48
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Accepted
Biological siblings possible with <9 months age difference?
What do you mean by siblings?
If by siblings, you accept cases of individuals having the same father but not the same mother, then of course, it is possible! Below, I will assume you are referring to ...
- 68.3k
28
votes
Where does my extra blood volume go after giving birth?
The extra volume of fluid is due to the fluid retaining effects of high oestrogen secretion in a pregnant human female. After this high level of oestrogen subsides the extra fluid is mainly eliminated ...
- 1,955
26
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Biological siblings possible with <9 months age difference?
Yes, this can happen in non-twins. There is a rare phenomenon that can occur in humans (and some other animals), called 'Superfetation'. This is when some time during pregnancy, a woman has a second ...
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21
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Where does my extra blood volume go after giving birth?
The actual blood cells just get circulated out over time (e.g. broken down in the spleen). Eliminating the fluid is the easy part - consider how easy it is to drink a liter of water, absorb it and add ...
- 231
20
votes
Accepted
Could a man be proved positive for a pregnancy test?
Pregnancy test, just like any test, has some non-zero false positive rate. So yes, of course a test could be positive when a man pees on it.
Pregnancy tests work by detecting the presence of a ...
- 68.3k
20
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Biological siblings possible with <9 months age difference?
I have known kids who were 7 months apart in age - the younger one was a premature birth. No human intervention or other special circumstances required.
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15
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Biological siblings possible with <9 months age difference?
It's quite possible. Consider a couple who has problems conceiving children, so they get a surrogate mother who carries the couple's child. And six months later, with the psychological pressure gone, ...
- 425
14
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Biological siblings possible with <9 months age difference?
Women with uterus didelphys have two different uteruses, and hence can be pregnant with two sons at the same time. The time of fertilization for the two uteruses can be different.
The wikipedia page ...
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7
votes
Accepted
Why is sugar absorbed very fast into the blood stream?
In short, sugars are absorbed quicker than proteins and fats because they pass through the stomach quicker and their digestion is simpler.
Sugar can be absorbed through the mouth mucosa when applied ...
- 8,104
6
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In men, why do over 80% of sperm have abnormal form?
So I've dug a bit into how a 'normal morphological' form is defined and characterised, since assessing morphology into 'normal' and 'not normal' is always a very tricky thing.
Looking into the ...
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5
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Could a man be proved positive for a pregnancy test?
Yes it is possible. Pregnancy tests detect human chorionic gonadotropin (hCG), which in a healthy male can be produced by the pituitary gland. hCG consists of two subunits and the urine tests target a ...
- 1,305
5
votes
Accepted
Gestation period of African savanna elephants?
The African bush elephant and the African savannah elephant are the same species (i.e., they are just different names for Loxodonta africana).
According to here and here, the African savanna/bush ...
- 30.3k
3
votes
Biological siblings possible with <9 months age difference?
Surrogacy. Full siblings can be born at any age separation at all.
Medical intervention. I'm sure I've heard of one (non-identical) twin being delivered early by C-section for the purposes of surgery, ...
- 131
3
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Has the gestation (pregnancy) period for humans always been 9 months?
human gestation period
According to the link gestation period doesn't vary much between great apes.
I don't see any signs that human are becoming "more complex". In fact human babies are uniquely ...
- 161
2
votes
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Do pregnancy and breast feeding increase basal metabolic rate?
Basal metabolic rate for a particular organism is determined by the amount of calories that the organism needs for basal metabolic processes (i.e. basal energy demands). Since pregnant and ...
- 2,387
2
votes
Accepted
Why placental progesterone suppressed or drop before onset of labour?
Pregnenolone -the precursor of progesterone is principally converted to estradiol instead of progesterone.Thus the oestrogen:progesterone ratio increases prior to parturition.
Fetal cortisol ...
- 1,955
2
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Has an ectopic pregnancy's blastocyst ever been made to implant?
Not in an independently confirmed case.
A paper was once published claiming this was performed successfully:
Pearce JM, Manyonda IT, Chamberlain GV. Term delivery after intrauterine relocation of an ...
- 46.5k
2
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How is in-vitro fertilization technically achieved?
After following user David's hints, I have collected some videos that answer the questions I posted:
Regarding to needle manufacturing, there exist machines able to create micropipettes (this is how ...
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1
vote
Can 2 eggs come from ONLY 1 ovary?
The answer to this is yes, you can have fraternal twins. I don't know the likelihood of this happening, and I don't think there is any literature on it in the scientific community.
There is a ...
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1
vote
Accepted
Has an ectopic pregnancy's blastocyst ever been made to implant?
Yes, this has been done by
Wallace, C. J. (1917) Transplantation of ectopic pregnancy from fallopian tube in cavity of uterus. Surg Gynecol Obstet 24, 578-579
Shettles, L. B. (1990) Tubal embryo ...
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1
vote
Accepted
Oocyte cryopreservation: genes from three parents?
In short: yes it is possible to donate an oocyte to another woman. This is typically done in assisted reproduction and combined with in vitro fertilization. The child would only inherit the genes from ...
- 747
1
vote
Accepted
Is it possible to Breed an Animal to have more Females than Males?
Yes.
What you are looking for is a meiotic drive, it's a genetic factor that favors its own transmission. Sex linkage is very common in these due to sex chromosomes not undergoing recombination. Once ...
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1
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What evolutionary reason is there for hemolytic disease?
Hemolytic disease is not a genetic disease. It is a drawback of how the immune system works. In general, the overall benefits of having the immune system as it is right now are way higher than ...
- 3,128
1
vote
Accepted
Which variables are controlled in the mammalian womb to ensure a healthy environment?
It seems you are referring to this recent advance:
http://www.sciencemag.org/news/2017/04/fluid-filled-biobag-allows-premature-lambs-develop-outside-womb
https://www.nature.com/articles/ncomms15112
...
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Can only fully matured sperm fertilize an egg?
As far as I know, sperm cells undergo maturation in the epididymis, where they become motile. As Eliane pointed out, this is a continuous process, so the male does not have to "wait", because there is ...
Only top scored, non community-wiki answers of a minimum length are eligible