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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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Regarding detection of pregnancy during post mortem

Is it possible to detect pregnancy in a woman who is dead considering the fact that she did not a have a showing belly.
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1answer
45 views

If fully colorblind people only see shades of white,gray, and black, does that mean that the colors black, white, gray are colors humans can’t see? [closed]

And since the brain can be tricked to thinking that objects with mostly black and grey gradients are moving, like optical illusions, does that mean motion has a color?
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2answers
98 views

Is it ok to keep primers at 4 degrees?

I reconstitute my primers in nuclease free water ( no sterilised) this morning and I forgot them at 4 degrees, acording to the instructions, they should be storage at -20 after the reconstitution. I ...
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0answers
11 views

Increasing my PCR efficiency to be able to better visualise my bands

I run an electrophoresis in agarose gel and my expected bands are extremely week, is even hard to see them. It looks I need to increase my PCR efficiency. I have read about a Hot start setp, which ...
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0answers
15 views

CETP inhibitors and LDL levels

While CETP inhibitors effectively reduce LDL, they also paradoxically increase the frequency of adverse cardiovascular events (angina, revascularization, myocardial infarction, heart failure, and ...
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2answers
69 views

Comparison of humans and other primates in milk production amount

Do human females produce more milk (relatively to average child weight weight) than other primate females? Are human females more likely to feed several children through breastfeeding than other ...
8
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1answer
192 views

Do breasts size depend solely on fat amounts?

I've read the first answer here on quora and it suggests that (not during pregnancy and breastfeeding) breasts differ in size only due to the amount of fats. However, there can be firm or soft breasts ...
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1answer
52 views

Do decibels matter if the sound is outside human hearing?

I bought a dog training device that emits sound at 25K hertz and 130 dB. Can this damage anyone’s hearing since they can’t hear it? Also is it possible for an infant to hear in the 25K hertz range? ...
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2answers
102 views

why don't antibiotics reduce our weight?

I know that a significant weight of the human body (in Kgs) is contributed by microbiota. I also know that antibiotics can often be broad spectrum and kill all the bacterias regardless of them being ...
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1answer
65 views

Does night mode on iPhone really help?

Okay so I know that night mode is supposed to filter out blue light that is bad for the eyes, but is it really more helpful than annoying? At night I do use it when I’m on the phone but it doesn’t ...
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44 views

Is Rh factor an evidence for human evolution from primates?

The Rhesus Factor is an important blood antigen that is found on Rhesus macaque and human being. So is this an evidence for human evolution from monkeys. ???
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27 views

Lactate space computation

I want to compute the volume of lactate space in a human body. If you have available a body composition data (muscle mass, water content of a body) from a DEXA scan, how do you compute "lactate ...
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2answers
451 views

What's the current conclusion about humans being omnivores vs herbivores?

What's the current conclusion about humans being omnivores vs herbivores? And particularly, how is this relative to time? That is, is possible herbivoreness a "strictly" modern phase in human ...
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1answer
109 views

Why does applying pressure to a venipuncture site prevent haematoma?

From what understand, when drawing blood, a phlebotomist puts pressure on the venipuncture site while withdrawing the needle to prevent a haematoma. I'd like clarification; How does this prevent a ...
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1answer
26 views

Would retroviruses rapidly evolve to kill the host

Since retroviruses evolve rapidly. Therefore they would kill the host and never be viable. Transmission would not occur. I think this is why all synthetic retroviruses are continually renewed and ...
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0answers
28 views

how can I decrease noise in my staining and increase the signal?

I am trying to stain LN sections (from mice), for Madcam-1 using Madcam purified ab as primary and anti-Rat Cy3 ab as secondary. I have tried many times, very few times worked Ok but most of the times ...
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1answer
85 views

BMI limits in interpretation in people with high/low heights

In a study, I measure BMI of a large sample of adult people. Among them, there is some who have very low and very high height. As I can read on the internet (like here or even in the wiki, for ...
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1answer
74 views

What is the mechanism by which quitting smoking causes increased appetite?

I guess it has something to do with sugar regulation. Does anyone know something more about this?
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1answer
22 views

NADP and NADPH in in vitro metabolisme test

I did an in vitro metabolism test using chicken liver S9 as the source of the enzyme. I did two different of method experiment. one was using NADP and second was using NADPH as the co-factor. my ...
2
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0answers
68 views

Book recommendation for studying biology for neuroscience [closed]

I will be starting a double degree in neuroscience and mathematics very soon, and I realised that an understanding of human biology can really help me out, and so I'm looking for an introductory level ...
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1answer
50 views

If a person is infected with an RNA virus what percentage of the RNA in the blood of the person contains RNA of the virus?

Karius uses DNA sequencing of everything that's contained in a sample to detect all bacteria and DNA-viruses in the sample. Given the way that costs of sequencing are falling this approach seems to be ...
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1answer
180 views

Is plaque formed even if you do not eat anything?

Some people report that their gum and dental health improves when they are fasting. Many forums contain crazy amounts of misinformation and claims which are unsupported by serious scientific research, ...
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0answers
14 views

Are there any small lumbar forward flexors?

I've been looking into the smaller muscles in the spine such as the intertransversarii, interspinales, and rotatores. To my understanding, they are capable of spine extension, rotation and lateral ...
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0answers
12 views

stabilization mechanism

I am trying to simulate a soma with sealed end in both side and injected current in the middle of the soma. I used Na K and Ca voltage gated channels to get a concentration inside soma. I got a result ...
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2answers
158 views

Melatonin production, sleep, and “cyan light”; how might this finding be possible?

The BBC News article Cyan colour hidden ingredient in sleep describes research that suggests melatonin levels as measured in saliva could be affected by the presence or absence of cyan color in a ...
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1answer
45 views

What is meant by “a codon codes for an amino acid”? [closed]

What is meant by "a codon codes for an amino acid"? Does it mean in order to build that amino acid you must combine those three nucleotides? Does it mean anything more than provides the instructions ...
3
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1answer
75 views

Can men also become only bald on their legs?

Often hair loss that primarily affects the top and front of the scalp will happen to men (and female) during aging. Male pattern hair loss is believed to be due to a combination of genetics and the ...
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0answers
15 views

Without mutations would everything die from homozygosity?

It seems like without mutations no new genetic information would be created. Therefore genetic diversity would only diminish over time. Is this the case?
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1answer
57 views

Does estrogen increase muscular growth in females?

Regarding humans it is said that most psychological effects caused in men by testosterone are caused in women by estrogens. There are many studies on that, particularly regarding temporary shifts of ...
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0answers
34 views

how can I get stronger staining for my lymph node sections

I am using the same protocol and same antibodies that the literature says but still I cannot get good staining for my lymph node sections, I tried to change the fixation method and I am using now ...
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0answers
21 views

Why crackling the limbs in stretching?

In severel times I hear crackle nois when I stretch my limbs after a long time immobility. What cause this noise? Is there any connection with immobility or other (un)activities?
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0answers
31 views

Hepatocytes polyploidy

Why are some hepatocytes polyploid?
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0answers
42 views

Which DNA would sperms contain from a transplanted scrotum?

We had a discussion at the coffee break today about transplanting a scrotum. Let's assume that it's possible. Would the produced sperms contain the DNA of the donor or the one that got the scrotum ...
3
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1answer
821 views

Ligaments at the posterior superior iliac spine

In Causes of Back Dimples, it was determined that these 'Dimples of Venus' are created by a short ligament stretching between the posterior superior iliac spine and the skin. They are thought to be ...
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1answer
46 views

Why does the right bundle branch not have any terminal filaments in the IVS of the human heart?

Dubin's "Rapid Interpretation of EKG's" briefly describes this part of human physiology but doesn't explain the reason behind it. Is there a specific advantage of the human heart having this ...
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1answer
88 views

absorption time of zinc in the body

I would like to know how long it takes for the human body to absorb / digest a 10mg zinc capsule? Note: It is recommended to take zinc an empty stomach to gain the maximum effect. Regarding to that ...
3
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1answer
133 views

How can there not be purpose movement in the fetus until week 18, when a fetus can open its mouth and suck its fingers at week 11?

According to Fetal Movement According to an overview produced by the Royal College of Physicians of Edinburgh, purposive movement begins at about 18 weeks, gradually replacing reflex movements ...
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1answer
115 views

Causes of Back Dimples

What are the causes of the dimples commonly found above the buttocks? They seem to be in line with the sacroiliac joints. Do the joints have anything to do with them?
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25 views

Sound produced by muscle tightening

If you are at some quiet place, you will hear some mild noise when you tighten your jaw. Why is this? Is this sound produced by face/jaw muscle?
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0answers
34 views

What is the earliest point at which one can detect pregnancy?

Imagine a woman gets pregnant on day X. What is the shortest interval (like a day, a week, a month) after which she can detect she is pregnant? Example: Let's say that she keeps track of her ...
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1answer
73 views

What could an increase in systolic blood pressure and decrease in diastolic mean?

Sorry if this is a really simple question but my academic background is in completely different sciences. I recently made a computer game for an experiment that was related to anxiety and relaxation. ...
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0answers
16 views

Is there any biological evidence for the native american smallpox epidemic?

Scientists have found evidence from European graves that some people died of what may have been the black death. Is there any similar evidence for native Americans?
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1answer
63 views

what is CpG coverage? DNA starting material?

referring to this quote from an article about predicting methylation states: "Because of the small amounts of genomic DNA starting material per cell, single-cell methylation analyses are ...
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3answers
223 views

How much energy we get from oxygen?

During a whole day breathing, how many kcal or watts do we get from the oxygen we breathe?
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0answers
19 views

What determines which symptoms an allergen will cause? [closed]

Allergies result in many different symptoms such as sneezing, runny nose, itchy eyes, coughing, rashes, swelling of the face, stomach pain, vomiting, dry skin, anaphylaxis, etc. An allergen can ...
2
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1answer
30 views

Growth mediums required for human cell cultures

So i would like to try a culture some of my keratinocytes just to see if i can do it. Ive read about a few different types of growth medium such as DMEM and RPMI but i am not sure about when to use ...
2
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1answer
62 views

Do fruit juices have a diuretic effect & what governs this?

Was just contemplating this. Juices tend to contain a lot of sugar. Does the body absorb all the sugar in juices? If the body does not, that sugar must be excreted by the kidneys alongside water ...
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0answers
110 views

What is the average volume of the human Psychic tear? (“emotional tear”)

My goal is to find out the volume of the average human "emotional tear" (Psychic tear - sadness, happiness), specifically when crying. I found a lot of information about Basal tears (constant ...
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0answers
15 views

Lifelong Immunity Question Regarding Erysipelas And Scarlet fever

So my question is after you carry on Scarlet fever you develop lifetime immunity. But with Erysipelas you might develop recurrence type. What is the mechanism behind it? Both diseases are caused by ...
2
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1answer
63 views

Why do humans have digestive system present at front and kidneys back?

Outlet of digestive system is present at back of the body but its digestive system at front. Outlet of urinary system is present at front of the body but its system present at back. Why do humans ...