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).

Filter by
Sorted by
Tagged with
1
vote
1answer
53 views

What are cells not affected by hormones called?

Cells that are affected by hormones are called target cells which have their own receptors that listen to signals. I'm unsure of the actual name of cells that are not affected by hormones, I tried ...
1
vote
0answers
22 views

Do people have local immunity?

I mean the immunity that covers only one body part or skin area after exposure to the infection but does not cover the whole organism.
1
vote
0answers
55 views

Can two proteins activate/inhibit the same gene at the same time?

Suppose there are two proteins inhibiting a particular gene. Its not necessary that both will inhibit the gene at the same time instance right? So if one protein has already inhibited that gene before ...
0
votes
1answer
39 views

Does Japan have an ageing population? [closed]

I often hear Japan has a declining/ageing population. It seems to be the prime example for this kind of thought. Yet after moving to Japan and after having been there for travel several times already. ...
3
votes
2answers
105 views

Why do red muscle fibres have more mitochondria than white muscle fibre but less ATP than White muscle fibres?

This is a question given in my Anatomy book and I am really confused because logically the substance which have more mitochondria should have more ATP as mitochondria is the power house of cell.But ...
2
votes
1answer
62 views

Can a young voice have physical causes?

I have noticed that some older adults (40+ range) can have voices that sound much younger than their actual age (i.e. an adult sounds like an adolescent). My question is: could any physical aspects ...
0
votes
0answers
28 views

Brain evolution in the age of the caesarian

I have just been reading an account of the evolution of human intelligence in Matthew Syed’s recent book on diversity, called “Rebel Minds”. He is not the originator of this idea, but he suggests ...
0
votes
1answer
34 views

In human embryology, what starts ovum cell division?

Maybe I am not using the correct search keywords in Google, but I cannot seem to find anything beyond basic information taught in schools about fertilisation of the egg by the sperm. After the sperm ...
0
votes
0answers
22 views

Does any tendon in humans receive a high amount of blood supply? Or is the property of not receiving a large blood supply a constant across tendons?

I read on https://www.physiocomestoyou.co.uk/blog/all-you-need-to-know-about-tendons/ (mirror): [Tendons] do not have a large blood supply. Does any tendon in the human body receive a high amount ...
2
votes
1answer
138 views

Is sexual desire stronger in men than women?

Usually in popular culture it's considered men sexual desire is stronger than women. This seems to be congruent with the availability of sexual related items for men and women, such as magazines, ...
0
votes
1answer
450 views

What are the coverings of femoral hernia?

It was my Viva question and I was really puzzled.I know what is femoral hernia and it route like the abdominal content moves down the femoral canal and further through the saphenous opening and all ...
3
votes
1answer
105 views

Why do we need to amplify DNA sequences?

I am learning about biotechnology. I have no education in biology or chemistry and am simply interested in the subject of biotechnology. I am wondering why we need to have multiple copies of a piece ...
1
vote
1answer
142 views

Sleep deprivation relation to growth rate and mental health in adolescence

Do sleep deprivation and its timing affect growth rate and mental health in adolescents? If so how much sleep is enough for teenagers?
-1
votes
1answer
51 views

Why males are more prone to cardiovascular diseases such as heart attacks than females?

I often see more people of males undergoing treatment for heart disease. It is often said that female reproductive hormone (oestrogen) has some cardio-protective action by preventing constriction of ...
-1
votes
1answer
423 views

What happens if an enzyme stops working in the body?

For example, if the enzymes in the digestive system stop working will the digestion still occur as enzymes are only catalysts for the reactions. Thank You
2
votes
1answer
38 views

By what mechanism do our nerves lengthen as people get taller?

How do nerves get longer as kids grow taller? I searched for an answer but I can only find information on the formation of nerves in embryos.
0
votes
3answers
107 views

Are there any proteins not found in the brain that are affected by prions?

A prion is an abnormally folded protein that is capable of causing otherwise normal proteins to also misfold and become prions. They are responsible for causing diseases such as Kuru and Creutzfeldt–...
0
votes
0answers
53 views

Human femur maximum strength

In this video https://www.youtube.com/watch?v=os98s9kBlOI it is demonstrated that a moose leg bone can support until nearly 10 tonne before break. Is there any similar demonstration on human femurs? ...
1
vote
2answers
181 views

Why isn't life expectancy normally distributed?

Lots of phenomenon in nature can be plotted onto some sort of normal distribution, and that makes intuitive sense to me (such as human height). Why then, does global human life expectancy drop off so ...
1
vote
1answer
104 views

Are there any benefits/disadvantages/traits from having a permanent lower core temperature?

My body temperature as far as I remember has always been around 35.6 degrees Celsius, that's a degree less than what is the usually quoted as the average temperature for humans. Are there any known ...
1
vote
0answers
38 views

Does intelligence depend more on environment than on genetic factors? [duplicate]

Many have argued that the test of IQ is simply a test of language. The application of the test consists of asking a number of questions. The person should understand the question presented to them and ...
1
vote
0answers
39 views

How much Oxygen can the Human body carry?

Basically - the title: How much Oxygen does a human body carry at a single point? What have I tried: A friend of mine has done some calculations and came up with the following numbers. Neither of us ...
1
vote
0answers
43 views

Is it possible to buy a DNA sample with a specific mutation?

I would like to test a genotyping method (ARMS) on a specific human snp (heterozygous or homozygous ). Unfortunally, we do not have any dna samples with the mutation. Is it possible to buy somewhere a ...
5
votes
1answer
72 views

Can stress and arousal be independent?

I'm trying to figure out if it's possible to have a stress response without being initially, or simultaneously aroused. I'm defining stress to be physiological stress (ie. release of cortisol) and ...
1
vote
0answers
36 views

Could ions inside lungs produce hydroxyl?

I am not proficient in either biology or chemistry. However, I have a question which I can't find answer to. It seems to belong somewhere between chemistry and biology. I apologize for any errors and ...
1
vote
0answers
35 views

Can we “learn” reflexes?

Can we force our bodies to react to situations faster than our brain can think about them? Some reflexes I can think of off the top of my head: knee jerk reflex retracting hand when touching a hot ...
0
votes
1answer
71 views

Does the 1:1 sex ratio at birth apply to every human pregnancy or is it a statistical average?

Are there genetic factors that biase the sex ratio of offsprings for each person but average to 1:1 for the entire human population, or does the 1:1 ratio apply to every single fertile person?
2
votes
1answer
53 views

What do we mean by MHC molecule diversity? Does each human have a variety of MHC molecule isoforms?

I'm going to try and explain what I think I know From what I understand, MHC/HLA molecules present peptides to T cells. To be able to present peptides from a wide variety of pathogens, they need to ...
14
votes
2answers
2k views

Can UV radiation be safe for the skin?

It is well known that UV radiation can damage the DNA and generally harm our skin. We also know that UV radiation helps on the production of melanin and Vitamin D. From what I could find, the DNA ...
4
votes
1answer
130 views

Does body absorb nutrients less efficiently if we ingest the same amount at the same time, opposed to spreading over a larger period?

I would like to understand if ingesting a certain amount of nutrients will result in different absorption from my body, depending on whether I ingest that amount spread over time or everything at once....
1
vote
0answers
71 views

What are the sufficient criteria that make an entity a living homo sapiens? [closed]

When I say criteria I mean like x biological functions or y genetics. If it were to be appearance,anatomy. A corpse completely looks like a man. Moreover a person who has had their 4 limbs amputated, ...
1
vote
0answers
47 views

Why do I have 95% of chimpanzee's DNA, and only 2% of Neanderthal's DNA? [duplicate]

Excuse me if it is a question with a simply answer, but I don't understand these discoveries, looking a discrepancy from my unknowledge of genetics: I have 95% of Chimapanzee's DNA, and, I have [...
4
votes
2answers
109 views

What could humans do to “see” what dogs smell?

We're able to see a lot of things using computers that we can't see normally: yellow-green, UV light, X-rays, etc. What do we have that harnesses the ability to "see" what dogs smell (e.g., harnessing ...
0
votes
0answers
34 views

How does the cardiovascular system improve upon repeated, strenuous exercise?

New here, hopefully this is the right place to post this question. It's widely known that repeated, strenuous aerobic exercise gradually improves the capacity of one's cardiovascular system — $\text{...
1
vote
1answer
240 views

Are casein proteins in UHT milk digestable for infants or toddlers?

As a novice cheesemaker, I have read that Ultra High Temperature prosessed milk is unsuitable for cheesemaking, as casein proteins are denatured and cannot be curdled with rennet. I have verified that ...
-6
votes
1answer
113 views

What separates humans from other animals?

It is clear that humans are distinguished from the other species on Earth, but what specific features are the cause? Other animals like chimpanzees have been shown to have consciousness and some self-...
1
vote
0answers
48 views

Which chemokines are being produced by melanocytes?

I am looking into Vitiligo it's an autoimmune disease that results in apoptosis of melanocytes due to misfolded protein accumulation. It also dramatically increases breast cancer rates (600 times) ...
1
vote
1answer
48 views

Why can early embryos survive freezing?

According to this Blastocyst & Embryo Freezing in IVF Embryos can be frozen at the pronuclear stage (one cell), or at any stage after that up to and including the blastocyst stage (5-7 days ...
-2
votes
2answers
124 views

Why isn't the human zygote considered a human life how is a living anatomically modern human defined biologically? [closed]

It has 46 chromosomes by default when healthy(Differences almost always are pathological) and has almost every biological functions, processes a Newborn or and Adult person has. It even invades ...
3
votes
1answer
203 views

Cerebral/Cerebellar Cortex versus Deep Nuclei

I have troubles using the terms Cortex & Deep Nuclei, and 'Nuclei' in general. From what I understand, a brain has '3 matter types in accordance to anatomical locations' Superficial Grey matter - ...
-1
votes
1answer
55 views

Sexual Reproduction in Humans

Is the human egg cell (ova) considered motile? We know that is is not actively motile but it is transferred via the fallopian tube to the uterus. Does that make it motile?
0
votes
1answer
31 views

Protein inhibitory process

I usually find substances that activates proteins, like ApoA-I, but I don't find substances that inhibit it. So in an experimental design, could I consider the absence of a drug that directly acts ...
3
votes
1answer
109 views

What is a deep exhalation/inhalation?

I tried to find the academic definition of deep exhalation/inhalation but found nothing special. I speculate that the correct definition is as follows: • Deep ...
1
vote
1answer
56 views

Are your finger muscles and tendons interconnected?

Are finger muscles and tendons interconnected? If they are interconnected, then if i exercise one finger will it train the other fingers since they are interconnected and share the same muscles in the ...
4
votes
0answers
60 views

Optimal carbon dioxide concentration range for the human body

Previously I had thought the maximum concentration of CO2 for human health to be given by the ‘Pettenkofer CO2 level’ with a maximum of 1000 ppm. But according to this post a growing body of ...
2
votes
1answer
42 views

RE: Fasting gastric pH vs Normal gastric pH

If fasting gastric pH values are more acidic then why is it recommended to eat no more than three hours before bed time to prevent reflux. It seems at some point during sleep the stomach would become ...
0
votes
1answer
79 views

Does vitamin D affect melanin concentration?

I am aware of the affect on vitamin D production by melanin (in sunlight) but I can not find any information regarding a reverse connection.
6
votes
1answer
111 views

What percentage of the human genome hasn't been sequenced yet? If percentage estimates aren't precise, why is it difficult to estimate?

What percentage of the human genome hasn't been sequenced yet? I have read different estimates, e.g.: https://www.genome.gov/human-genome-project/Completion-FAQ (mirror): "In the April 2003 version, ...
1
vote
0answers
33 views

What causes tenocytes to migrate from intact regions of tendon into the wound site, and how do they move?

The 2018 study {1} mentions that: The healing process of injured tendons includes tenocyte migration which occurs from intact regions of tendon into the wound site. What causes tenocytes to ...
3
votes
1answer
61 views

What differentiates neurons in different parts of the brain?

For example: what makes a neuron in the hippocampus of the brain different from a neuron in, say, the amygdala, or the frontal lobe, or anywhere else in the brain? Do neurons in different parts of the ...

1 2 3
4
5
47