healthy from his mom, leaving it with trisomy 13. I can see how this can happen in the second meiotic division of the father but I can ...
0
votes
2answers
25 views

Chromosomal translocation notation

A reciprocal translocation is denoted for example: t(4;12)(q32;q24) indicating that q32 on chromosome 4 being swapped with q24 on chromosome 12 if I understand this correctly. My question is: How do ...
0
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1answer
27 views

X-recessive disorders and genetic markers

Please observe the following pedigree of a family with a x-recessive disease (bleeder disease). The A's are genetic markers so close to the disease gene that recombination is negligible. I ...
1
vote
1answer
17 views

Is there a way to examine amount of red/white muscle fibers without biopsy?

I want to conduct some research on red and white muscle fibers, why do some people tire during certain movements while others do not. Obviously I can't get a biopsy on the subjects so I wanted to hear ...
-1
votes
1answer
36 views

Pedigree problem and type of inheritance [closed]

Please observe the following pedigree and come up with a conclusion as to which type of inheritance is most likely Now it should be obvious that it's either autosomal dominant or autosomal ...
3
votes
1answer
56 views

Walk me through microsatellite markers and PCR

Three polymorph microsatellite markers are used to try and narrow down the location of a disease locus, with the use of PCR with 2 flanks on each side of the actual polymorphic area. The PCR ...
3
votes
1answer
38 views

Gene frequency problem

1/330 of white people in south Africa have a disease called Porphyri. What is the frequency of the gene if it is inherited autosomal recessive? This one I understand. The genotype frequency is $q^2 ...
2
votes
0answers
37 views

Write the haplotypes of the family

I'm doing old exam assignments to prepare for my finals on Monday and I've stumbled on one assignment that I'm not sure how to tackle. A family with 2 children is examined for cataracts using PCR ...
1
vote
1answer
38 views

Dynamic mutation and huntington's

I read that Huntington's is a disorder caused by dynamic mutations in the DNA, which means that a triplet sequence of DNA changes from generation to generation. Say we have the sequence ATGATGATGATG. ...
3
votes
1answer
65 views

Do humans have skin cells that trigger oxytocin release in the brain?

I was reading an article by Montgomery on the therapeutic effect of pets (Boston Globe, January 12, 2015), and I found this quote: All animals appear to have cells directly under the skin that ...
4
votes
3answers
80 views

What is a genetic marker?

In DNA sequencing and analysis, what is a genetic marker? I've heard that microsatellites are genetic markers? Those are repetitive strands of bases such as GCAGCAGCAGCA etc. Why are they markers and ...
26
votes
2answers
5k views

What do ants do with our finger nails?

There is place in my house where I cut my nails. Here, there is an ant hole where an ant colony is seen. Whenever I cut my nails from here, they take my nails inside their hole. I was wondering what ...
5
votes
1answer
44 views

How do I know which alleles the parents have?

I have the following assignment where I am to look at the "tree" (not sure the english word) and assign whether or not they can be autosomal dominant or recessive as well whether they can be X-linked ...